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17. TECHNICAL DETAIL The Electric Telegraph, then and now, 1859 Context Carl Friedrich Gauss and Wilhelm Eduard Weber constructed the world's first electro-magnetic telegraph in Göttingen, Hanover, in 1833. It consisted of an induction-coil transmitter, not a galvanic source, and a galvanoscope as the receiver. The one kilometre long over-house circuit of two iron wires was built between March and April 1833 to coordinate the use of astronomic clocks at three locations at the University of Göttingen, and later had several "speaking" codes devised for it. The world's first electro-magnetic telegraph was in use until December 1839. A small curiosity is that Hanover was a vice-royalty of the British crown, governed the Duke of Cambridge, until Victoria became queen in June 1837. In 1835 Paul Schilling von Cannstadt, a Baltic-German living in St Petersburg, Russia, displayed to an academic audience his five-needle galvanic telegraph, the first using simple galvanometers to indicate messages. He was commissioned to make a line from St Petersburg to the Imperial village of Tsarskoe Selo in 1837 but died before commencing the works. Carl August von Steinheil constructed a six kilometre long, two-wire circuit between his campus at the Academy of Science and the Royal Observatory in Munich, Bavaria, in 1836. This was worked by Steinheil's galvanic printing telegraph which had two nibs controlled by electro-magnets writing dots on a moving roll of paper. This was the first printing telegraph. Steinheil's subsequent telegraphic inventions included the single wire and ground return circuit, the needle telegraph worked by current reversal, the acoustic telegraph using two bells with different notes, as well as the printing telegraph using "dots", groups of which made to emulate the forms of printed roman letters (only vaguely, it should be said).As will be seen the subsequent decade saw the true innovations of Gauss and Weber, Schilling and Steinheil re-invented in several guises.
British Telegraph Codes 1868 Railways or Roads? Only the British Telegraph Company used its general powers to attempt short roadside overhead wires in the 1850s where it could not gain a railway wayleave. Its pole circuits along roads led to public objections, from their intrusive nature and from the damage caused to the trees that lined most of the coach roads. The overhead wire circuits on open roads were also particularly vulnerable to vandalism. At the end of the decade the Magnetic Telegraph Company was compelled to adopt roadside over-head wires when its many long underground gutta-percha cables began to decay in 1858; extending them even into city centres, high over the tops of houses. It was only able to do this by licensing the powers of the British company, which it absorbed in 1857. The Magnetic’s protégé, the London District Telegraph Company, also “borrowed” the British company’s Act to enable its over-house wires in the capital. In the 1860s the United Kingdom Electric Telegraph Company was the first to generally adopt overhead or pole circuits alongside of the city to city coach roads. It met with immense public opposition, particularly from landlords with country estates and other property bordering the highway being “poled”. This hostility was encouraged by the competitive companies. The United Kingdom company was compelled to seek another Act permitting it to use overhead roadside circuits in 1863 after failing to agree terms with the individual who then owned its original 1851 rights. It was compelled to place poles along canal banks until then. The Universal Private Telegraph Company’s Act of 1861 granted it the right to use roadside overhead wires. Eventually the Telegraph Act 1863 gave general powers to all companies. A significant technical detail was that at this time the British domestic telegraphic circuits were not in continuous charge; unlike in the United States where the line was always 'live'. The electrical source was only applied when messages were to be sent, that required was moderate by comparison. Construction of domestic lines of telegraph in Britain was undertaken, with minor exceptions, by the companies themselves. They engineered the lines; employed and managed the necessary labour gangs directly, without the use of contractors. Iron wire, insulators, underground cable and iron conduits were purchased from manufacturers for both construction and for maintenance, by-and-large, to the companies' patents and design specifications. It is clear from their annual reports that large quantities of telegraphic stores were maintained by the companies for maintenance, renewals and new lines. There was a difference with regard to underwater cables: the Electric company laid its own, the Magnetic and Submarine relied on contractors.
Classified List of Electric Telegraph Patents
until the expiration of Cooke & Wheatstone's first patent
Compiled by Charles Coles Adley for the
*For Telegraphs and Insulation or Suspension of Wires. Apparatus In 1845 the Electric set up workshops to manufacture instruments, and all of the companies bought instruments and components from patentees and manufacturers. Manufacturing and maintenance continued at the Electric and Magnetic companies' own workshops. In general between 1840 and 1870 public telegraphs in Britain used needle instruments for sending and receiving messages, connected from the earliest days by pole-suspended, overhead wires retained on insulators made of earthenware pottery, worked with galvanic batteries. The needle instruments, almost unique to Britain, indicated the telegraphic message on a large dial by means of one or two index hands ('needles') moving either left or right to indicate the elements of a code or cipher. Each needle was worked electrically from behind the dial face by a small galvanometer. The sending mechanism could be one or two small cylindrical commutators or switches worked by handles; or by keys (the latter known then in Britain as 'tappers' or 'pedals'), both connected to batteries; or by small magneto-electric devices (what might be termed pulse-generators) without batteries.
Charles Wheatstone's five needle telegraph 1837 The First Telegraph
The original copper wires used on the earliest circuits were insulated by a covering of cotton or silk laid spirally over the wire; the cotton was steeped in india-rubber to protect it from the damp and then immersed in pitch and laid in wooden battens or small-bore iron pipes. The battens were buried in the earth. The pipes were mainly carried on short posts, but were also laid in the dampest conditions underground, even underwater. As an example, ten wires were laid in a two-inch diameter iron gas-pipe alongside of the London & Blackwall Railway in 1841. Cooke was to introduce a weight-driven air-compressor to keep the iron pipe pressurised and so free of water. The pipe joints were never air- or water- tight and the caoutchouc resin eventually cracked in heat.
The short-lived circuit on the Great Western Railway between Paddington and West Drayton worked from September 1839 until about February 1840 utilised W F Cooke's four-needle instruments with his "butterfly" keys, and five wires (with another spare). Cooke's "butterfly" key or rotating switch 1837 Other early instruments introduced by Cooke & Wheatstone were the single- needle telegraph, needing just one wire, used on the London & Blackwall Railway in 1841 and the two-needle telegraph requiring two wires, first tried beside the Edinburgh & Glasgow Railway in 1842.
The American Telegraph Before that, Morse had attempted to introduce in June 1838 a "homespun" version. The first receiver was contained in a wooden case; with a simple wooden clockwork drive for a paper strip and a needle on a metal rod moved by an electro-magnet. The transmitter used a wooden comb with separate, moveable teeth representing code elements to dip the tip of a pivoted arm into cups of mercury to make or break the circuit. It also had a similar repeater or relay using a pivoted arm and mercury cups on a wooden frame, copied entirely from Cooke and Wheatstone's patent of 1836. These elements were eventually included in Morse's initial American patent of June 20, 1840. None of them were ever used in practice.Morse's first telegraph receiver 1838 Morse's first electro-magnetic relay 1838 Morse's first sending device 1838 The "perfected"version of 1846 consisted of a 'key' to make and break an electrical circuit, a 'register' or 'embosser' that had an electro-magnetically-controlled point scratch a mark on a mechanically-driven roll of paper, and a 'relay' that took the weak line signal and amplified it in a separate local circuit to work the register. The 'register' was a substantial piece of equipment, now entirely constructed of brass and iron, requiring a strong current and a clockwork source. It had to be kept wound-up and to be turned on when a message was signalled. In Europe, by 1856 the scratching mechanism was replaced by a sensitive inking device, the "inker", that printed dots and dashes on the tape, and which required far less pressure and electrical current, rendering the local relay unnecessary. This improvement was devised by Thomas John, an official of the Austrian kaiserlich-königlich Staatstelegraph, in 1854. The 'key-and-writer', rather than the 'key-and-register', was the working mode of the American telegraph in European service from the mid 1850s. The American Telegraph 1850 So, unlike its parent, the American telegraph in Europe developed in sophistication throughout the 1850s and 1860s. The original version, the "embosser", used by the Electric Telegraph Company from 1853 and made by Siemens & Halske, was replaced in the Company's service by Meinrad Theiler's "disc" inker in 1857, this had a thin wheel revolving in a reservoir of ink on the end of the lever instead of the original iron pin. Siemens in Berlin soon produced their own version of the "disc" inker in 1862; this soon dominated the north European market for telegraph receivers. In 1860 Digney frères in Paris developed the "bottle" inker, in which a siphon replaced the disc as the marking mechanism. The famous instrument maker, Breguet, also produced his own version of the Theiler disc inker, making the tape immediately readable by the receiving clerk. Both the Siemens and the Digney inkers were used by telegraph companies in Britain. Apart from the increased clarity in marking the message tape, the sensitivity of the inker over the embosser allowed for the abandonment of the local circuit and relay with its separate battery in all but the very longest circuits.
The reading of the scratch marks on the
tape of the original register was in any case difficult and in America
operators learned to interpret the movements of the device by its sound. By
1859, much against the wishes of S F B Morse, the "sounder" or acoustic telegraph
was in common use on American circuits. This was a simple, small electro-magnetic
device that clicked in time with the distant key, replacing the old register of
1846. The sounder was a great economic improvement over the old register. In 1861 William O'Shaughnessy said that the Indian government telegraph monopoly was saving £3,000 per annum after replacing its American registers with sounders. The Magnetic Telegraph Company in Britain also claimed in 1864 that its Bell apparatus, another acoustic receiver, saved it "several thousands" in a year over American 'writers'. It was subject to other criticisms, particularly in regard to its accuracy and security. It needs to be emphasised that all the telegraphic terminal instruments described required constant attendance. There was in this period no apparatus that received a message entirely automatically. The needle and dial telegraphs needed a clerk at either end to send and receive. The American registers and writers and the type-printing telegraphs all had to be manually switched into the circuit on receiving an alarm from a distant station and the clockwork mechanisms needed to be often spanned to assure uninterrupted traffic. A significant early change in technical operation was the move away from instruments requiring a two-wire circuit with earth returns to the much more economical single-wire circuit with earth return. This applied particularly to the two-needle telegraphs of the Electric and Magnetic companies; most contemporary and all subsequent devices used a single-wire circuit. Turnplates 1855 Auxiliary Instruments ![]() Cooke's Detector and a 24 plate Cooke sulphate 'sand' battery 1847 Most telegraph offices in Britain were equipped with at least one desk-top galvanometer or a portable detector to measure the current in its lines and the state of the batteries. In appearance these were small single-needle instruments in fine wood cases, calibrated in degrees to record greater or lesser current. ![]() Cooke & Wheatstone Paratonnerre or Lightning Protector 1847 The other common device in all offices was the lightning protector or paratonnerre which diffused the effects of extreme static electricity that otherwise might damage instruments and injure clerks. There were all manner of contrivances for this purpose, affixed to walls or on working desks in circuit between the instruments and the line of wire, with their own lead to earth. Cooke & Wheatstone Alarum or Bell 1847 Cooke & Wheatstone Tunnel Bell 1847 Each early signalling telegraph worked in
concert with an alarum, now spelled alarm. This drew the attention of the clerk
to activity on the circuit. Those of Cooke & Wheatstone used an
electro-magnet to release a clockwork-driven rotating hammer to continuously strike
a bell until stopped manually. The alarums gradually went out of use in urban telegraph
offices but were retained in remote stations where the clerk might be absent. The
principle was adapted to remotely sound very large warning bells at the mouths
of tunnels and similar points of danger. Underground Cables All the extant companies constructed subterranean circuits for their trunk lines during that short era, virtually abandoning overhead wires to railway signal telegraphy. Although more secure these circuits required a much greater current; six twelve-cell batteries could work 200 miles on a well-insulated iron-wire pole line but only 100 miles with a gutta-percha insulated copper-wire cable. Then, in 1859, there were catastrophic electrical failures on a great many underground circuits as the gutta-percha insulation oxidised in air and disintegrated after several years' exposure. In 1849 the extensive subterranean Prussian and Danish telegraph systems built by the Siemens firm on a much cruder technical base, using "sulphuretted gutta-percha", laid under 24 inches of soil in a lead sleeve, had similarly collapsed after just a few months' service. Sulphur had been added to strengthen and improve the insulative qualities of the resin; but in addition it caused the copper to dissolve and in some instances the small current created a chemical reaction that ignited the gutta-percha. This latter effect was used to create the simple "Statham's Fuze" for detonating explosives by electricity.Fortunately, the sale of the copper cores of the underground resin-insulated wires met a substantial part of the costs of replacing them with overhead pole lines. With regard to underground (and to underwater) circuits it was found during experiments between 1859 and 1861 that the composition of the materials used was critical; there were large differences in the purity of copper metal, and gutta-percha was found to be delicate in its composition with air-bubbles, contaminating fibres and unexpected internal weaknesses, as well as sensitive to temperature. A major cause of electrical failure was in the jointing of the copper wires where lapping and soldering together made the core brittle. There was argument over the merits of india-rubber over gutta-percha as an insulator. India-rubber was found to be the better electrical insulator, easier to join and more consistent in manufacture than gutta-percha, although its properties were such that it could not be drawn through dies for continuous covering. For a short period in the early 1860s india-rubber was the more popular medium used to insulate under-ground cables, internal circuits and for insulators on overhead wires on poles. Caoutchouc or india-rubber had been advocated and used as an insulator for wire since 1838 by Charles West. He had unsuccessfully promoted a cable to France in competition with the Brett family, and had laid the earliest successful submarine telegraphic cable one mile across Portsmouth harbour for the Admiralty in 1845; it was still in use in 1860. West was engineer to several unsuccessful cable companies, including the Irish Sub-Marine company, and later became associated with S W Silver & Company, long- established manufacturers of caoutchouc goods. He developed with them a machine for spirally-winding thin india-rubber around copper wires to create cable cores. Silver & Co patented and manufactured underground and underwater caoutchouc-insulated cables and hard-rubber insulators for poles. However india-rubber was found on investigation and experience to be far less durable, being especially vulnerable to oxidisation in sunlight and general decomposition though weathering and age. All of the issues raised were addressed with new processes. The sourcing of fine copper and its refining was immediately improved. So-called "pure gutta-percha" was introduced in 1861 that eliminated the contaminants and faults, and it regained its precedence in underground and underwater cable insulation until synthetics were introduced almost a century later. There was, however, a general re-adoption of pole telegraphs in the 1860s for long distance lines and a flurry of patent applications for new insulators for overhead wires. Unlike in America the insulators used in Britain on these poles were not glass but glazed earthenware. In the period between 1838 and 1868 there were patents covering improvements in these so-called porcelain insulators, as well as a number later in the period using natural resin (ebonite, a form of vulcanised india-rubber) and resin-impregnated wood. Cooke's Telegraph Costs In 1843 W F Cooke published in the railway press his detailed costings of the two forms of telegraph that he had erected on the Great Western Railway: Iron Tube & Post of 1838 Total cost per mile - £287 6s 0d "to which a percentage for casualties, profit to the contractors, and the price of instruments remains to be added." New Overhead System of 1843● Drawing posts, with winding apparatus, per mile - £40 0s 0d ● Cast-iron standards with insulators (22 in a mile), per mile - £52 0s 0d ● Labour in fixing and painting, per mile - £12 6s 0d ● Anti-corrosion paint and tar, per mile - £11 0s 0d ● Carriage, tools and sundries, per mile - £13 0s 0d ● Contingencies, per mile - £13 0s 0d Total cost per mile - £149 6s 0d
