234 SCIENTIFIC RECREATIONS. 



when the subject was discussed. We need not enter into the details of the 

 controversy. Mr. Morse won the day, and patented his invention. 



"It was once a popular fallacy in England and elsewhere that Messrs, 

 Cooke and Wheatstone were the original inventors of the electric telegraph. 

 The electric telegraph had, properly speaking, no inventor. . . . Messrs, 

 Cooke and Wheatstone were, however, the first who established a telegraph 

 for practical purposes comparatively on a large scale, and in which the public 

 were more nearly concerned. . . . Therefore it was that the names of these 

 enterprising and talented inventors came to the public ear, while those of 

 Ampere and Steinheil remained comparatively unknown.* The telegraph, as 

 used in Great Britain, was the result of the co-operation of Professors Cooke 

 and Wheatstone. 



Mr. Cooke, in 1836, having seen the need> telegraph when in 

 Heidleberg, made certain designs, and soon entered into partnership with 

 Professor Wheatstone for the application of electric telegraphs to railways. 

 Their apparatus with five needles and five wires was put up on the 

 London and North-Western (then London and Birmingham) and Great 

 Western lines, but proved too expensive. The instrument was 

 subsequently modified, and is used on the English railways still. 

 We may now proceed to look at the Wheatstone needle 

 telegraph and see the method of working it. We know already 

 that when a pair of metallic plates are immersed in a fluid 

 which acts chemically more rapidly on the one than the other, 

 and a wire connects the upper parts of these plates, this won- 

 derful agency is set in motion, and circulates from the one 

 'ig. 342. oil. plate to the other (fig. 242). This arrangement may be best 

 shown by using one plate of zinc and the other of copper, and a dilute solution 

 of sulphuric acid for the liquid ; this, however, produces by far too little of the 

 agent to be used on a telegraphic line, there are therefore combinations of such 

 pairs of plates, so arranged that the power of one pair shall be added to the 

 next in such a way that at the end of the series (called a " battery") there 

 shall be a great increase of the power accumulated ; this arrangement is 

 shown in fig. 244. Now (if the power be sufficient) it does not signify what 

 length of wire there may be between the two ends of this arrangement or 

 "battery"; whether they be connected by a few feet or many hundred miles,, 

 the electricity passes instantaneously from one end to the other ; and 

 furthermore, it has been found in practice, that this electrical influence can 

 be transmitted through the earth in one direction if sent by a wire in the 

 other ; for instance, 'if a wire from one end of the battery be carried on from 

 London to Liverpool, instead of having another from Liverpool to London, 

 to connect the two ends of the battery, it is found to answer the same 

 purpose if the end of the wire at Liverpool be fastened to a plate of metal 

 buried beneath the surface of the earth, and the other end of the battery at 

 London furnished with a similar plate, also buried. In this arrangement,. 

 * Sabine : " The Electric Telegraph." 



