THE ATLANTIC OCEAN. 219 



attempt will be renewed by any other line, or in any other 

 form.* But we may well venture to affirm that delay is a 

 lesser evil in this case than hasty and premature execution. 

 Besides those risks to the coating of the wires and to their 

 perfect insulation, which may depend on the depth and 

 other less known conditions of the Ocean bed, we are obliged 

 to admit that there are still difficulties in the theory of 

 electric currents, and of electric actions by induction, which 

 very especially apply to the case of long submarine lines for 

 telegraphic use. Some of the several conditions which were 

 suggested as likely to retard or otherwise impair a current 

 thus prolonged, have been made the subject of careful ex- 

 periment by those most competent to the research.f This 

 enquiry is still in progress, including especially all that relates 

 to the thorough insulation of the wires. So subtle is the 

 agent they are called upon to transmit, and so liable to 

 escape from its artificial channel, that a breach hardly per- 

 ceptible to the eye might be fatal to the integrity of a line, 

 otherwise perfect, across the Atlantic. We cannot better 

 denote the beauty and ingenuity of the experiments applied 

 to this object, than by stating that the electric current itself 

 has been made to indicate, within certain limits, the point 

 in the submarine wire where any fault or injury to insula- 

 tion has occurred, even though this be hundreds of miles 

 from the land terminus of the line. Scarcely indeed is 



* Another telegraphic route to America has since been suggested (we are 

 now writing in 1862) by the Faroe Isles, Iceland, Greenland, and Labrador ; 

 and partial surveys were made in 1860 to determine its feasibility. Such route 

 would avoid any sea line, equalling in length that from Valentia te Newfound- 

 laud ; but would incur various difficulties of execution/ and of maintenance in 

 working state, greatly diminishing, if not annulling, the advantage thus gained. 



f In connection with the experimental researches directed to the improve- 

 ment of the submarine telegraphic cable, as well as to the best methods of ' rapid 

 signalling,' by this great instrument, we must especially mention the name of 

 Professor Thomson, of Glasgow, than whom no one is better fitted by his 

 various acquirements, to solve the difficulties of the problem. 