The principal technical differences between the companies in Britain were: a.] The Electric Telegraph Company In addition to these large desk-top instruments for public office use by 1850 the Company had utilitarian portable two-needle telegraphs for external use. These were in small rectangular oak bodies, carried in a leather case; the glazed front being protected by a slide-out wooden panel. Uniquely they had four finger keys on the back panel, two at either side, so that it could be hand-held for working. Connection to the line wires was made by a row of four brass screws also on the back, along the top. The glass front was hinged at the side, with a button on its face to move the side pins of the two needles back so as to turn it into a galvanometer. Cooke & Wheatstone's Two-Needle Telegraph The single-needle telegraph worked by a drop handle, with a single-wire circuit, introduced in 1848, was the Company's commonest apparatus in its public circuits from the mid-1850s until 1868. The single-needle telegraph of Cooke & Wheatstone had the unusual nickname of toujours prêt,
always ready, as unlike the clockwork-driven American and Bain
instruments it required no preparation to be put in service. The name
is said to have been introduced by the telegraph contractor, William
Reid. Described in the 1840s, "each needle was suspended in a light hollow frame of wood or metal, round which were wound two sets of fine copper wire, coated or insulated with silk or cotton. About 200 yards of fine-gauge wire is used. To prevent oscillation the lower point of the needle was slightly weighted. Below the needle was a handle, so formed as to turn on or break off the connection with the battery with the conducting wires, so to transmit motion to the needle, deflecting it either right or left." The Cooke & Wheatstone's original coil for the needle telegraph of 1846 was six inches tall, Nathaniel Holmes improved the winding and introduced shorter, fatter astatic needle pairs that reduced the size to one inch in 1848. Latimer Clark designed further improvements, and Samuel Alfred Varley devised "undemagnetizable" soft-iron cores for the needle coils in 1866. The
advantages Cook & Wheatstone's two-needle instrument possessed over
Bain's and the American telegraph were stated in 1854; that it did not
demand the same skilled hands to wind and adjust the machine and
prepare the paper; it was always ready at hand, and only needed
attention at long intervals; its disadvantages were, that it did not
trace the message, and consequently left no telegraphic record for
reference, and it required two wires, while the Bain writer and the
American telegraph employed one; the current required to work it was
the same as the former, and rather less than the latter. ![]() Cooke & Wheatstone's Portable Two-Needle Telegraph 1850
For use as a telegraph and a galvanometer. The four white and black buttons to the sides of the back panel worked the telegraph needles, along with six brass connectors for positive, negative and earth wires, top and bottom. Pictures from the Science Museum As well as on the Electric, Cooke & Wheatstone's two-needle telegraph was used between 1852 and 1854 on the circuits of the Submarine Telegraph Company between London, Dover, Calais, Brussels and Paris. The original two-needle code of 1843 had an alphabet of just twenty letters and ten numbers on a single square dial. By 1852 this had been replaced by a twenty-five letter alphabet with no numbers; the numbers were then spelled out as words. At the same time "twin-dials" were introduced, being two single-needle dials set in a single face allowing for economy in manufacture, worked by drop-handled commutators. These dials replaced the original six-inch coils of wire working behind the needles with compact one-inch coils. The master and subsequent patents it acquired of Cooke and Wheatstone effectively locked-out all competition until 1852. The Company regarded others, especially Morse, as intruders.Cooke & Wheatstone's Telegraph System The development of the needle code from 1840 to 1853 Cooke & Wheatstone's Two-Needle Code 1843 Cooke & Wheatstone's Two-Needle Code 1852
As well as two-needle and single-needle instruments W F Cooke had patented the fault-finding detector,
the principles of pole suspension, the principles of conduit
wire-laying, lead-sheathing for subterranean wires and a variety of
earthenware insulators for pole telegraphs. The Company also offered
Wheatstone's magnet-and-bell device
to railways and others, such as factories and mines. This consisted of
a large finger-pedal or key that worked a horseshoe-shaped magneto;
pressing the key produced a single pulse of electricity. The distant
receiving instrument was an electro-magnet that attracted the
spring-loaded striker of a brass bell. Each stroke of the key had the
bell sound once. It was the first commonly used magneto-telegraph, that
is one without galvanic batteries, and the first acoustic telegraph.
The magnet-and-bell was manufactured until the 1870s for signalling in
mines. ![]() Cooke & Wheatstone's single-needle telegraph 1868
The final version used on public wires and by the railways
for many years, into the twentieth century
The principal technical problem faced by the Company in
its early years was an understanding of insulation of the circuits. The
original circuits of wires in pipes were of such a nature that
transmitting messages up to just twenty miles was difficult. The
introduction by W F Cooke of overhead wires on poles insulated from the
earth by glazed earthenware discs in 1842 allowed distances of more
than one hundred miles to be worked successfully. It was the perfection
over time of the insulation along the line and within stations that
made the geographical progress of telegraphy possible. The ceramic insulators were originally attached directly to the sides of the pole; cross-bars on the pole were not introduced to the Electric's circuits until the mid-1850s. As noted Cooke's original insulator was a flat ceramic disc. The Company's first insulator was Cooke's earthenware barrel, No 1, the next was Edwin Clark's metallic-bell-topped earthenware model of 1850, No 2, perfected in 1851 as a wholly-earthenware bell, No 3; an interim double bell model to Latimer Clark's design was used from 1856; the last insulator adopted was Varley's double-bell earthenware model of 1861, No 4; each introducing improvements intended to reduce current escape through atmospheric moisture. Regarding progress in the insulation used on its overhead open wires, in 1868 the Company recorded that the new insulator of 1852 doubled the distance of line that messages could be sent direct. That introduced in 1853 rendered the circuits more weather-resistant. In 1857, a further improvement again doubled the distance of direct transmission, where three transmissions were used, only one was then needed. Finally with the new insulator of 1862 it became possible to telegraph from London to Edinburgh and Glasgow directly in all weathers, these direct all-weather circuits soon also included Aberdeen, Cork and Dublin.W F Cooke's earliest overhead or pole lines of 1842 on the Great Western Railway were formed of 9 foot cast-iron posts, much like the standards of street gaslights, with a 4 foot tall ash-wood headpiece to which short, separately-insulated vertical battens were attached on either side. The improved hollow, barrel- shaped insulators for the circuit wires were stapled horizontally to the battens; the wire was threaded though the core. The overhead iron wires suspended in the circuits of 1845 to 1848 were of No 8 Birmingham Wire Gauge, which is about 1/6 of an inch in diameter, and weighing about 480 pounds to the mile. It was welded into lengths of one-quarter mile at manufacture. The standards or poles were then set 45 to 50 yards apart. The only exception to this was the wire on the very first long line, that between Nine Elms and Southampton, which was to No 7 gauge.
These early lines had intermediate winding posts with a small drum and ratchet mechanism instead of a simple insulator for each wire by which tension could be adjusted every quarter-mile. The wire merely passed though the centre of all the other pole insulators, disc or barrel, on the line without being secured. The winder was soon
regarded as an unnecessary complication and the wires were then
tensioned between every pole and secured firmly to each barrel
insulator. The manufacture of ceramic insulators was not a speciality
business in the 1850s and 1860s. Many potters in England added
telegraphic "porcelain" and stonewares to their trade lists. One of the
earliest and largest suppliers was Joseph Bourne & Son, of the
Denby Pottery, Derbyshire, who were stone bottle and jar manufacturers.
They had the advantage of patent kilns for making the inexpensive
strong earthenware called 'stoneware'. The earliest insulators by W F
Cooke were made at Denby, and they continued in that line for a
century. By 1854 the Electric Telegraph Company was also purchasing
stoneware from John Rose & Company of Coalport in Shropshire, far
better known for their superior porcelain, and from Mayer Brothers
& Elliot at the Dale Hall Works in Burslem, Staffordshire, which
existed only between 1843 and 1861. These potters, and many others,
undertook the moulding, glazing and firing from patterns supplied by
patentees or by the Company. Round larch wood replaced squared Baltic fir for all telegraph poles from 1850. The poles cost from 3s 6d to 4s 0d each in 1853. Several patent processes existed for preserving timber. The first used for poles was Kyanizing, impregnating the wood with mercuric chloride, dated from 1832 and was used in the earliest lines of overhead telegraph in 1843; however the preservative rapidly corroded ironwork. Burnettizing, impregnating the wood with zinc chloride, was tried between 1844 and 1845. Eventually the simpler, cheaper Bethelizing process, dating from 1838, was adopted from 1848, which forced creosote into the wood of the pole under vacuum and did not necessarily require over-painting. The Timber Preserving Company was formed by Act of Parliament in December 1849 to absorb the firms that worked Bethell's, Margery's and Payne's processes for preventing rot in wood. It had offices at Whitehall Wharf, Cannon Row, Westminster, and undertook its operations at Durand's Wharf, Trinity Street, Rotherhithe on the River Thames. They offered to prepare railway sleepers and poles for telegraphs for 5d each.
Electric Telegraph Company's Wire Stretcher 1860 Poole's portable wire-stretcher was used for drawing the ends of iron wire together using two clamps connected by a system of levers so that they might be permanently joined. Moses Poole was a patent agent, so the real originator is not known. Only from 1852 did cross-bars secured by an iron staple appear on the Electric's poles as the need for more and more parallel circuits appeared. The Clark No 2 and No 3 insulators then being suspended from beneath the cross-bar; in 1861 the latest Varley No 4 insulators were screwed into the top of the cross-bar.
The
wire for overhead lines continued to be solid-drawn No 8 BWG
(Birmingham Wire Gauge) diameter galvanized iron, but now weighing 387
pounds a mile. In April 1859 C F Varley said that he was using much heavier No 3 BWG iron wires on the important long overhead lines at the side of the London & North- Western, Great Western and London & South-Western railways. He would "never again" use No 8 gauge iron wire on lines more than 200 miles in length as the thicker wire had far less electrical resistance. However, overhead iron wires on poles were not suitable for tunnels, under bridges and through the streets of urban areas. W F Cooke had patented the first underground cable in 1840. This consisted of up to nine varnished No 16 gauge copper cores each protected by tar-coated cloth, drawn in clusters of three or four through solid–drawn lead pipe, covered overall with a tarred rope outer. It was first laid under the footpaths to connect the Company's existing London offices in 1845 and then through tunnels along the London & Birmingham Railway in 1847. These very limited circuits, expensive and complicated to lay with their lead outer-sheath, lasted for twenty years. Electric Telegraph Company's Proving Box 1848 The Company eventually had a small network of underground circuits in most cities. They were laid to a common model in 3 inch diameter socket-ended cast-iron pipe sections, each 9 feet long, weighing 100 lbs, located under the footpaths of streets, divided into sections by proving- or test-boxes on 3ft high iron posts every 440 yards. The upright posts were later replaced by flush test-boxes set into the pathways; iron cases 28 inches long by 10 inches wide by 12 inches deep with flagstone covers, inset every 50 or 100 yards. The Electric Telegraph Company's First Underground Pipe 1848 As the iron pipes of the conduits were being laid a single iron 'leading-in' wire was threaded through. The subterranean cable of a copper core insulated with gutta-percha resin and protected by a serving of cotton or rope was prepared in 400 yard lengths on wooden bobbins. An iron frame fitted with two wooden rollers was positioned over a flush box on the piping; the cable was run between the rollers to avoid chaffing to be attached to the 'leading-in' wire in the pipe. The wire was then pulled through along with the cable by man- or horse-power. The Company's jointers numbered each circuit cable with metal tallies and then permanently connected the circuits as laying the line proceeded. These early subterranean wires were manufactured by J & T Forster, india rubber and gutta-percha manufacturers, of Streatham Common, Surrey. They had developed and patented a process for covering copper wire between thin fillets of gutta-percha resin in concert with C V Walker of the South Eastern Railway, during 1847. Its invention came after W H Hatcher, the Electric company's secretary and engineer, had suggested that the newly-discovered resin might be used for insulation in 1846. The actual processing machine was devised by William Henry Barlow, a civil engineer. The Electric company snapped up Forster's patent, but it was soon superseded by a better process. Originally, on its introduction in July 1849,
there were three No 16 BWG copper wires in each underground core
insulated with resin up to one-half-inch diameter. This was soon
abandoned as one failure disrupted three circuits, to be replaced with
a single No 16 BWG copper wire covered in gutta-percha to No 3 or 4 BWG
thickness. In 1850 double-coating of resin was introduced as a further
insulative measure and became general. The insulated cores were
protected by tarred cotton tape and sanded, and weighed 85 pounds per
mile.
