444 POPULAR LECTURES AND ADDRESSES. 



Deepest Water to be encountered, 2,400 fathoms, 

 being less than 2\ nautical miles. 



Length of Cable Shipped, 2,174 nautical miles. 



New Atlantic Cable, 1865. 



Conductor. Copper strand consisting of seven 

 wires (six laid round one), and weighing 300 Ibs. 

 per nautical mile, embedded for solidity in Chatter- 

 ton's compound. Diameter of single wire -048 = 

 ordinary No. 18 gauge. Gauge of strand '144 = 

 ordinary No. 10 gauge. 



Insulation. Gutta percha, four layers of which 

 are laid on alternately with four thin layers of 

 Chatterton's compound. The weight of the entire 

 insulation 400 Ibs. per nautical mile. Diameter of 

 core '464 of an inch; circumference of core 1*46 

 inches. 



External Protection. Ten solid wires of diameter 

 095 (No. 13 gauge) drawn from Webster and 

 Horsfall's homogeneous iron, each wire surrounded 

 separately with five strands of Manilla yarn, 

 saturated with a preservative compound, and the 

 whole laid spirally round the core, which latter is 

 padded with ordinary hemp, saturated with pre- 

 servative mixture. 



Circumference of Finished Cable, 3*534 inches. 



Weight in Air, 35 cwt. 3 qrs. per nautical mile. 

 Weight in Water, 14 cwt, per nautical mile. 



Breaking Strain, 7 tons 1 5 cwt, or equal to eleven 



