Proceedings of Learned Societies. 223 



the fishing of the river were actually putting up grates to prevent the 

 fish from going up the sewage drains. It was stated that in Cologne 

 and Belgium the dried deposit of the sewage was reduced to powder, 

 and in this form was sent all over France, where it proved a most 

 valuable manure. 



Mr. Fairbairn read a paper on the Mechanical Properties op 

 the Atlantic Cable. Several experiments were tried, and, re- 

 garding the ultimate strength of the cable, the conclusion arrived at 

 was, that a cable composed of homogeneous wire, calculated to bear 

 not less than from 850 to 1000 lbs. per wire, with a stretch of five- 

 tenths of an inch in 50 inches, is the most suitable for the Atlantic 

 cable. The following is the specification of this cable : — The con- 

 ductor consists of a copper strand of seven wires, each wire guaging 

 '048 inch, the entire strand guaging *144 inch, and weighing 3001bs. 

 per nautical mile, embedded for solidity in the composition known as 

 " Chatterton's compound." The insulator consists of gutta percha, 

 four layers of which are laid on alternately with four thin layers of 

 " Chatterton's compound," making a diameter of the core of '464 

 inch, and a circumference of 1*392 inch. The weight of the entire 

 insulator is 4001bs. per nautical mile. The external protection is in 

 two parts, the inner a padding of soft jute yarn, saturated with a pre- 

 servative mixture, and the outer a protective covering, consisting of 

 ten solid wires of the guage "095 inch, drawn from homogeneous iron, 

 each wire surrounded separately with five strands of Manilla yarn, 

 saturated with a preservative compound ; the whole of the ten strands 

 thus formed of the hemp and iron being laid spirally round the 

 padded core. The weight of this cable in air is 34 cwt. per nautical 

 mile. The weight in water is 14 cwt. per nautical mile. The 

 breaking strain is 7 tons 15 cwt., or equal to eleven times its weight 

 per nautical mile in water ; that is to say, if suspended perpendi- 

 cularly, it would bear its own weight in eleven miles depth of water. 

 The deepest water to be encountered between Ireland and Newfound- 

 land is about 2400 fathoms ; and the cable is known to be equal to 

 bearing 4" 64 times its own vertical weight in the deepest water in 

 which it will be placed. 



A paper by Captain Doty, of the Confederate States, On 

 Torpedos used by the Confederate States in the destruction of some 

 of the Federal vessels of war, and the mode of attaching them to the 

 rams, was communicated by Admiral Sir E. Belcher. A torpedo 

 having been attached to a small wooden steamer, an attack was made 

 against the Federal frigates, " New Ironsides" and " Minnesota.'* 

 These were so much damaged by the explosion, that, until docked 

 for repairs, they were unfit for further service. The sloop of war, 

 " Housatonic," was also attacked, and went down in eight minutes after 

 the explosion of the torpedo under her counter. It is asserted that a 

 vessel, properly constructed for the use and application of the torpedo 

 battery, and possessing superiority of speed, would prove a formidable 

 antagonist to send against a number of frigates armed with theheaviest 

 metal ; for it would, by advancing end on, present the least surface 

 to their fire, and always under the most acute angles. The torpedo 

 affords special advantages for fouling or disabling the screws or 