The Test Box In keeping with the short-lived technical fashion of the 1850s the Electric company introduced long-distance subterranean lines insulated with gutta- percha. Edwin Clark adapted its existing underground city system in 1853 to lay eight separately-insulated copper cores bound together as a cable with sanded, tarred tape and jointed in quarter-mile lengths, within cast-iron or earthenware pipes for its so-called 'Express Lines' alongside of the London & North-Western railway between London and Manchester and Liverpool in the north of Britain, its busiest circuits. Insulation
of electrical wiring had become a monopoly of the Gutta-Percha Company
of Wharf Road, London. This used the Gutta-Percha Covering Machine,
patented by Charles Hancock in July 1848 and assigned to the
Gutta-Percha Company; the machine hot-rolled up to seven copper wires
with the resin through a die in a continuous process. By 1860 the Electric company, after the failure of gutta-percha underground, had reverted to overhead circuits on poles for all of its long lines; with a new system devised by C F Varley, using heavy gauge iron wire and new, more efficient insulators. Contrarily, to insulate its internal station circuits the Electric adopted india- rubber. Two miles were initially installed in 1852 at its Charing Cross office in the Strand from the battery room and between the instruments. This was some of the earliest manufactured by S W Silver to Charles West's process. During the 1860s the Company used Hooper's patent india-rubber insulation for most of its indoor circuits. Bain Chemical Telegraph 1848 Regarding other instruments, the Electric Telegraph Company acquired the rights to Alexander Bain's chemical telegraph or writer which indicated a broken line on electrically-sensitive paper strip, which it used between 1848 and 1862 on its busiest circuits. In his patent he used a "finger pedal" or key to transmit electrical pulses to a wire touching the surface of a strip of chemically-dampened paper. The paper strip was slowly drawn by clockwork from a roll between the wire and a small brass cylinder that formed the return circuit. Pressure on the "finger pedal" caused the wire to make a mark on the paper, either a short dot or a long dash. It was particularly sensitive in operation, requiring less current than other telegraphs, so much so that it was planned to experiment with it on the Atlantic cable of 1857. To counter-balance this sensitivity, the circuits of the Bain writer were particularly vulnerable to interruption by "atmospheric electricity". Alexander Bain had devised by 1848 his fast telegraph -
a variant of the chemical telegraph in which the "finger pedal" was
replaced by a miniature hole-punch worked by a small mallet and fed
with strips of paper. Messages could be prepared by several 'punchers'
and the paper strips fed into a rotary sender between a wire and a
hand-turned metal roller so that the punched holes made and broke the
circuit. This enabled the rapid transmission of messages irrespective
of the 'hand' of an operator. However the rotary sender and the
receiving writer had to be carefully governed to work synchronously.
The patent for the fast telegraph was immediately acquired by the
Electric company. In July 1847 the Company was reported to be
developing its own improvement of Bain's chemical telegraph. Its rotary
sending and receiving mechanisms were to be powered by steam
rather than clockwork, and be capable of sending and receiving 1,000 to
2,000 letters per minute. It, too, used punched tape, but their punch
was also to be worked by steam. Even if using rods and belts for
transmission of the steam power, it was fanciful. Only in 1868 was
pneumatic power to be adapted to punch holes in telegraph message
tapes. Clark's Perforator for preparing the paper tape used to feed the rotary sender attached to the Bain printer 1850 Latimer Clark, the Company's engineer, modified Bain's fast telegraph by introducing a much improved, speedier punch for the paper tape in the 1850s. According to G P Bidder, a director of the Company, by March 1852, using his punch the Bain printer regularly achieved 300 words a minute from tape. By this improvement, according to James Graves, in 1853, the Bain "printing telegraph had to be learned by punching with a three-lever machine which perforated the paper slip - one lever punched a dot or small square perforation in the paper, another punched a dash of three times the length of the dot, and the third made blank spaces where required, either between the letter, or between the words." About 1850 the Company experimentally adapted a Bain chemical printer to work with a long stick or rule of moveable metallic elements rather than with the finger pedal or punched tape. By this, short messages in code could be sent by drawing it under an electric feeler and printed on tape at an exceptionally fast speed, anticipating Bonelli's telegraph. It featured Bain's electric clock in all of its offices, having several in the Central Station at Founders' Court. This was a long-case time-piece in an oak body 4ft 6ins tall by 1ft 4ins wide. The normal clock face at the head read hours, minutes and seconds. The simple clockwork mechanism required no springs or weights but was regulated by a long pendulum at the base of which was an electrical coil in place of the usual bob. This was governed to move alternately between permanent magnets at either side of the body. A single pendulum might control several clock mechanisms. Bain advocated earth cells, zinc and copper plates or zinc and carbon in the form of coke buried in damp earth, to provide current; the Company used ordinary sulphate galvanic batteries for its electric clocks. It acquired too, Edward Davy's relay or repeater for extending its domestic circuits, an improvement on that patented by Cooke & Wheatstone, although pre-dating it, and Henry Highton's 'gold-leaf' telegraph in 1846.W H Hatcher's Double Index Telegraph 1848 Worked by two keys and two induction machines, the indices moved in opposite directions on the dial W H Hatcher, the Company's first secretary and engineer, patented several telegraph instruments in 1847. His double-index machine, with two separately moving hands, was used on the South Devon Railway's circuits in the early 1850s to manage the air pumps that propelled its trains, before the line was put in circuit with the rest of the country. The indices revolved in opposite directions; for train management "they could indicate at all the stations on a single line the progressive movement of two trains running in opposite directions". It was worked by a current-reversing induction machine and small batteries of cells. Hatcher's apparatus was also used experimentally for "working with the code of signals in use by the Admiralty". The Company eventually bought Nott & Gamble's and Brett & Little's improvements in telegraphs in 1849-50 after fighting to convince the Courts that they were infringements of their patents.
Siemens & Halske's earliest American Telegraph 1855 In replacement of the Bain chemical writer on its long-distant domestic circuits in the late 1850s the Electric introduced the American register, manufactured by Siemens, initially with an "embosser", then with an ink siphon to indicate signals on a clockwork-driven paper tape, worked with a sending key. Although less sensitive, requiring more galvanic cells in its operation, than the Bain printer the American telegraph also used a single-wire circuit so was a straightforward substitution of equipment. Electric Telegraph Company - Telegraph Instruments 1860 .....................Two
Needle ....Single Needle .......Printer From
a confidential report from Mark Huish to Robert Grimston,
chairman of the Electric Telegraph Company, October 1860
The Company's hostility to S F B Morse and his claims was such that it retained Bain code until it opened its circuits to the Continent in June 1853. It then adopted what it termed the "European Alphabet", the Continental dot-and-dash code with its diacritical marks, for all of its printers, both Bain's and the American telegraph, and for the single-needle instrument. For the latter a left movement of the needle equalled a dot, a right movement a dash. The first use of the American telegraph in public service in England was in 1853 when it replaced the two-needle instrument on the International Telegraph Company's circuit between London and Amsterdam so as to conform to continental practice. Bakewell's Copying Telegraph 1850 Frederick Bakewell's copying telegraph, developed between 1848 and 1851 and tested by the Company, had manuscript writing or a drawing in varnish on tinfoil applied to a rotating cylinder six inches in diameter and about twelve inches long propelled by carefully-governed clockwork rotating at 30 revolutions a minute. A moving electric feeler on a long parallel screw "scanned" the foil differentiating between the metallic and varnished portions. The receiver was identical but the drum had a dampened sheet of sensitised paper on it and the metallic feeler passed the current through it, marking it in facsimile of the varnish writing. A facsimile of a foil manuscript with 400 characters was distantly copied in two minutes over fifty miles by the Company in April 1851 from the Electric's Central Station at Founders' Court, London to the York Hotel in Brighton. Several facsimiles were sent back and forth, messages were written in full, with capitals and punctuation. It was noted that abbreviations and shorthand could also be used. Bakewell's copying telegraph also successfully transmitted autograph copies of writing a distance of 600 miles there and back between Paris and Nantes, in France, in February 1857. Images transmitted by Bakewell's Copying Telegraph in November 1850 The Electric experimented in 1854 with the system devised by the Rev Robert Walker, professor of physics at Oxford University, to transmit signals in both directions simultaneously on one wire. The world had to wait until the 1870s for Joseph Stearns in America to successfully introduce similar duplex telegraphy. In 1854 Cromwell Varley patented his double current system, which comprised a double-current key and polarised relays. This overcame the significant time-delay in signals using the single-current or American system in underwater and underground telegraphy. It could send twenty-five words with 300 current reversals in a minute, receiving on the American telegraph. The system was first introduced into the Company's long-lines from London to Manchester and Edinburgh in 1854 and to the Holland cables in 1855. Another advantage was in the reduced need for current; only four Daniell cells were required for the Manchester line. It was soon adopted on all of its inland lines using the American telegraph, saving on costs and increasing efficiency. Varley double-current key 1853 Varley's 'translator' of 1855, an automatic system of
batteries and relays or repeaters was introduced for point-to-point
working with the American telegraph, the key-and-inker, between London
and Amsterdam, and then between London and Berlin and eventually to St
Petersburg in Russia. This permitted through working without
transcription. The longest direct line from London to Odessa, by way of
Amsterdam, Hanover, Berlin, Königsberg, Riga, St Petersburg and Moscow,
was worked from 1858 with thirteen Varley translators at five to six
words a minute. This line was often used by the Company to publicise
its reach. The Varley apparatus used in the International Telegraph
Company's circuits from London to The Hague in 1855 comprised an
American 'register' or embosser, two relays, a spacing instrument, two
switches, a galvanometer and a key. This could be used at either end as
a terminal or as a pair as an intermediate translating device. It was
so designed to be used with the Company's double current circuits and
with European single current circuits interchangeably. The terminal
clerks in the longest point-to-point direct circuits had no involvement
or even awareness of the introduction of Varley's equipment in their
working. The original American relay used in long Continental
circuits required continual adjustment due to the "natural" variations
in current as batteries changed and conditions affected the state of
insulation. Varley's relays on the American telegraph were adjusted
just once each day as they were brought into circuit. As already
mentioned, commencing in 1853 the Electric had begun purchasing
American telegraphs from Siemens & Halske. By the mid-1850s these
were sensitive inkers worked with local circuits and relays rather than
the crude 'registers' used in the United States. During 1857 the
Company encouraged two Swiss telegraph engineers, Franz and Meinrad
Wendel Theiler of Einseideln, in devising an even more sensitive
receiver that so reduced friction in the mechanism that the local
circuit and relay of the American telegraph were made redundant. M W
Theiler patented the direct printing telegraph in
Britain in September 1857, the Electric company acquired the rights for
£500 and immediately bought eight instruments for use on its long
lines. Subsequently Breguet purchased the rights for France in
1858. M W Theiler settled in England and, with his sons, began
manufacturing his receiver and other telegraph equipment for the
Company. In the twelve years subsequent to the formation of the Electric company Charles Wheatstone had been seriously occupied at King's College; so much so that he was able simultaneously to introduce, on June 2, 1858, the second generation technology of public electric telegraphy, the automatic telegraph, and the revolutionary means to pass the benefits of telegraphy on to the individual, the Universal telegraph.
Wheatstone's Automatic Telegraph 1868 The Electric company acquired the licence for Wheatstone's automatic telegraph and introduced it on its long-line between London and Newcastle in July 1867, where it was in constant action transmitting from sixty to a hundred words a minute. Henceforth the Company used it on its busiest long-distance circuits. No other company could handle bulk traffic so effectively. This instrument maximised the usage of single circuits by allowing a constant feed of messages on punched-tape into the sender; at the other end the receiver recorded the code on another paper tape, in almost a continuous process. It had three components: the perforator, of which there were several, to enable fast message entry on paper tape; an automatic transmitter through which the punched tape was run at speed to transmit the code; and an automatic receiver, that inked the code onto plain paper tape. Long strips of paper were fed through a perforating instrument with three keys (dot, dash and space) constructed so that the holes controlled the reversal of the current in the manner of a card on a Jacquard loom to generate letters of the alphabet and other signs. The paper strip was placed in the transmitting instrument which on being set in motion moved it along and caused it to act on two pins in such a manner that when one of them was elevated the current was transmitted in one direction and when the other was elevated it was transmitted in the opposite direction. The elevations and depressions of the pins were governed by the holes and intervening paper. The receiving instrument or printing apparatus had two pens or inkers worked by electro-magnets so arranged that when the current flowed in one direction one pen was depressed onto a moving strip of paper and when in the opposite direction the other pen was depressed. The pins of the transmitter and the pens of the receiver could lift back with springs, permanent magnets or electro-magnets. The transmitter and receiver were driven synchronously by carefully-governed clock work. The patent also allowed the transmitter and its perforated tape to work a single-needle or double-needle telegraph. The fourth instrument was an independent so-called 'translator' that allowed an operator to quickly imprint up to 30 different letters, numerals or symbols on to a moving paper tape by using permutations of just eight keys and a space button. This was not a telegraphic device but a simple typewriter; it was not worked in public service. In 1860 Wheatstone amended the automatic telegraph to send and receive messages without using current reversal so as to work with the Electric's newly-introduced Siemens inker-writers rather than his own more complex receivers. About ten per cent of the Company's instruments were inkers by 1868. The original Wheatstone automatic telegraph of 1858 gave an increase in message transmission performance of a factor of five over the single needle and key-and-writer apparatus. R S Culley, the Company's engineer, accelerated the perforating process and eliminated mechanical resistance by introducing a pneumatic three-key punch with piston valves during 1867. This allowed women clerks to perforate tapes for the automatic telegraph with ease. The air came from the reservoirs that worked the Company's inter-office pneumatic message tubes.
