.V/A- \vi i.i.i AM .sy/-;.i/A\v.v, r.R.s. 35 



sending messages at an efficient rate for commercial purposes 

 remains yet to be solved, for theory and experience combine 

 to prove that the highest rate likely to be attained in working 

 through a distance equal to the intended Atlantic cable, in taking 

 full advantage of the power of waves, will not exceed three, or it 

 may be four, words per minute, unless indeed some new prin- 

 ciple of working is yet discovered, whereby a greater result is 

 realised. 



There would be one way, indeed, in which the capabilities, not 

 only of long submarine cables, but of electric telegraphs generally, 

 might be greatly increased, which consists in combining a number 

 of insulated line wires into one cable, and working them in metal- 

 lic couples. This, indeed, is giving up the earth circuit, but, in 

 its stead, we gain the power of several sets of instruments without 

 disturbing interference between the wires by Voltaic induction. 

 Instead of using one of the wires (say the central wire) for the 

 common return circuit, the metallic circuits might be selected 

 by the rule of permutations, which, if carried out, would enable 

 us to connect 6 pairs of instruments by means of 4 wires, 10 

 pairs by means of 5 wires, and so on. If a cable of 10 wires 

 was laid between two great commercial centres, say between 

 London and Liverpool, as many as 42 pairs of instruments might 

 be used, which might be placed in the counting-houses of great 

 merchants and of their respective agents for their private corre- 

 spondence, and this step would probably give rise to the more 

 general application of the electric telegraph for private and 

 domestic communication. The instrument that appears to be 

 best suited for such purposes (including railway and town services) 

 is a magneto-electric step-by-step or dial instrument, a specimen 

 of which I have placed before the meeting. This instrument 

 combines the advantages of requiring no battery, with great facility 

 of working, and it contains some novel arrangements, whereby 

 its action is rendered powerful and certain. 



Of these instruments, 180 were adopted last year by the 

 Bavarian Government, in lieu of instruments of a similar class 

 that had been used there previously, and it appears, from an 

 official document, that they give great satisfaction. A pair of 

 them is also in use at the War Office and the Horse Guards ; and 

 another pair \vas taken out by Messrs. Newall & Co., to keep up 



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