622 TRANSACTIONS OF THE 



managed by means of suitable chains by two firemen, one on each 

 side. The Franklin Institute has certified the utility of this 

 machine. 



Dr. Smith introduced Mr. Ellinger, who exhibited a hollow cru- 

 cifix of wood, carved richly with the Savior on the cross and other 

 figures. The work is attributed to the celebrated Benvenuto 

 Cellini. The hollow contained relics of several saints. 



SUBMARINE ELECTRIC CABLE. 



Mr. Meigs — The experiments of Franklin, in 17.52, were the 

 conduction of the electric fluid above water across the Schuylkill 

 and back, but never under water. In 1746 and 1747 the Royal 

 Society of London tried several interesting experiments. They 

 passed a single wire over London bridge, and took the ends to 

 the water's edge, and found that the electric fluid which was car- 

 ried over the bridge by the wire returned through the water. 

 They extended several thousand feet of wire above moist meadow- 

 land, and found the return circuit was by the land. They stretched 

 wire above land on the banks of the Thames, at a bend or two of 

 water; wire over the land in three or four places, and interrupted 

 by the water in line. A part of the land was very dry gravel, 

 but they found the return circuit was good through the land and 

 water. They did not try conduction under water. 



In October, 1842, at the fair of the Institute, Professor Morse 

 exhibited his insulated electric cable, laid under water from the 

 Battery to Governor's island, nearly one mile, and also to Mr. 

 Colt's submarine magazine, attached to the bottom of a brig lying 

 a proper distance from the Battery, and blew her up with it. 

 The American Institute awarded him its greatest premium for 

 this experiment — a gold medal — the first reward his genius had 

 gained for him. 



Ten years ago the world was startled at the idea of the fluid 

 leaving a wire on one side of water and going directly to another 

 wire on the opposite side of the water. Now we know little 

 about the rationale of the transmission of electricity, light, &c., 

 but the theory of propagation by wavy impulses is applied to 

 light, and by some to electricity. That the material in both cases 

 is present, and is only sensible to sight or feeling when put in 

 motion as the extending wave on water, &c. And by experiment 

 we know that the propagation of sound through water is four 

 times the velocity of sound through air, and, therefore, if the 

 impulse given could be extended as far as those of light and 

 lightning, we could send a sound from New- York to Liverpool 