Codes of the Electric Telegraph Company Single Needle Bain The overwhelming bulk of its apparatus continued to be Cooke & Wheatstone's single-needle telegraph worked by a drop-handle, slightly modified latterly to place a small angled wooden shelf just below the dial for the clerk to place and read message forms for transmission. It is hinted in several sources that clerks using the single-needle device received messages acoustically as they were able to differentiate the tones of 'right' and 'left' signals as the needle struck its stop pins. C W Siemens observed that the instrument clerks worked their telegraphs with the left hand and wrote down messages with the right hand. During the mid-1850s the Company introduced the desk-top Umschalter, the first switchboard, in replacement for the mass of turnplates for switching. This device, also called at the time the Swiss commutator or current director, was used in major towns to connect local with trunk lines and with other local lines. It consisted of an elaborate peg-board of crossed copper strips, insulated from each other and connected as required by a copper spring-peg through holes at their overlaps. It could rapidly change and connect message circuits and manage internal battery circuits. Although often termed the Swiss commutator the "umschalter" was devised by Ing F W Nottebohm, technical director of the königlich preussischen Telegraphen-Direktion in Berlin. The Umschalter or switchboard was reportedly
adopted by the Electric Telegraph Company in 1854. It was used to connect local
lines at principal stations and to connect local lines to long lines at the
transmission stations of London, Leeds, Manchester and York. Rotary switches
continued to be used to connect long lines. The use of the Umschalter or switchboard
for public telegraph circuits was abandoned immediately the Post Office took
over, not to be reintroduced until 1904. Electric Telegraph Company "Umschalter" 1860 One of the largest "Umschalter" switches was installed at the transmission station in York in 1860. "It consisted of a vertical board, having secured to it twelve parallel horizontal bars and twelve vertical ones. By metal plugs any vertical bar can be placed in contact with any horizontal bar". Twelve single-wire circuits could thus be selectively connected. Previously a Turnplate or rotary switch had been used to connect multiple circuits. That at Normanton transmission station in 1857 was able to select from four two-wire circuits. By rotating a milled knob the clerk was able to make connections by quarter-turns. A smaller version switched between two two-wire circuits by half-turns.S Alfred Varley's chronopher apparatus was controlled by a clockwork-driven conical pendulum and was used from 1852 by the Electric Telegraph Company and the railway companies to send time signals from Greenwich Observatory to some 1,000 towns and railway stations. The time current was received at 1 pm each day, when ordinary message traffic paused, on the single-needle telegraph. The great clock at the Houses of Parliament and its bell, Big Ben, was also controlled by the chronopher. The Chronopher and a Bain Clock The Electric company devised a special "arrangement" in 1852 by which a weighted ring, released by a single electric trip, dropped to close ten time circuits simultaneously. It was entirely enclosed in a glass dome. S A Varley, brother of Cromwell, had previously improved the insulation of the Company's overhead lines by introducing soldering of wire joints in 1852, in place of mechanical or wound joints in the iron wire. He was employed by the Company from 1852 to 1861. Cromwell Varley and his son devised a Fault-finder in 1859. This was an extremely sensitive needle galvanometer between the astatic-pair of which were jaws in which an insulated wire was placed. Previously faults were discovered by pricking the insulation with a pin to obtain a contact for the detector!The Electric company continually reviewed its technology: in 1858 it tested David Hughes' type-printing telegraph. This was in its earliest stage of development and was, unfortunately, rejected as unreliable. The later version was far superior but the opportunity had been lost. It experimented with G Caselli's "pantographic telegraph" or pantélégraphe, a copying device, and P A J Dujardin's type-printing telegraph, a competitor to the Hughes apparatus, in the mid-1860s. The five-foot tall, cast-iron-framed pantélégraphe was tried between London and Liverpool in January 1864 and the Dujardin printer was used for a short period between London and Edinburgh in 1865. The Company found both instruments unsatisfactory for public use, the Caselli facsimile telegraph was slow and difficult to synchronise, and there proved no public demand for it. In its final years it also tried the simple American key-and-sounder working the "European Alphabet" acoustically. Wireless in 1862
Haworth's Wireless Telegraph Apparatus 1862 In the 'Electrician' magazine of February 27, 1863, Varley wrote: "Mr Haworth paid me [a] visit a short time ago, when I asked him if he had any objection to his invention being tested by actual experiment: he said he had not, and pointed out to me how to arrange the various parts of the apparatus. I have preserved the pencil sketch made at the time, as indicated and approved by him. This was strictly followed in the experiments." "The apparatus used was constructed especially for this purpose. The primary coils were thoroughly insulated with gutta-percha, the secondary coils by means of a resinous compound and india-rubber. The plates of copper and zinc at each station were but an inch and a half from each other; they were each six inches square. The two stations were only eight yards apart." "The apparatus at each station consisted of a plate of copper and a plate of zinc, connected to a flat secondary coil containing nearly a mile of No 35 copper wire. The secondary coil was placed immediately behind the plates, and behind this was placed a flat primary coil." "At the sending station the primary coil was connected with six cells of Grove's battery, and contact intermitted. At the receiving station the primary coil was connected with one of Thomson's reflecting galvanometers, of small resistance, no more than that of an ordinary telegraph instrument". "With this disposition of apparatus no current could be obtained." "To account for Mr Haworth's assertions that he has worked from Ireland to London, and between other distant places, I can only suppose that he has mistaken some irregularity in the currents generated by his copper and zinc plates for signals." "If he can telegraph without wires, why does he not connect England with America, when he can earn £1,000 per diem forthwith, and confer upon the world a great blessing?" However in a subsequent issue of the 'Electrician', dated March 6, 1863, J M Holt responded to Varley: "I have seen Mr Haworth's apparatus at work repeatedly, and have myself read off from the indicator the messages which have arrived; and these 'irregular currents mistaken for signals' have consisted of words and sentences transmitted as correctly as by the electric telegraph. My house has been one station, and Brighton, or Kingstown in Ireland, the other." On October 30, 1863 Haworth patented an improved model of his wireless telegraph.J J Fahie, from whose book 'A History of Wireless Telegraphy, 1838-1899' these extracts are drawn, added "After this we hear nothing more of Mr Haworth." Water & AirThe Company's pioneer underwater cable across the estuary of the Tay river in Scotland consisted of three relatively light single-cored cables bound together as one; its companion across the Firth of Forth similarly consisted of four single-cored cables laid as one. The Isle of Wight circuit was a four-cored cable; that to the Isle of Man was a single-cored cable. The Firth of Forth cable from Granton to Burntisland was marked by five green buoys to prevent damage by ships' anchors. The Company's four initial marine cables from Orfordness to Scheveningen on the Continent, actually owned by the International Telegraph Company, of 1853 were laid with single circuits in relatively light armour, the single core being covered with double coats of gutta-percha and cotton tape and yarn, armoured with No 8 BWG galvanised iron wire, weighing two tons a mile. The four cables were joined together as one at the marine league, three miles off the English and Dutch coasts for protection against ship anchors. The Gutta-Percha Company and R S Newall, makers of the very first underwater circuits, manufactured the cables. The Company laid them using its own vessel, equipment and crew, as it did with its all of its domestic and later foreign underwater cables. The Company's original cables were replaced in 1858 by a single cable, comprising four copper cores of No 13 gauge covered with gutta-percha up to No O gauge and armoured with No OO gauge iron wire, between Orfordness and Zandvoort for Haarlem. This was a very heavy and strong cable weighing over nine tons to the mile, manufactured by the Gutta-Percha Company and armoured by Glass, Elliot & Co. Four years later an identically armoured four-core cable was laid by the Company between Lowestoft and Zandvoort. The Holyhead to Howth cables failed in 1859 and were replaced in 1861. This was to be a single-cored lightweight circuit of two tons to the mile, running seventy- six miles from Howth to Rhosneigr on the "mainland" of Anglesey, avoiding the shipping traffic to Holyhead. It was done on the cheap, the cable was that salvaged from its original Dutch circuits. Being lightly armoured it failed several times in subsequent years, finally expiring in 1865. The Company then gave up on the Dublin route and laid a heavyweight cable, larger even than those on its Holland route, from near Port Patrick in Scotland to Whitehead in Ulster in July 1866; it had six cores, weighing ten tons to the mile. To secure its traffic to Ireland and to access the posited Atlantic telegraph the Company also sponsored a new cable to Waterford in southern Ireland during 1862.Latimer Clark's Patent Air and Vacuum Message Tube 1853 Latimer Clark's patent of January 28, 1854 gave a description of his "Apparatus for Conveying Letters or Parcels between Places by the Pressure of Air and Vacuum". These are edited highlights: "The apparatus has a tube extending from one station to another, having branches communicating with vacuous receivers; the branches are provided with stop- cocks. The receivers have pipes communicating with the tube which connects the receivers together, and also with the vacuous reservoir which has a pipe in connexion with an exhaust apparatus. The vacuous reservoir is very similar to an ordinary gas holder, and is in like manner provided with counter- balance weights, pulleys, and chains." The mode of working was as follows: "The letters to be forwarded from one place to another are placed in a capsule or holder filling the tube, which is then deposited within the open end of the tube. An electric signal is then made to the distant receiving station, and the attendant having closed the tube by a slide or valve opens communication between the tube and the vacuous receiver by means of a stop-cock, having by the same operation closed the stop-cock to the vacuous reservoir in consequence of their both being connected by cranks and levers, so that by the opening of the receiver stop-cock the reservoir stop-cock is closed, and vice versa, the capsule containing the letters will be propelled by the pressure of the atmosphere to the receiving station, where it may be removed. The capsule or carrier, which may be made of leather or other suitable material, is surrounded by an expanding valve, so as to exclude the passage of air." "The capsule may be removed from the pipe by opening the upper half of that part of the pipe, which is hinged and fitted air-tight for that purpose, and contains a perforated diaphragm, which may be raised or lowered at pleasure, its rod, passing through a stuffing-box. The perforated diaphragm is only closed at that station at which the capsule and its contents are desired to be retained, and is at all other times raised. The capsule being thereby stopped, the valve is again closed, and the capsule removed, by opening the moveable portion of the pipe as described." "It is obvious that by this arrangement the capsule may be caused to travel in either direction by closing either one or other of the stops." In actuality the operation seems somewhat different.The cylindrical message-carriers were of gutta-percha resin covered in felt, 5 inches long by 1½ inches diameter, small bundles of up to eight message forms were pushed into the hollow core at the branch office. The carrier was placed in the open mouth of the tube and an electric bell rung at the main station, the pipe connected by a simple valve to the vacuum chamber and atmospheric pressure propelled the carrier to a vertical tube-station in the gallery where a spring buffer immediately cut off the vacuum and the carrier dropped out through a trap-door onto a counter. The carriers were calculated to travel at 40 miles per hour. There were five pneumatic tubes at Telegraph Street; four external "circuits" for messages to and from the stations at Founders' Court, Cornhill, Stock Exchange and Mincing Lane; and one inter-departmental "circuit" used for messages and documents in 1864. The total reached seven external and five in-house tubes during 1868, with a larger 2¼ inch pipe being introduced transmitting twenty messages in one carrier. The new "air circuits" led to the offices of the Atlantic and Indian cable companies. A larger 40 hp steam engine was also installed. In Latimer Clark's system only vacuum was used to propel the carriers. It was thought that the use of compressed air would fail as it expanded and became less effective towards the end of the tube. In 1858 it was proposed to connect the new Central office with the Strand and several other busy stations with large-bore, 2¼ inch diameter carrier tubes. Latimer Clark advised the laying of a parallel second 1½ inch tube to provide vacuum at the distant station allowing to-and-fro traffic in the large one. The secondary tube was first applied parallel to the large bore tube between Founders' Court and Mincing Lane during 1858 but its capacity was discovered to be inadequate for the traffic. A vacuum chamber of 1,680 cubic feet was then constructed in a basement adjacent to the Mincing Lane telegraph office, continuously evacuated by the 1½ inch pipe, to act on the 2¼ inch tube. The experiment came to an end when one of the carriers stuck in the large tube and the continuous vacuum rose to such a level that the chamber collapsed, drawing into its void the owner of the house, his kitchen furniture and the glass of most of the windows of the neighbourhood. When Cromwell Varley became engineer as well as electrician to the Company in 1860 he took up the scheme to connect the Central station with Mincing Lane, Cornhill, the Royal Exchange and Founders' Court with two-way air circuits. To achieve this he introduced compressed air in addition to the vacuum in each tube controlled by an ingenious set of self-acting valves. In Latimer Clark's original system the operator at Founder's Court had to manually open and close two valves or cocks to receive a carrier on receiving an electric bell signal from the farther end. This meant that he could only manage two air circuits at one time. Varley caused the vacuum and the compressed air to work the series of valves and cocks merely by pressure on three spring-loaded mechanical buttons or miniature valves. The "Receive" button opened the vacuum to two small cylinders; one closed the door of the tube, the other opened the main valve between the vacuum reservoir and the tube, which stayed open on a detent. As the carrier arrived it struck a rubber buffer that worked a third cylinder that released the detent to cut off the vacuum in the main tube, allowed the end door to open and the carrier to fall out by gravity. The valve attached to the "Send" button, once the message carrier had been placed in the tube, opened the compressed air reservoir to close and lock the end door of the tube, and then at the end of its travel opened a second valve allowing compressed air into the main tube. Once the carrier had arrived at the far end the electric bell was rung and the "Cut-off" button was pressed which used the compressed air to close the main valve to the tube and to unlock the end door ready for the next carrier. The sophisticated and ingenious mechanism
of the air valves was manufactured for Varley by F G Underhay, a sanitary
engineer and brass founder, of Clerkenwell.
Before two-way working was introduced the message-carriers were returned by hand in bags.
