164 ANNUAL OF SCIENTIFIC DISCO VEltY. 



the charged poles of an electrical machine in such a manner that, during the 

 moment of each pin's passing, it forms electrical communication between 

 the instrument and the telegraph, and a signal is transmitted to the other 

 end of the wire, where the spark perforates a paper and records the message. 

 In consequence of a terrible gale during the latter part of the year 1856, 

 the two sub-marine cables between the French coast at Calais and Ostende 

 and the English coast at Dover were broken by a vessel dragging its anchor 

 over them. For some time after this, England had no communication with 

 the continent except by the way of Holland. The Calais connection has 

 now been reestablished. The engineer charged with this work made use of 

 the opportunity to examine the cable at the place of rupture, and he states 

 that the conducting wires were perfectly uninjured in their envelop of gutta 

 percha, notwithstanding the five years' immersion in sea water. 



THE SUBMARINE ATLANTIC TELEGRAPH. 



The first attempt to carry out the project of extending a submarine tele- 

 graph cable across the Atlantic, between the western coast of Ireland and 

 St. John's, Newfoundland, was unsuccessfully made in the month of August, 

 of the past year. Without entering into a detailed account of all the par- 

 ticulars of this important undertaking, it is sufficient, as a matter of record 

 in these pages to say, that after the successful deposition of 335 miles of 

 cable, the line broke, and the enterprise was for the present arrested. The 

 maximum depth attained to was upwards of 2000 fathoms, and the electrical 

 working of the cable up to the time of the accident, was in every respect 

 satisfactory. The general result of the undertaking has conclusively de- 

 monstrated that there are no insuperable obstacles to be encountered, and 

 that under more favorable circumstances the project will be successfully car- 

 ried out. 



The Directors of the Company, in a Report issued subsequent to an in- 

 vestigation of the accident, say : " Sufficient information has already been 

 obtained to show clearly that the present check to the progress of the work, 

 however mortifying, has been purely the result of an accident, and is in no 

 way due to any obstacle in the form of the cable, nor of any natural difficul- 

 ty, nor of any experience that will in the future affect in the slightest degree 

 the entire success of the enterprise. The only sudden declivity of any 

 serious magnitude (from 410 fathoms to 1,700 fathoms) had been safely 

 overcome, the beautiful flexibility of the cable having rendered it capable of 

 adapting itself, without strain, to circumstances which would probably have 

 been its ruin had it been more rigidly constructed. The combined influence 

 of the temperature of the water, and the compression of the pores of the in- 

 sulating medium, had practically shown that the action of a telegraphic 

 cable, so far from being impaired, is materially improved by being sunk in 

 deep water. These and all other circumstances which have been brought 

 out by the recent expedition have made more and more cheering and certain 

 the prospects of complete success on the next occasion." 



Since the commencement of the undertaking the electricians of the com- 



