1851 Great Exhibition: Official Catalogue: Class X.: Electric Telegraph Co
ELECTRIC TELEGRAPH COMPANY, Office, South Entrance to the Exhibition Building — Proprietors.
Electric Telegraphs.
1. Original five-needle telegraph invented by Cooke and Wheatstone in 1837, and worked on the Great Western Railway.
2. First complete telegraph for intermediate stations requiring four wires and a return circuit. Cooke and Wheatstone's patent of 1838.
3. Two-needle portable telegraph. Intended to be carried by guards of trains and attached at any required part of the line to the telegraphic wires, thus opening an immediate communication between the spot of an accident and the stations on the line. Cooke and Wheatstone's patent of 1838.
4. Ordinary two-needle telegraph of the construction now in use throughout the whole of England. Constructed under Cooke and W heatstoue's patents of 1837, 1838 and 1845.
5. Two-needle telegraph of the most recent form; constructed under the same patents as the last, but with modifications and improvements of parts.
G. Ordinary single-needle telegraph, used for small and second-rate stations. Constructed under the patents of 1837, 1838, and 1845.
7. Portable galvanometer, or detector used for tracing out faults on the lines. Patent of 1837.
8. Portable single-needle telegraph to be carried by guards of trains. The dial arranged in a sloping position to facilitate the reading of the signals. Patent of 1845.
Electro-magnetic Alarums.
1. Electro-magnetic alarum: patented in 1847 by Cooke and Wheatstone. In this alarum the magnet operated directly to impel the hammer against the bell. A secondary battery was brought into action to excite the magnet.
2. Electro-magnetic alarum of 1837; the magnet only operating to release the striking machinery.
3. Electro-magnetic alarum of 1838. The striking machinery released by the deflection of a magnetic needle.
4. Small decomposition apparatus. This apparatus, or an ordinary magnetic needle, was used to bring into operation a secondary battery at the station where the signal was to be received.
5. Electro-magnetic alarum. The magnet excited by the direct current transmitted, and not by a secondary battery. Patents of 1837 and 1840.
6. Large alarum used for signalling at the entrances of tunnels at railway stations and other places where a loud sound may be required. Cooke and Wheatstone's patents of 1837 and 1845.
7. Another form of the same alarum.
8. Plan proposed by G. Little for sounding a bell by the self-action of an electro-magnet.
Disc Telegraphs.
1. Disc telegraph: the signals given by the step-by- step rotation, and pausing of a disc bearing letters or figures. The rotation produced by the action of an electro-maguet. Wheatstone and Cooke's patent of 1840.
2. Disc telegraph: the letters or figures pointed out by the rotation and pausing of an index or hand operating by electro-magnetic action. Patent of 1840.
3. Disc telegraph: similar to No. 1, except that signals are given by numbers.
4. Modification of the disc telegraph proposed by Nott.
5. Disc telegraph: the communicator, or signal-giving apparatus being conjoined to the instrument.
6. Modification of the disc telegraph arranged for a counter, or register of any successive movements or actions, such as persons passing through a door or gate, strokes made by a steam-engine, fly or other press, etc.
7. Magneto-electric communicator for the disc telegraphs: no battery is required, a permanent magnet furnishing a constant series of induced currents by the rotation of an armature and coils over its poles. Wheat- stone's patent of 1841.
8. Second form of the magneto-electric communicator, adapted to work disc telegraph, giving signals by numbers.
Double Index Disc Telegraphs.
1. Double index disc telegraph: the two hands move independently, so that one may be set to give any required permanent signal, while conversation is carried on by the other. This instrument was arranged for working the atmospheric machinery on the South Devon Railway. It requires one wire only. Hatcher's patent of 1847.
2. Double index disc telegraph. The two hands revolve step by step in opposite directions. They would therefore indicate exactly at all stations on a single line the progressive movement and approach of two trains running in opposite directions. Patent of 1847.
3. Single index disc telegraph. The index can be made to rotate in either direction, so that the speed of signalling would be increased by the facility with which any position could be given to the index by a few movements. Patent of 1847.
Printing Telegraphs.
1. Elective magnet printing telegraph. The signals are printed in ordinary type, according to the first arrangement of Wheatstone in 1841. The current when sent in one direction moves the type wheel to the required position, and when reversed brings into operation the printing machinery. Hatcher's patent of 1847.
2. Second form of the elective magnet printing telegraph. Patent of 1847.
3. Third form of the elective magnet printing telegraph: the signals being printed not in type but in combinations of dots or points.
4. Type printing telegraph: the type wheel, after each signal is printed, is released from the machinery and regains its zero or quiescent position at one bound, thereby increasing the correctness of the operation by making each signal wholly independent of the correctness or incorrectness of the preceding one. Barlow and Forster's patent of 1848.
5. Chemical printing telegraph: signals given by dots or spots arranged in two lines. The marks produced by the chemical action of the current on a prepared paper. Alexander Bain's patent of 1846.
6. Chemical printing telegraph: signals given by dots and lines combined in various ways. Bain's patent of 1846.
Magneto-electric Machines.
1. Magneto-electric machine. Currents induced by the permanent magnet can be sent in one direction by this machine. It is used for the sounding of alarums. No battery is required. Wheatstone's patent of 1841.
2. Magneto-electric machine for sending currents in either direction at pleasure. Used for working the double index telegraphs. Hatcher's patent of 1847.
3. Induced currnet machine: an inducing battery of small power is used with this form of machine. It sends currents in either direction like the last. It was used for working the double index telegraphs on the South Devon line. Patent of 1847.
4. Second form of induced current machine: arranged for working with the code of signals in use by the Admiralty. Patent of 1847.
Galvanometers.
1. Indicator or galvanometer in which the magnetic needle is replaced by a magnetised steel disc. Mapple's patent of 1847.
2. Simple current director for causing the current to ring either of two bells or to actuate either of two instruments.
3. Simple current director for ringing either of two bells as for an office.
4. Current director, for causing the current to sound either of three bells, or actuate either of three instruments.
5. Current director or switch for a line of telegraph with two wires to any one of three other lines of similar telegraph. Switches of this kind are extensively used in England.
6. Punch or stamp used for cutting out in paper the signals or combinations of dots and lines to be transmitted by Bain's chemical telegraph. Bain's patent of 1846.
7. Stick or rule of type used with Bain's printing telegraph.
A series of insulators of various forms constructed under Cooke and Wheatstone's, Ricardo and Clark's, and Mapple's patents.