Varley's Improved Pneumatic Tube 1870
Varley's Improved Pneumatic Tube 1870
The five internal tubes connecting Telegraph Street's principal Instrument Gallery with the Atlantic cable office, the Indo-European office, the Engineer’s office, the South Instrument Gallery, and the Intelligence Department In 1871, to the Institution of Civil Engineers, Varley stated "It was found that the saving in expense, by the number of clerks' salaries dispensed with, was considerably more than the total expenditure of working the engines and the interest upon the capital expended in putting down the pipes." A wire could carry just one message at a time whilst the 2¼ inch tube carried fifteen messages in a single carrier. Over the distance of 1,340 yards between Telegraph Street and Mincing Lane the tube was therefore equal to fifteen wires; each wire would require one sending and one or two receiving clerks. On this "line" the carriers took 60 to 70 seconds by vacuum and 50 or 55 seconds by compression to complete their journey. The outer iron pipes originally had screw-joints which proved leaky and allowed water to be drawn in by the vacuum. The screw-ends were eventually cut out and the joints all soldered. Problems also occurred with the carriers, although the lead-line tubes caused little wear. Thin metallic tubes were tried but were too easily crushed before gutta-percha resin covered with felt was settled upon. Even so if the felt did wear friction could cause the gutta-percha to melt and stick to the tube. The end cap also blew off from internal air pressure when entering the vacuum, eventually a rubber band replaced the cap. A long 2¼ inch two-way air circuit was planned between Telegraph Street and the Strand, with an intermediate station at Fleet Street, but as there were already two or three telegraph companies working over the route the Electric decided not to proceed with the work. The air also powered the perforator or tape-punching apparatus of the Wheatstone automatic telegraph, speeding up the keying of messages immeasurably. The mechanism for this was introduced by R S Culley, the Company's engineer, in 1868. The use of pneumatic and atmospheric transmission
of power dates well before the advent of the electric telegraph. In 1827 John
Hague of Wellclose Square, London, had patented atmospherically-worked cranes,
hammers and engines. The connection between Samuda & Clegg, the patentees in
1838 of the most-used system of atmospheric propulsion on railways, and the
telegraph in the 1840s is very well-known. However, the compendious patent for
atmospherically-driven machinery acquired by Thomas Clarke, engineer, of Hackney,
and John Varley, engineer, of Poplar, of February 1846, which included a
railway, a ploughing machine, a pile-driving machine, excavating machines, a stone-cutting
machine, a stamping mill and a wharf crane, is relatively unknown. The huge coincidence
of the family names of Clarke and Varley in this and the subsequent development
of pneumatic and atmospheric tubes by Latimer Clarke and Cromwell Fleetwood Varley
for the Electric Telegraph Company, seems to be just that - a coincidence. The steam engine for the air pump in the
basement at Telegraph Street additionally drove a “lathe” for mechanically
cutting paper strips to form the paper tapes used in the printers of the
Company’s American and Automatic telegraphs. Cooke & Wheatstone's two-needle telegraph b.] The British Electric Telegraph Company Highton's Single-Needle Code 1853 Highton's
alphabet or code was remarkably efficient; being "made up in the
following manner: twice to the right, or 33, signifies A; twice to the
left, once to the right, and once to the left, or 1131 = B; 311 = C;
133 = D; a single signal to the left, or 1 = E; thus acting on the
correct principle of representing the letters of most frequent
occurrence by the most rapidly executed signals; F 313, G 1133, H 113,1
31, J 3133, К 1331, L 331, M 1113, N 13,0 11, P 1111, Q 1313, R 333, S
111, T 3, U 131, V 1311, W 1333, X 3113, Y 3111, Z 3131. A motion to
the left signifies 'Do understand,' and one to the right 'Not
understand.' 'Repeat' is expressed by 3331, and 'Wait' by 3333." This
was said to be a great improvement on that devised by W F Cooke in
which left and right movements of the needle corresponded "in some
arbitrary way with their order in the alphabet".
Unlike other systems Highton's evolved over a period of several years. The horseshoe magnets were patented in 1848, when they were worked with two wires by rotating commutators. It was in his patent of 1850 that Edward Highton introduced current reversal and single wire working, and the tappers were patented in 1852. The Company's iron wires were suspended from poles using Highton's patent gutta-percha insulator; in this a silk ribbon was wrapped about the wire for about sixteen inches and covered by hot gutta-percha in a horizontal cone shape. When this remarkably elaborate arrangement cooled to a solid it was screwed onto the pole or cross-bar and varnished. Another variant had cylindrical fillets of gutta-percha inserted through the poles. It also used Highton's rather more effective patent "bead" insulator, a pierced glass sphere inserted directly into the body of or stapled on to the shaft of the pole or pinned to a supporting arm. Highton patented the cross-bar or horizontal supporting arm for carrying insulators on pole telegraphs in 1848 and X-arms in 1852.
Highton's Glass Bead Insulators (above) and The six-core cable was manufactured by the Gutta Percha Company of London and armoured and laid by R S Newall & Company of Gateshead to the same pattern as that used by the Magnetic company in their Irish cable of 1853. The steamer Monarch, chartered from the International Telegraph Company by R S Newall, accom-panied by the tugs Wizard and Conqueror, successfully laid the twenty-seven mile cable from Port Patrick to Whitehead, near to Donaghadee. To connect with its domestic network the British Telegraph Company laid an underground circuit from Whitehead to Carrickfergus for Belfast, and another to Stranraer and Ayr for Glasgow in 1855. The connection to Dumfries for London was not completed until March 1855. It used Highton’s single needle telegraph in its circuits.
The Highton single-needle telegraph was also used successfully on the
underground circuits of the European & American Telegraph Company
when it merged with the British concern in 1854. Edward Highton was a director of the Company until its merger. His tappers were in use in public telegraphy for over seventy-five years. c.] The English & Irish Magnetic Telegraph Company Henley's Magneto-Electric Telegraph 1851 Henley's original large magneto telegraph 1851 As described by William Thomson in 1860: Henley's telegraph "consists of a double or single magneto-electric machine, sending through two line wires, or only one, to a double-needle or single-needle receiving apparatus, which consists of electro-magnets, with steel needles movable through small angles across the lines of force between their poles. There is no commutator and no breaking of the circuit in the sending machine; but a single motion of a key, when pressed down by the operator, produces an electro-motive impulse, which sends a current through the line; and the return motion of the key, rising by a spring, produces subsequently a reverse impulse and a reverse current. Under influence of the first, or direct current, as we may call it, the receiving-needle moves from a stop, on which it rests during cessations of action, and strikes another placed to limit its motion. On this second stop it rests until the reverse current brings it smartly back to its normal position. The resting of the needle firmly on either stop is secured by the magnetic force exerted between itself and the soft iron of the electro-magnet." "In the double-needle system of the magnetic telegraph, a single motion and return of either needle constitutes a simple signal; and the alphabet is composed out of two simple signals, ... positive and negative. In the single-needle magnetic system, the operator works precisely as with a ... key, and he thus produces short and long deflections, since the needle rests deflected against its limiting stop until the reverse current brings it back; and the alphabet is composed... out of two simple signals, the short or dot, and the long or dash." Henley’s Two-Needle Code 1851 Understand R Not
Understand L L = Left, R = Right, V = Together The Company’s clerks, according to Bright, received messages on the magneto- electric telegraph acoustically as the left and right needles struck pins with slightly differing tones. The principal disadvantage of the magneto-electric telegraph was the need for a two-wire circuit. Its main circuits were insulated with resin and buried underground in Henley's patent protective troughs. It had tried unprotected gutta-percha insulated wire on its first circuit between Manchester and Liverpool in 1851 but this failed almost immediately and was replaced by a resin-insulated line in troughs. Bright's Improved Magneto Telegraph 1855 Altering the action of Henley's original by replacing the short acting levers with long-stroke handles, and the use of large horseshoe magnets Charles Tilston Bright, who had worked for both the Electric and British Telegraph companies, replaced W T Henley as engineer to the Magnetic company in 1852 and made substantial modifications and additions to Henley's system. He had a comprehensive patent in 1852 covering improvements to Henley's magneto telegraph - replacing his short-acting levers with more robust rotating handles, a new very efficient overhead insulator and several varieties of troughs for protecting underground circuits. Bright was then age 20. Its underground circuits of 1852-3 in England and Ireland were created to Henley's plans. For its main city-to-city circuits ten insulated wires were laid in troughs of grooved boarding, covered either with wooden or iron lids. Each copper wire was of No 16 BWG insulated with gutta-percha to No 3 BWG thickness by the Gutta-Percha Company, served over with two thicknesses of jute and Stockholm tar, and laid in the troughs in two rows to a depth of two feet. There were testing boxes every three miles. Henley's Cast Iron Split Pipe for Telegraph Cables 1853 Under busy streets of towns from 1852 the Company used cast-iron split-pipes of Henley's patent design each of six feet length with a two-inch bore, the metal 3/8 inch thick. The top and halves were secured together by two pairs of lugs and small nuts and bolts. Similar split-pipes to Henley's patent, whether round or square in section, were to be adopted by all the other companies except the Electric. The cost of laying six wires in troughs or pipes along the mail roads was from £180 to £200 a mile; for ten wires the cost went up to £230 a mile. The overhead lines that it built, mainly in
Ireland, were on round larch poles with insulation for the No 8 gauge
iron wires originally formed, after Henley's plan, from small cylinders
of gutta-percha, called by the inventor "thimbles". The resin tubes
were speedily replaced in 1852 by large earthenware insulators designed
by C T Bright. The Magnetic allowed only eight wires to be attached to
each pole. R S Newall returned to Port Patrick with the Britannia in June 1854 and, overcoming immense difficulties, recovered the sixteen miles of old cable over a period of four days. It was found on testing to be electrically sound. The Magnetic company finally made its connection between Port Patrick, Scotland, and Donaghadee, Ireland, on its second attempt, during May 23, 1853. The six-core cable was once again manufactured by the Gutta Percha Company and R S Newall. Newall also contracted to lay the cable. His steamer William Hutt was accompanied by the tugs Conqueror and Wizard acting as guard boats, and successfully laid down the twenty-four miles of cable from a point two miles south of Donaghadee to Mora Bay, a little to the north of Port Patrick. It cost £13,000 to complete. The cable specification allowed for six copper conducting wires of No 16 gauge insulated with gutta-percha resin, supported by hemp cords, all surrounded by a serving of tarred hemp spirally twisted around the cores. This was protected or armoured by ten No 1 gauge iron wires galvanised with zinc to resist corrosion, spirally wound around the whole. It weighed seven tons to the mile. The cable was based on Thomas Crampton’s design for the successful cable across the Channel in 1851. An identical specification was used in the British Telegraph Company’s Irish cable of 1854. The Magnetic company also was constructing an underground roadside six-core circuit from Carlisle to Dumfries and Port Patrick in May 1853, to connect the cable with the rest of England and Scotland. d.] The European & American Electric Type-printing Telegraph Company
Jacob Brett's Printing Electric Telegraph 1850 The Submarine Telegraph Company, which also tried Brett's patents, made some extravagant claims for this sophisticated apparatus in January 1850, "The telegraph shall, by the aid of a single wire and two persons only (the one stationed in France and the other in England) be capable of printing, in clear Roman type (on paper) one hundred messages of fifteen words each, including addresses and signatures, all ready for delivery in one hundred consecutive minutes". In the event the Brett apparatus was inreliable and the Submarine and European companies both used Cooke & Wheatstone's two-needle telegraph to work their earliest circuits. The original Brett-House telegraph consisted of two elements, the compositor (sender) and the printer (receiver). The compositor mechanism had a keyboard like a miniature piano with twenty-eight keys, beneath which was a rotating cylinder with a spiral of twenty-eight small pins along its length, on the end was a wheel or circular commutator or switch that opened and closed a circuit twenty-eight times in one rotation. The cylinder was kept revolving by a weight and pulley, with a speed governor, sending a series of electrical pulses. Pressing a key stopped the cylinder at one of the pins and broke the circuit. The printer possessed a small type-wheel with twenty-eight characters engraved on its periphery, an abbreviated alphabet, a dot and a space, also revolved by a weight and pulley. Beneath it were two large vertical electro-magnets that created a to-and-fro motion, regulated by a so-called hydraulic governor. The opening and closing of the circuit by the compositor caused the electro-magnets in the printer to allow the type-wheel to rotate in precise sympathy with the cylinder beneath the keyboard. As a key was pressed, the cylinder stopped, the circuit was broken and the type-wheel stopped at the same moment, at a particular letter. The wheelwork rotating the type-wheel was then applied to eccentrics that moved a paper tape one space and pressed it firmly against the type-wheel, which was kept 'inked' by a hollow-roller filled with powdered plumbago (graphite). As the current was restored when the sending key was released and allowing the compositor cylinder to rotate, small springs lifted off the paper tape and the type-wheel continued to turn. Both compositor and printer relied on clockwork-generated energy to turn their separate rotating elements; electricity merely regulated the rotation. An initial key press set off an alarm bell perched on the top of the apparatus after which the instruments at either end had to be put in synchronisation before the message might be sent. In appearance the Brett-House telegraph had a tall pierced or skeleton brass framework containing the printer, with a bell mechanism at the head, fitted to a mahogany stand in which the compositor and its keyboard was set. There was also a large clock-like dial in the centre brass framework that indicated the letters of the alphabet by means of a rotating hand. It was, of course, a very complex and expensive apparatus compared with the needle telegraph; its chief advantage was its sending speed, printing alphabet on tape twice as fast as the needle competition could be read. This was the original electro-magnetic version of the House telegraph devised in 1844 not the particularly elegant electro-pneumatic version widely used in the United States from 1850. Royal House's successful electric type-printing telegraph preceded the mechanical office typewriter by thirty years. The European company also experimented with G E Dering's single pendulum needle telegraph on its circuit between London and Dover for a short period. The 'Builder' magazine in November 1852 described the European company's original circuits, "The line of telegraph of which we are speaking consists of six pure copper wires encased in gutta percha. These wires are manufactured in half mile lengths, which (after being joined together) are protected along the high roads by wooden troughs, and in towns by iron tubes, which are respectively sunk to an average depth of two feet beneath the surface of the ground. The troughs are of simple construction, being formed by sawing a deal into three, thus obtaining a square of about 2¾ inches, with a groove cut out at the planing mills, to contain the wires. The ends as well as the tops (which latter are about three-quarters of an inch in thickness), are cut to a bevel, and so the covering is made complete and secure. In the method of joining the iron tubes, the Company have availed themselves of a patent taken out by Mr Brett; a circular dovetail on the casting of each alternate pipe is inserted into a corresponding aperture left for the purpose in the substance of the tube next adjoining it, and so on. The Company, foreseeing the possibility of injury to their wires, have provided at the end of each mile, a box, in which the continuous line of wire is coiled, for the length of some few yards; so that, should any mischance occur, the means of testing the soundness of the line, mile by mile, are at hand; for all that is requisite in such a contingency will be the severance of the coiled wire at the end of any given mile, and a trial of its efficacy up to that point by means of a portable battery." The seven mile long urban section from the Cornhill telegraph station to New Cross Gate, across London Bridge, was laid under the pavements inside the 2 inch cast-iron pipes by William Reid, the first and largest telegraph contractor in Britain, by September 1852. The rest of the Dover circuit, in
wooden troughs, was speedily laid by the contractors, Frend &
Hamill. The European company's original gutta-percha insulated
underground circuits from London to Dover were not well engineered and
quickly started to fail. W T Henley engaged to take-up its whole
length, replacing the bad parts and re-covering the remainder with a
serving of tarred jute. He did this, without stopping the working of
traffic, during 1855. George Saward, the former secretary of the British Telegraph Company, of which the European company became a component, noted to a Parliamentary enquiry on January 12, 1860 that its long subterranean line between London and Liverpool completed in May 1854 was also of poor quality. Of the six gutta- percha insulated copper wires laid in the troughs one had never worked and the other five failed and required repair within nine months of use. He mentioned that the circuit was worked with the "little" Highton single-needle, double-tapper instrument at twenty words a minute. Thirty-six 24-cell Daniell batteries were initially used, but better performance was achieved by reducing this to twenty-four 24-cell batteries.
