118 ANNUAL OF SCIENTIFIC DISCOVERY. 



mistake, and therefore the high tension induction coils, which were made by 

 Mr. Whitehouse, were not only unnecessary, but absolutely hurtful and dan- 

 gerous unless the whole length of the line was perfectly insulated in every 

 inch of its vast length, which, of course, it is impossible to expect that any- 

 thing made by human hands could be. The retarding influences of induction 

 which where so much spoken of while the cable was lying at Keyham, were 

 probably due to the inductive influence of one layer of the cable lying over 

 another in the coil ; for so little has it been experienced since the cable has 

 been laid, that Professor Thomson thinks if the line was in fair condition it 

 could be worked through with ease with a few battery cells of Daniel's con- 

 stant battery. 



That the wire is exposed to a considerable extent, in at least two places, is 

 well ascertained, and where a metallic surface through w r hich currents of 

 electricity are passing, is exposed to water, oxidation takes place by the 

 electrolytic decomposition of the water, and thus the wire must soon be 

 eaten away. This may be in a great measure avoided by transmitting all 

 signals with negative currents, which would .prevent the direct oxidation of 

 the wire by electrolysis ; but at the same time, according to the experiments 

 which have been made, both by Professor Thomson and Mr. Henley, an 

 exposed wire is not entirely free from a species of decomposition, even 

 when negative currents alone are transmitted through it. It soon became 

 encrusted with a light-colored substance, the precise nature of which is not 

 quite ascertained as yet, but it is supposed to be a combination of chloride of 

 copper with some of the organic compounds contained in the gutta-percha. 

 So, no matter what may be the result of the preconcerted experiments at 

 both termini of the wire, one thing cannot be doubted, viz., that, before per- 

 manent, certain, and rapid telegraphic communication can be secured 

 between Europe and America, another cable must be laid. 



Thus, for the present, the cable must be considered a failure, at least as 

 regards its paying and working properties. Nevertheless, in spite of all obsta- 

 cles, the attempt has demonstrated the ease, and, indeed, almost certainty, 

 with which, under ordinarily favorable circumstances, a submarine cable 

 across the Atlantic can always be laid; and ah 1 the theories of the cross cur- 

 rents which were to break the cable, the floats which were necessary to buoy 

 it up, and, above all, the idea that it could never sink to the bottom, are set 

 at rest forever. The cable has been laid, and has been worked through ; and 

 really, when we look for one moment at what that coil has had to undergo, 

 from the day the first mile of it Avas made up to the present time, it seems 

 nothing less than marvellous how it has been submerged, and still more 

 astounding that any signals ever came through it. On the very place where 

 the splice was made, in the centre of the Atlantic, an air-bubble, almost the 

 size of a coffee-bean, had to be cut out. How many hundreds of similar 

 places might there have been that were never seen ! The defective centring 

 of the copper conductor in its gutta-percha covering was also, no doubt, a 

 source of many serious faults ; for the reason that the gutta-percha, being 

 very thin in some parts, allows the powerful electric currents from the induc- 

 tion coils to pierce it and touch the outside wires. Once this fault, which 

 is technically termed " blowing a hole " in a cable, takes place, such a loss 

 of the signaling current ensues that the cable is rendered useless, or a great 

 augmentation of battery power is rendered necessary ; and when this last 

 remedy is resorted to, the hole becomes larger and larger, until the water, 

 getting freely to the wire, oxidates it away in a very short time. Such acci- 



