418 SIR RODERICK I. MURCHISON'S ADDRESS. [May 25, 1857. 



Useful Inventions. 



The Atlantic Telegraph. — At the liead of the list of useful inventions 

 in the course of application, must unquestionably be placed the 

 Great Atlantic Electric Telegraph. 



The series of nautical observations recommended for statistical 

 purposes, in reference to the meteorology and physical geography 

 of the sea, by the Maritime Congress held in Brussels in 1853, 

 followed by the co-operation therein of the mercantile and govern- 

 mental navies of the countries there represented ; the subsequent 

 writings and investigations of Lieut. Maury, u.s.N., founded largely 

 upon those observations, and the soundings of Lieut. Berryman and 

 others in the Atlantic Ocean, have determined the path which 

 seems at present to be the only practicable one for successfully 

 submerging a telegraphic cable beneath that sea, and so uniting 

 Britain and America. 



This path would appear to lie, in a straight line, nearly due east 

 and west, between 48° and 55° N. latitude from the coast of Ire- 

 land to that of Newfoundland, along the course of which the depth 

 of water is believed to be nowhere greater than 12,000 feet. 

 The depth descends in gradual inclinations to that maximum, free 

 from sudden chasms or subaqueous promontories ; and upon a plateau 

 at the bottom of the sea there is formed an agglomeration by the 

 constant current of the Gulf stream, which proves, under micro- 

 scopic observation, to be composed of the minute shells of Fora- 

 miniferaj and Diatomaceae, and which, it is believed, will, in time, 

 form a complete incrustation over the outer metal of the telegraphic 

 cable. 



It is singular that in no other part of the Atlantic than across 

 this broad belt do conditions exist which, according to our present 

 knowledge, would justify an attempt involving so much scientific 

 interest, and so large a cost, as that of such a submergence of 

 telegraphic wires. 



To the southward of the Great Bank of Newfoundland, the bottom 

 of the ocean suddenly recedes into vast and uncertain depths, due 

 to some great former depression of the earth's crust, in many places 

 unfathomed, which leave a channel for the Gulf-stream, along the 

 whole of its course to the northward of the Gulf of Mexico. These 

 depths continue, with intervals of abrupt and almost precipitous 