e.] The Submarine Telegraph Company John Watkins Brett was the promoter and a director of this Company and of many other overseas cable companies, as well as of the European & American Telegraph Company. His brother, Jacob, was to provide electrical expertise to both companies, as well being patentee of the printing telegraph. Jacob Brett's Type Printer 1851 Jacob Brett's Rotary Transmitter 1851 These two instruments were used on the Submarine Telegraph Company's The "improved" and much modified Brett patent instrument displayed at the Great Exhibition in 1851 and used experimentally on the Channel cable between England and France in that year comprised two separate parts somewhat different in working from the original: there was the basic printing element controlled by either hydraulic or pneumatic regulators, with a signal bell, twelve inches wide by seven inches deep by twelve inches high; with the communicator or sending element opening and closing the circuit, sending pulses of electricity, by means of a rotating handle or hand pointing to a letter on an engraved circular index, in a case four inches by four inches by two inches deep. Three alternatives were shown to the public: a more complex printing element with an additional dial having an index hand for paper-less receiving and bell signals; and a communicator with a piano keyboard, each key representing a letter of the alphabet. There was also a pocket communicator, a miniature rotary device indicating the roman alphabet, for use by guards on railway trains, just three inches by three inches by two inches in size. The pocket apparatus required that a separate electric battery be carried on the locomotive tender; its circuit being made from a small reel of copper wire connected to the line-side overhead iron wire by a long pole, the return being by a connection to the rails. ![]() Jacob Brett's "Portable Telegraphic Communicator In 1858 John Watkins Brett wrote that the patent instrument "incurred a sacrifice on my part of many thousand pounds, without any valuable result for general purposes." William Andrews,
the company's engineer, worked through the late 1850s to develop an
effective current reversing and relay apparatus for underwater cables
to defeat retardation, improving on those introduced by C F Varley and
Siemens Brothers. In essence these worked as the sender or key in
concert with the receiver or inker of the American telegraph. He was
successful in 1860 and his "pneumatic relay", or "pump", as it was
commonly termed, was introduced on the Submarine company's longest
cables from England to Hanover and to Heligoland and Denmark. It had
been developed with the Company's mechanician, James Banks, and the
telegraph instrument makers, John Sandys, R B Jones and Reid Brothers.
Its advantage, in addition to discharging or reversing the current in
cables, was stated to be that the key had an instantaneous descending
and a graduated ascending movement governed by a hydro-pneumatic
device, enabling messages to be interrupted between a letter, word or
sentence. It was first used at the Company's Cromer station in East
Anglia to connect with Heligoland and Flensburg in December 1860, when
eleven instruments were in service. The "pump", then made by S W
Silver, was later adopted on the government's 1863 cables in the
Persian Gulf. Cooke & Wheatstone's Two-Needle Telegraph
The Submarine Telegraph Company's first cable of 1851 was of four
copper conducting wires of No 16 BWG, each insulated with gutta-percha
up to No 2 BWG thickness, "formed into a rope", covered with tarred
hemp and protected or "armoured" with ten iron wires of No 1 gauge. It
weighed six tons to the miles and lasted without substantial repair
until 1859. The Ostend cable of 1853 was of similar construction but
with six cores. Subsequently stranded copper wire was used instead of a
solid single wire. The Hanover cable of 1858 had two stranded cores and
weighed three tons a mile. The Boulogne cable of 1859 had six stranded
cores protected by No 0 gauge iron wire armour and weighed an
exceptional 9½ tons a mile. In the same year the Denmark cable was laid
by way of the island of Heligoland with three strands and weighed four
tons a mile. The Company placed all of its conducting circuits in one
cable. Between October 31 and November 2, 1858 the Company had Glass, Elliot & Company lay its longest cable. The circuit ran from Cromer to Weybourne in East Anglia and then 210 miles to the island of Borkum off the coast of Hanover in Germany, hence to the city of Emden. There were 280 miles of cable; there were two cores each of four No 22 BWG copper wires insulated with gutta percha and Chatterton's preservative compound to No 3 BWG thickness by the Gutta Percha Company and armoured with twelve wrought-iron wires each of No 6 ½ BWG by Glass Elliot. It had taken two months to manufacture; the laying was supervised by the Submarine's engineer, William Andrews, on board the screw steamer William Cory, which was accompanied by the paddle steamer Reliance. From July 11 to July 14, 1859 a new three core circuit was laid in two lengths to Denmark; from Cromer to Heligoland by the William Cory steamer and from Heligoland to Tonning by the Berwick. This, of 328 miles total length, was also manufactured by the Gutta Percha Company and Glass Elliot & Company. The Submarine company saved money when it was compelled to lay a new cable from Beachy Head to Dieppe as part of the renewal of its French concession. It bought the remainder of the six core cable made for the Mediterranean Telegraph Company's unsuccessful line from Cagliari in Sardinia to Bone in Algeria and had W T Henley recondition and then lay it between England and France on June 27, 1861. That was not the end of its parsimony (or economy); when the Hanover cable was abandoned in 1865 much of it was recovered and reconditioned by W T Henley, under sub-contract from the Telegraph Construction & Maintenance Company. Its two cores were combined with newly manufactured stock to make a 47 mile four-core cable that was laid from Dover to La Panne in Belgium during November 1867. f.] The British & Irish Magnetic Telegraph Company
Bright's Bell Telegraph 1856 William Thomson noted in 1860 that "the sound of two bells, struck by the needle or needles, when deflected by two currents (positive and negative) respectively, has been recently put into practice on a very extensive scale, by Sir Charles Bright, with the aid of a simple and effective relay, represented in the annexed figure which he has invented for the purpose, and which proves most successful. This relay, with a local battery supplying the mechanical power required to strike the bells, has been substituted at the principal stations of the British and Irish Magnetic Telegraph Company in England and Scotland, instead of Highton's single needle (which is still retained on their railway circuits, and some of their less important commercial circuits); and ..., that 'for ordinary circuits nothing can work better'; that 'more work can be got from one clerk and one wire by it than by any other receiving instrument;' and that it is gradually being extended to the utmost in the telegraphs of that company. The transmitting instrument used for sending is still Highton's key described above; and it is worked by the staff of operators and clerks trained under Highton's system. The receiving clerk sits between the two bells, and, with only the ear engaged in receiving the signals, writes down his interpretation of their meaning with a degree of ease and accuracy not attainable when one clerk has to watch the needle and dictate his interpretation to another who writes it down, as in receiving by the needle instruments or any other instrument indicating by transient visual signs." Charles Bright's Bell telegraph was the first successful acoustic message telegraph (if one ignores the crude railway bell signals), preceding the American acoustic box-sounder by several years. It was also by far the "fastest" non-automatic telegraph instrument, regularly receiving cypher at over thirty words a minute on the longest circuits, as the operator's hands and eyes were free for message-taking. Highton's Current Reversing Key or "tappers" 1852 By 1862 Henley's magneto-telegraph was in use only on the Magnetic's rural circuits in Ireland. There were none remaining in Britain. William Thomson records in 1860 that "At many of the more important stations Sir C Bright has introduced his bell relay in connection with them [Henley's magneto-telegraph]; the double-needle instrument being made to direct the power of a local battery to strike one bell when a current comes through one of the line wires, and another bell when a current comes through the other wire; and the single-needle instrument being similarly arranged to produce on a single bell a mere blow giving a clear sound, or a blow and sustained pressure producing a muffled sound, according as the short signal (dot) or the long signal (dash) is sent." Henley's magneto-dial telegraph 1861 Although the Submarine company was one of the earliest adopters of the American telegraph in Britain the Magnetic seems not to have used any recording or writing instruments. Neither did it use the switchboard. Regarding its land-lines; as well as continuing to lay resin-insulated wires in Henley's patent horizontally-split cast-iron pipes until the late 1850s the Magnetic also began, as its subterranean gutta-percha insulation failed, to use iron wires suspended from poles on its long-distance lines and adopted C T Bright's very large and very effective double-bell ceramic insulator of 1858, bolted to the top of cross-pieces. Bright's insulators were made, it seems, by John Cliff & Company, Imperial Potteries, Princes Street, Lambeth, London, manufacturers of stoneware for the chemical industry and "white stoneware insulators, pole caps, battery-cases, &c." Cliff's works functioned from 1857 until 1869, when they removed to Runcorn in Cheshire.
Charles Bright's Patent Insulator 1858 The bulk of its resin-insulated subterranean wires were carried in slots machined in creosoted wooden sleepers, 3 inches by 3 inches in section, these were sealed with a 1/8 inch thick galvanised iron lid secured by small iron spikes. They were buried in a trench 24 inches deep. The underground cable was laid in these troughs as they were laid in the trenches from a large diameter wooden drum. These subterranean lines gradually failed, the Company's directors believed, "due to the misdirection of the iron nails used to secure the lids, to the perishing of the gutta-percha through dryness, to the entry of contaminated water and to attack by coal gas leaking from parallel underground pipes." When the Magnetic and British companies merged in 1857 to form the British & Irish Magnetic Telegraph Company, the combined firm possessed two cables connecting Britain and Ireland, from Port Patrick to Donaghadee, with three magneto circuits and six galvanic circuits. This capacity gave the new company a virtual monopoly of traffic to Ireland for several years as the Electric competition then had only two circuits to the city of Dublin.C T Bright was the Magnetic company's engineer until 1860 and a consultant until 1868, whilst his brother Edward was the Company's chief manager throughout. g.] The London District Telegraph Company Tyer's Single Needle Telegraph 1859 A very small instrument adapted from Tyer's railway signal apparatus, with his novel "piston" key, used only on the London District Telegraph Company In its subsidiary private-leased circuits the District used the Siemens Brothers' magneto-electric dial telegraph of 1859. It had tested W T Henley's, Polidor Lippens' and Charles Wheatstone's dial telegraphs before deciding on the Siemens instrument. This device, common on railway circuits in Germany and Russia, indicated the Roman alphabet with a pointer on a small dial using an electrical escapement worked by a communicator handle resting on a second much larger metal dial face, rotating a magneto. The instrument was much larger than Wheatstone's universal telegraph and was used only on the District's circuits.
The District's principal circuits were constructed in radial trunk lines
outwards from a central hub in Cannon Street, with branch lines from
each radial and some cross connections. All of its public messages,
even those for the shortest distances, were routed, with a dedicated
wire for each station, through the central hub. The office in Cannon
Street was also in electrical connection with the Magnetic's chief
station in Threadneedle Street. It was intended to have other hubs
about London as its message business developed but this was never
carried out. Its other circuits until 1866 were
so-called "over-house" open wire lines on poles. The roof-top supports
were novel; being cylindrical, telescopic wrought-iron "poles", stepped
on to the ridge tiles of house roofs and stayed with iron wire ropes.
They were apparently painted to protect them against the elements;
those in the East End of London were described as "elevated garish
green and white poles". They were devised by its electrical engineer, Edward Tyer, in 1860. The short poles, carrying from one to twenty galvanized-iron wires, were secured on house roof-tops at long 300 yard intervals and were said to deface the skyline. Its insulators on these poles were to C T Bright's large ceramic double-bell pattern, as used by the Magnetic company from 1858. These wires proved extremely vulnerable to high-winds, leading to the destruction of much of the network in January 1866. In cities the telegraph companies had threaded their wires through underground conduits beneath the streets, concealing their presence. The District did not, apparently, use any up-to-date switching devices, like the Electric's umschalter, which would have speeded connections and accuracy in its complex circuits, of which eighty entered its principal office from the suburbs. h.] The Universal Private Telegraph Company William Thomson gave this effusive, and wholly independent, review of the Universal telegraph in 1860: "The details of this most pleasing and popular of telegraphic systems have been recently improved with admirable skill and ingenuity by its inventor. In his original [1840] instruments (to use his own words), 'much remained to be done to render them capable of extensive practical application. Increased speed, greater simplicity, and portability of form, and, above all, absolute certainty of action, were required, to give them, with the advantages they possessed, decided superiority over the needle and other signal apparatus in use.' By his improvements patented in 1858, he has 'rendered this telegraph all that is required for practical use, combining certainty, speed, simplicity, durability, and portability.' To avoid as far as possible more massiveness in moving parts than is required for strength, or for mechanical effects to be produced by inertia, an obvious enough principle, too often neglected by instrument-makers, has been the chief object aimed at, so far as the mechanism of these instruments is concerned. The works of a watch or chronometer are more durable and more certain in their action than those of almost any larger machine comparable with it as to complexity, and Mr Wheatstone seems to have been impressed with this idea in designing the beautiful receiving instrument..., along with one form of 'sender,' adapted to work it, which, being electro-magnetic, requires no battery...". "For the uses for which these instruments are chiefly intended, that is to say, for short lines of telegraph, with no specially trained telegraph operators to work them, these instruments seem to be almost perfect. The facility they afford for communication between different offices, departments, or stations of government, of national defences and field operations of an army, of law-courts, and of general, commercial, and manufacturing business establishments, can scarcely be over-estimated. It is to be hoped that, at least in all matters affecting the security of the country, and the efficiency of our army, in any part of the world, they will immediately be taken advantage of to the utmost."![]() The Universal telegraph was mainly used in pairs, connecting just two locations; but subscribers could connect by a separate circuit to a central office in the cities where the Company operated so that messages could be transcribed to and from the public telegraphs. For circuits with several Universal instruments the company used a switch or "current changer" that enabled the clerk to send up or down the line in either direction, without interrupting the communication of those stations situated in an opposite direction to that in which he wished to speak. It allowed several instruments to communicate with each other at the same time by dividing the circuit into independent sections. In such complex arrangements the use of the current changer required each Universal telegraph have its own call sign (as with public telegraph stations) and that it be switched as a through circuit when not in use. The Universal telegraph indicated the full twenty-six letter Roman alphabet, a full–point, a comma, a semi-colon and a cross- or reset-mark. The dial also contained a sub-set of the numbers 1 to 0 with a reset-mark, shown twice for speedier use. The crank was worked with the right hand, the communicator buttons with the left hand. The alarms, used to attract the clerk's attention, were ingeniously designed to work only with the sending of two or three currents or rotations of the crank so as to avoid accidental use. The earliest instruments of between 1859 and 1863 had separate communicator and indicator components; the original communicator dial was of quite large diameter with a belt-drive. The receiving indicator then had a swivelling dial on two small posts with the alarm in the base. It was occasionally called the "coconut" receiver by the press as the dial was contained in a small barrel-shaped wooden body. However the commonest Universal telegraph combined both in one compact polished-mahogany case, of a size 14 inches long by 8 inches wide by 10 inches high, a handsome adornment to any desk. There were also even neater, hand-portable one-piece Universal instruments for field use. These improvements to Wheatstone's original design were made by his employee, the engineer Augustus Stroh. In 1862 Wheatstone demonstrated a new Universal type-printing receiver for private use to be used instead of the indicator dial. In this the rotating index hand was replaced by a brass daisy-wheel with letters and numerals on the petals which were "printed" onto a re-usable tin-foil tape automatically, without the need for attendance. Contained within a discrete printing box; it was opened and the metallic message tape read as and when the recipient desired. In 1867 its engineer, Colin Brodie, was experimenting with switchboards for use at its hub stations in London, Manchester, Newcastle and Glasgow by which the subscribers' Universal telegraphs could be put in circuit with each other, creating local networks.There were three other competitive magneto-electric dial telegraph instruments available in Britain.
The most successful was that developed by
Siemens & Halske in Berlin in 1858, where it was called the magnetzeiger (magneto
indicator or dial), made available to private subscribers by the London
District Telegraph Company. With a large and somewhat clumsy, though thoroughly
effective, construction (it was so large, with a door at the front, that one
wit in Europe dubbed it the “dog kennel”), it does not seem to have been used
outside of the British capital, but over 700 were in use in Russia, Germany,
Turkey and Sweden by 1864. In Siemens instrument the electro-magnet, wound with
insulated wire and placed vertically inside a brass cylinder, was made to
rotate on a vertical axis between the poles of permanent horse-shoe magnets by
a large crank handle. Alternate currents of positive and negative electricity
were generated and transmitted to the distant station, setting in motion an
index-hand by an escapement. A serrated wheel beneath the handle enabled the
operator to stop the handle at any particular letter with greater certainty. It
was both reliable and accurate. Of some importance was the much simpler dial telegraph devised by W T Henley in 1861. Similar in operation to but more compact than that of Siemens & Halske's, this appears to have had technical limitations which affected its acceptance, despite the support of the British & Irish Magnetic Telegraph Company. The so-called Globe telegraph of Henry Wilde, of 1863, a clear imitation of Wheatstone's instrument, appeared too late to be successful in the private wire market. At the 1862 International Exhibition in London the 'performance' of these instruments was compared: Wheatstone's Universal telegraph "worked perfectly" through a circuit of resistance equal to that of about 375 miles of No 8 gauge iron wire, and had previously been tested successfully up to 450 miles, working practically on 100 miles. Siemens magneto-dial worked through 468 miles of No 8 wire and was in regular use on a similar distance between St Petersburg and Moscow in Russia and over 25 miles in Bavaria. Henley's dial worked through 185 miles, and Wilde's Globe magneto could, in its most improved version, work through 140 miles of wire, but its normal small armature, producing the current, limited it to much lesser distances. Apart from that latter negative, Henley's magneto-dial was criticised in that "there is no notched wheel to enable the operator to stop suddenly, and no contrivance to prevent the handle from being moved back - it is consequently somewhat liable to fail in unskilful hands." The Company used Wheatstone's patented aerial cables of 1860. A "telegraphic rope" containing from thirty to a hundred earth-return copper wires of a fine No 22 gauge each insulated with india-rubber overlaid with cotton tape was suspended from a single strong iron wire (or, if necessary on short spans, an iron rod) sustained by wire-stayed, roof-top metal poles or "straining posts" each one mile apart with some intermediate supports. The iron-wire stays were buffered with india-rubber cylinders to reduce wind noise and damaging movement. Each insulated copper wire was individually numbered and represented one client circuit, at every straining post was a complex connection box from which a circuit might be taken off to serve a client. The circuits in the cables were coloured red for one direction and black for the other. These aerial cables were laid along side streets rather than busy thoroughfares to avoid public annoyance. The copper wires were protected by the patent caoutchouc insulation made by S W Silver & Co.Although the Company had problems with Silver's patent india-rubber insulation the aerial cables proved more robust and weather-resistant than conventional roof-top iron-wire circuits, as well as being cheaper than subterranean lines. It planned to suspend its aerial cables in interconnecting triangular sections across London, each leg of one mile length. The properties at the points of triangulation were to be acquired by the Company and rented out after it had installed its masts and boxes on the roof. Outside of London the wooden test boxes, containing the junctions from the many private circuits, were attached to the poles or to the sides of houses, rather than at roof level. In London in 1863 it maintained its major route from Finsbury Square in the City, for Reuter's night office, south down Wilson Street, across Finsbury Circus, Draper's Gardens and Angel Court to the Stock Exchange, by Reuter's day office, down Birchin Lane and Clements Lane to Cannon Street. It then carried due west along Cannon Street, Ludgate Hill, Fleet Street, the Strand to Charing Cross, then south down Whitehall to the Houses of Parliament. It had a branch from Ludgate Hill to the Central Criminal Court, another from Charing Cross to Waterloo Place, for Reuter's West End office, and to St James's Street at Pall Mall. Wheatstone was a director of the Universal Private Telegraph Company throughout its existence and was extremely active in its promotion. i.] The United Kingdom Electric Telegraph Company Their American telegraphs and associated relays were
supplied by Siemens, Halske & Company of London. It used the same
‘European Alphabet’ that was worked by the Electric Telegraph Company
and all of the continental systems. One cost-saving novelty adopted by the United Kingdom company was the attachment of cast-iron brackets for its insulators to some of the many tall factory chimneys of the north of England, and suspending its wires between them at great height and over a great span. In at least one instance the bracket fell off and damaged the factory roof beneath. The method of ascending the great factory chimneys to attach the brackets was that devised in 1845 by James Duncan Wright, a Scotsman living during the 1850s and 60s in Ramsbottom, Lancashire. A large square kite, in two pieces, of a size needing two men to work its two ropes, was flown over the chimney allowing a long cord to run across its mouth. Once in position the cord drew across a rope which connected with a length of chain. Once the chain was secure around the head of the chimney, a single block pulley and rope was raised to the top and used to haul up a wooden seat or platform from the ground from which to work. The kite and pulley was a far simpler and cheaper means of access than applying scaffolding to the whole shaft. The kite apparatus was widely imitated in the north of England, being used for making repairs and, especially, for installing copper-rope lightning conductors, as well as for telegraph brackets and insulators, to factory chimneys up to 450 feet in height.
The Hughes Type-printing Telegraph 1863 The Hughes type-printer, which produced messages printed in roman alphabet on a paper tape at a high speed, was only gradually introduced on circuits with the heaviest traffic, even some of the Company's long-lines relied on the American telegraph until business justified the change. Hughes' first success had been on the long line between Paris and Bordeaux in France, a distance of 575 kilometres, using the original version of his printer. The circuit was completed there in September 1860; Prof Hughes was on hand, as he was later in England, to instruct the French clerks in its operation. A version improved by Gustave Froment, his manufacturer in Paris, was introduced in the following year and that was adopted by the United Kingdom company. The Hughes instrument proved important, it is therefore proper to describe its action: it had a keyboard similar to that on a piano, the separate keys being connected to vertical rods arranged in a circle. Pressing a key raised the tip of the associated rod above the normal level. Concentric with this circle of rods was a rotating vertical spindle that carried an arm called the 'chariot'. This swept around over the tips of the rods and was engaged by any one protruding. The engagement was thus transferred mechanically to an arm with contacts in the transmitting circuit so sending out a momentary signal current. The spindle rotating the 'chariot' was geared to a printing-wheel having raised characters on its outer periphery so that as the 'chariot' rotated one revolution so did the printing-wheel, which presented in turn the individual printing characters to a strip of paper. It was raised into contact by a further simple mechanism and released by the signal current. The sending and receiving instruments had to be synchronised but this was achieved by a simple technique of interchanging recognised signals. David Hughes' patent
was bought in shares and he became a director of the Company when it
acquired his UK patent in 1862, remaining on the board until the firm
was appropriated. The Company purchased all of its Hughes
printers from his associate in France, the instrument maker, Gustave
Froment, of rue Notre Dame des Champs 85, Paris. Latterly the perfected Hughes apparatus was the most widely-used instrument for long overland and short submarine circuits in Europe, Asia and Latin America, enduring for nearly a century, until the 1950's in rural use, when it had long been superseded by the more effective and complex teletype and telex. It well outlived Cooke & Wheatstone's and even the American system in public telegraphy.
A sample message from Hughes's type-printing telegraph 1864 The
American telegraph, with the key-and-writer or inker, was retained for
many branch circuits throughout the United Kingdom company’s existence
and it was eventually used in its European connection working the
‘European Alphabet’ or dot-and-dash code. The ‘Electrician’ magazine of July 6, 1862 gave an elaborate description of Gaetano Bonelli’s new typo-telegraph, as displayed at the International Exhibition in London during that summer. “We will endeavour briefly to describe the modus operandi of Signor Bonelli’s system. “Let the reader suppose himself to be the opera-tor; before him he will find an oak table, 6½ feet in length 17 to 18 inches wide, along the centre of this table runs a miniature railway, terminated at either end by a spring buffer, and spanned mid-way by a kind of bridge 6 inches in height and 2 ½ or 3 inches wide. Upon this railway is placed a species of wagon, 1 yard long and 5 inches wide, 3½ in height, running upon four brass wheels: on the surface of this wagon are two long rectilinear openings - the one occupying the upper half and destined to carry the message which is to be sent, the other occupying the lower half, and intended for the message which may be to be received, upon the bridge are two small metal combs, each containing a number of insulated teeth, answering in number to, and connected with, the insulated conductors of which the line is formed. The combs differ from one another, the one which is to despatch the message being formed of so many teeth having a certain freedom of action is on the side of the bridge farthest from the operator; the other, or writing comb, is formed of a similar number of teeth fixed in a block of ivory, and forms a perfect line, which rests with a slight but regular pressure transversely on the paper, and occupies the nearer portion of the said bridge. Bonelli's Typo-Telegraph 1863
A chemical type-printing telegraph used between Liverpool and Manchester “We will suppose that the tables have been tested, and that a number of messages have been sent for dispatch; these messages are distributed to a given number of compositors, who set them up in ordinary type with great rapidity; the first that is finished is handed to the operator, whose wagon has already been pushed to the upper end of the rail and is held there by a simple catch, he places his dispatch in the opening destined for it, and in the second opening he places a plate of metal upon which has been laid four, five, or six strips of paper prepared with a solution of nitrate of manganese ; this done, he turns a small handle and watches if the operator at the other end has done his work; the wagon is at once freed from the catch, and is set in motion by a simple weight, the pace being regulated by a fan. The type of which we have spoken is thus brought under the action of the despatching comb, and runs lightly under its teeth from end to end; one half of the journey being made, the writing comb comes in contact with the prepared paper. If the operator at the other end has had a message to send it will have been printed in clear, legible characters, of a deep brown colour, answering with unerring fidelity to the forms over which the corresponding type comb has passed while the operator (the reader) learns that his message has as surely been received; the message is stripped off, the wagon remounted, the type-box changed, and the process of transmission and reception repeated. All this, which takes so long to describe, is so rapidly accomplished that from 450 to 500 messages may be dispatched per hour, the passage of the wagon occupying 10 to 12 seconds, during which time a message has been sent and received at each end of the line. “It will be seen at once that it is morally impossible that any demand should arise that would over-tax the transmitting powers of this system, the whole question resolving itself into rapidity of supply. Now, ordinary compositors can set up a message of 30 words in one and a half minutes, this period is, of course, divisible by the number of compositors, ten giving ten messages each minute and a half, twenty giving twenty messages, and so on. By this happy application of electric science to the typographic art, it is believed that the price of dispatches will be reduced to a minimum, and the rapidity of distribution vastly increased, while the chances of mistake are almost annihilated, being reduced to the possibility of typographic error, in the first and only process in which error appears to be possible. “It is scarcely needful to say that the dispatch received is actually sent out; as the wagon descends it is stripped from the plate, passed for a few seconds under a stream of water, blotted off, dried by hot rollers, and put into the envelope, which is, by this time, ready to receive it.” k.] The Indo-European Telegraph Company The Company's line consisted of two 6mm gauge iron wires, much stronger than the common 4mm or 5mm gauge used in Europe. An extra domestic wire was added in places. They were suspended from Siemens patent iron-capped earthenware insulators on 70,000 posts with wood shafts in Poland and Russia and Siemens patent cast-iron shafts in the Caucasus and Persia. The patent poles were manufactured by Siemens Brothers in Greenwich, London. These had a seven foot tall, four inch diameter, hollow cast-iron column with a twenty-one inch square base piece buried in the earth for stability. Into this was inserted a slightly conical twelve foot tall iron extension, with a twenty inch long lightning rod at its extremity. A small iron bracket near the tip carried the two insulators, one on either side. The patent insulators consisted of a cast-iron cup with a side flange to attach to the pole bracket. The iron cup had an inner earthenware insulator cemented within from which an iron hook protruded, to which the line wire was attached. Siemens Brothers also made the armour for the short-lived Black Sea cable; Hooper's Telegraph Works Company provided the india-rubber insulation. l.] Technical Miscellany These were replaced, after extensive comparative tests of English, American, French and German instruments, during 1854 by the American telegraph. Exploders The Gutta Percha Company had made hundreds of miles of "sulphuretted gutta percha" insulated wire for Siemens & Halske in Prussia in 1849. Unfortunately, at least for the purposes of telegraphy, it was found that a copper wire covered with sulphuretted gutta percha allowed sulphide of copper to form on the interior of the resin. If the copper wire breaks or is cut the current passes through the sulphide, this becomes incandescent and then ignites the resin. This accidental discovery was utilised by Samuel Statham of the Gutta Percha Company and marketed as Statham's Fuze. A short length of wire in a thick coat of gutta percha with a high sulphur content was left for several months until the sulphide had formed. A small portion of the resin was then cut away to expose the wire and a gap of a quarter inch made in the copper. It was found by Michael Faraday in 1854 that gunpowder fired "with certainty" using this fuze at the end of eight miles of wire, and he tested it successfully over 100 miles! He also ignited six fuzes in succession. Statham's Fuze, being so cheap and simple, was used for many years in demolition works, detonating gunpowder and gun cotton. Its disadvantage was that it required very powerful galvanic batteries or smaller batteries and induction coils to work reliably. To make it more sensitive Statham's Fuze was later charged with fulminate of mercury, six mines were thus simultaneously detonated at dock works in Cherbourg in France at a distance of 300 yards using a small induction coil and a single cell during 1860. The British Army used a galvanic fuze in proof-firing artillery. This had a quill or tube with a wooden head, filled with fine gunpowder, containing two copper pins connected within by a superfine copper wire. Passing a current from a galvanic battery through the pins caused the wire to heat and ignite the surrounding powder. It was not widely used. There was great inconvenience in using batteries of liquid-filled cells and induction coils in the field, particularly in military demolitions. Unsuccessful experiments were tried with W T Henley's lever-operated magneto-electric machines, similar to his telegraphs, and Statham's Fuze in the 1850s. Charles Wheatstone and Frederick Abel, the government chemist, undertook a series of trials from 1855 which resulted in Wheatstone's Magnetic Exploder that was patented in 1860 and Abel's Magnet Fuze. The Magnetic Exploder, the first electric blasting machine, contained six small magnets rotating on a common axis and six fixed sets of coils that generated a sure powerful current. It ignited from two to twenty-five Magnet Fuzes instantaneously through a single gutta percha insulated copper wire. The Magnetic Exploder was widely used in colonial mining and by the British Army from 1861. The Confederate States acquired several to detonate submarine charges, known then as torpedoes, under abolitionists' ships in 1864. The Magnet Fuze was the detonator used with the Magnetic Exploder, inserted in charges of black powder or the much more powerful new explosive, gun cotton. It had a box-wood head with a long copper primer filled with phosphide of copper and a tubular case of black powder. Frederick Abel went on to invent the high explosive, cordite. Projectile Velocity It was tried in tests of James Mackay's experimental "windage" gun on Crosby Sands, near Liverpool, late in March 1864. The piece was 8 inches in calibre and weighed 9 tons, forged by the Mersey Steel & Iron Company, firing a 170 pound steel bolt. It was fired at a target armoured with 5½ inches of iron backed with 9 inches of teak, and pierced it at 200 yards range. The velocity of the gun was measured electrically by Newman's apparatus as 1,640 feet per second. Rutter's Electric-Indicator 1847 The principles of electric telegraphy were introduced to the defence of property in the 1840s; and its very first application in Britain was contrived to cover virtually all such domestic dangers. John Rutter, engineer to the Brighton Gas Company and a popular writer on gas and electricity, patented the first electro-magnetic fire and burglar alarm "system" in June 1847, the Electric-Indicator. This consisted of mercury thermometers with two platinum wires sealed in the tube in each room; mercury-filled switches attached to each door and window; a galvanometer; and a clockwork alarm bell with an electro-magnetic release, all connected by a copper wire circuit. In the case of fire once the temperature drove the mercury up to the platinum wires a circuit was completed and the alarm released; in case of "trespass" closing or opening a door or window brought a wire in contact with the mercury switch and set off the bell. The circuit worked in one direction for fire and the other for burglary so that the left or right movement of the needle of the galvanometer, located in "the master's sleeping room", signalled which danger was imminent. Rutter's patent Electric-Indicator was demonstrated and marketed by Francis Whishaw at his Adelphi showrooms in 1848 and by Horne, Thornthwaite & Wood, instrument makers, 123 Newgate Street, City, in 1850. By 1851 it was being manufactured at the works of the telegraph engineer, W T Henley in Clerkenwell, in which year an improved version was introduced. In 1850 Rutter's Electric-Indicator consisted of two neat mahogany boxes, one containing a battery of six Smee zinc-silver cells that would last "many months" with a small galvanometer inset, the other containing the clockwork alarm, the trigger-weight and the electro-magnetic release for the trigger. There were two circuits, one with red-covered wire, the other with green-covered wire, and a white-covered return for both. The red circuit against thieves was attached to so-called 'circuit plates' on drawers, closets, boxes, windows and doors, the green circuit to electric thermometers in rooms and passages. The green circuit for protection against fire was always connected to the alarm; the red circuit was turned in and out of use by a single ivory knob on the alarm. A key was used to span the clockwork alarm. The original mercury trip switches were now replaced in the concealed 'circuit plates' by springs that closed the electric circuits once a door, window, lid or drawer was opened. As in the original specification the small galvanometer had the green circuit wound one way and the red another to give an indication of either fire or burglary when the alarm was released. To prevent unnecessary battery loss the circuit was automatically broken once the alarm bell was sounded. Shelves of early Cruikshank batteries in the basement of the Batteries
These first cells, each of a pair of metallic plates, were arranged in teak or oak troughs – forming the battery of cells. In 1847 these batteries were 24 inches long by 6 inches wide; latterly, from 1850, the troughs were 30 inches by 5½ inches with twenty-four slate-partitioned cells. These, and their successors, were primary or, what are now called, fuel cells creating electricity, and not storage cells that could be recharged. Battery power was measured on the galvanometer or detector in degrees of deflection of the needle, from 0° to 90°. In the line circuit this varied for many reasons; the number and condition of the cells, the state of the insulation and the ambient state of the weather, in particular atmospheric moisture. A Daniell Cell 1855 The most significant cell in telegraphic service was that devised by John Frederick Daniell, a colleague of Charles Wheatstone at King's College, London. This was a copper-zinc device with two liquid elements contained in a glass jar, invented in 1836 and introduced into the industry in 1852. This had the considerable advantage of being constant in its output. It was known generically as the "sulphate battery". The Daniell cell was improved in 1853 by John Fuller, reducing its cost by one-third. In modern measurement each sulphate cell produced a constant 1 volt. There were many minor improvements to the
sulphate cell made by the companies' electricians and others over the
years; the improvers each lending their name to these differences. A Battery of Daniell cells, used from 1855 Sir William Robert Grove devised the zinc-platinum or nitric acid cell in 1839; this had twice the constant output (c. 2 volts) of a similar Daniell cell. Bunsen replaced the expensive platinum element with carbon in 1840. The powerful nitric acid battery was commonly used in telegraphy the United States from the outset of their lines. As it gave off toxic nitric acid fumes it had to be replaced by the sulphate cell in America during the 1860s. The main stations of the companies possessed several hundred Daniell or other sulphate batteries to drive their many circuits; these were never used in total as they needed constant maintenance and repair by the battery-men. The Electric company alone had 96,000 sulphate cells in use by 1854. In 1857 John Muirhead of the Electric Telegraph Company redesigned the Daniell cell so that its batteries were formed of "chambers" in their cases rather than of fragile glass jars, making them more robust and portable. The Muirhead sulphate battery was the commonest in service during the 1860s. A Muirhead Battery 1857 The Intercontinental Cables
It was noted that the already damaged first American cable of 1858 with
its thin copper conductors was finally burnt out when the equivalent of
2,000 volts, from 312 Daniell cells with multiplying induction coils,
was passed through it by S F B Morse's protégé, E O W Whitehouse.
As an experiment the engineer Latimer Clark had the 1865 and 1866
cables connected in Newfoundland and sent signals back-and-forth across
the Atlantic from Valentia on their combined length of 3,500 miles
using Thomson's mirror galvanometer and a single cell "pygmy battery"
made from a silver thimble. The Atlantic cable of 1866 could be driven
by just twelve Daniell cells (c. 12 volts), but twenty or thirty were
commonly used.
Thomson's Mirror Galvanometer 1858 Technical Costs From E B Bright's evidence of 1853 it is known that W T Henley's magneto-electric two-needle telegraphs cost £15 each. In the Indian context, locally-made 'reversers' for sending cost 24s 0d each, 'telegraphs' or galvanometers for receiving 4s 0d and turnplates for switching 2s 0d. The finest brown stoneware insulators by Bourne of Denby were available at 5d each in London; and Mitchell's patent iron screw-piles for poles, made by Ransom & Sims of Ipswich, at 6s each. Joseph Whitworth, the engineer appointed by the government to report on the American telegraphs in 1852, observed that the simple Morse register cost £8 ($40) and House's complex type-printer, £50 ($250) there. In technical context, marine chronometers, highly accurate clock mechanisms in brass and steel, cost between £21 and £25 in London during 1855. Ten years or so later, sample buying-in costs for
contemporary telegraphic apparatus and common supplies for telegraphy
in the 1860s were: Hughes Type-Printing Instruments………£60 In the late 1860s Theiler & Sons of Islington were selling their patent portable single needle telegraphs for £4 10s, their patent American telegraphs with inkers for £12 0s, older pattern American telegraphs with embossers for £10 0s, American keys and relays for £6 0s, alarums for £2 0s and upright galvanometers for £2 0s. Siemens magneto-electric dial telegraphs cost £19 each in the mid-1860s, whereas the best price for one of Wheatstone's competitive Universal instruments was £25. Henley's magneto dial was said to cost £16. These were far more complex in manufacture than the galvanic needle and American apparatus. Sample Material Costs 1864 Timber Insulators Wire From 'The Telegraphic Journal', January 16, 1864 Instrument Performance In the earliest days of the telegraph, between 1845 and 1848 the transmission rates with the two-needle telegraph were remarkably slow. A rate of six words a minute was the norm on the Electric Telegraph Company in that period. The Queen's Speech in 1846 was sent at seven words a minute from London to Southampton. It was this poor performance that required the introduction of translation into abbreviations for transmission. As performance improved, due to clerks' practice and better insulation of the lines, there was a move back to sending simple text. However by 1850 sample sending speeds on the Electric company's two-needle instruments were recorded at between 23 and 26 words per minute; achieving 45 words in October 1849 and 52 words in July 1850 when transmitting mainly figures. William Thomson pointed out in 1860 that much of the improved performance was achieved by "slimming down" the needle apparatus. The reduction in weight and travel of the heavy drop handle, its subsequent replacement by the hand pedal or key, and the reduction in size and weight of the needles, all contributed to the increase in speed of transmission in the 1850s. C V Walker in 1850 estimated the average speed of a two-needle telegraph on the South Eastern Railway circuits as 16¼ words per minute. J S Fourdrinier, the Electric's secretary, said that in 1854 the same device was customarily sending at 21¼ words per minute, whilst E B Bright of the Magnetic stated that their two-needle Henley telegraphs were working at 27 1/3 words per minute. The manually-worked Bain printer apparently achieved only an average of 19½ words a minute at that time; although it had been recorded as sending at 38 words a minute in October 1849. In comparison Henry O'Rielly in New York said that his American recorders worked at 20 to 23 words a minute. Bright's Bell telegraph, an acoustic instrument, with Highton's twin tappers was, according to his brother, capable of working at from 30 to 40 words a minute. This was generally agreed to have the fastest transmission rate of any apparatus in common operation by ordinary clerk-operators in Britain. Latterly, taking several contemporary sources regarding instrument performance it is recorded that the double-needle telegraph could be worked at 45 words per minute; the single-needle could achieve 35 words per minute in skilled hands, but averaged 27 words per minute. The American key-and-writer averaged about the same message rate as the single-needle device. The universal telegraph could work at a maximum 20 words per minute (but more usually at 5 words per minute); whilst both the very sophisticated House and Hughes printers could send and print alphabet at up to 54 words per minute. The Wheatstone automatic telegraph in common service from London achieved 120 words per minute to Manchester, 90 to Sunderland in the north-east of England, 60 to Aberdeen in the north of Scotland and 40 to Dublin by underwater cable. The simple American 'sounder', an acoustic receiver, almost universal in the United States from the mid-1850s and familiar to current audiences for cowboy films, was introduced only at the end of this period by the Electric company but not at all used in Continental Europe where the American (actually a Siemens or Digney) inker or writer predominated. The bureaucratic need for another level of permanent record prevailed over economy. The circuits of the Atlantic and the other intercontinental cables were worked by current reversing keys and Thomson’s mirror galvanometer. During 1867 the average speed of sending from Ireland to Newfoundland was eight words a minute.
The Battery Cellar at Telegraph Street Workshops The Magnetic company had similar shops in
Bolton, Lancashire, near its head- quarters in north-west England, for assembling
insulators, manufacturing and maintaining batteries and general storekeeping. In 1869 these two factories employed 175
people. There were many small workshops in London
and Birmingham, connected with the scientific instrument and clock-making
trades, which made components and assembled instruments for the telegraph industry.
None, except those of Reid, Wheatstone, Siemens and Henley, approached the Companies’
shops in size. Private Lines Two sets of Breguet dial instruments, with batteries, iron wire, insulators and everything except poles, ready for fixing for a one-mile private circuit cost £30 in 1868. l.] Technical Legacy The Electric Telegraph Company's great allies, the railway
companies, defiantly retained Cooke & Wheatstone's and Highton's
single-needle telegraphs in their own track-side circuits for another
century.
The Queen's Telegraph 1851 - 1880 |
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Telegraph, from the Greek “tele”, distant, and “graphos”, writing |
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© Copyright - Steven Roberts 2012 |