104 ANNUAL OF SCIENTIFIC DISCOVERY. 



if any people shall ever carry it from our Atlantic shores across the 

 continent to the coast of the Pacific Ocean, I feel the strongest convic- 

 tion that it will be accomplished by our countrymen ; when we may 

 obtain intelligence from China in as short a time as it now reaches us 

 from Europe." 



ON THE CONDUCTION OF ELECTRICITY THROUGH WATER. 



MR. BAKEWELL, at the British Association, stated the results of some 

 experiments on the conduction of electricity by water, made with a 

 view to prove that an electric current may be transmitted for a con- 

 siderable distance through unprotected wires immersed in water. A 

 thin copper wire, (No. 20,) 320 feet long, was stretched across a pond, 

 and two copper plates, ten inches square, to which wires were soldered, 

 were immersed to serve as conducting plates for the return current. 

 A Smee's battery of two pairs of plates was used ; and when the con- 

 nexion was made with a galvanometer on the opposite bank, a steady 

 deflexion of 30 was maintained, and a strong blue mark was produced 

 by a steel electrode on paper moistened with a solution of prussiate^of 

 potass in diluted muriatic acid. In this experiment the conducting 

 plates were placed close to the wire and on opposite sides of it, so that 

 the return current passed diagonally across the exposed wire. The 

 water in this case appeared to act as a conductor and as a non-con- 

 ductor at the same time, in proportion to the surfaces exposed to its 

 influence. In the next experiment the wire was doubled, and a cur- 

 rent of electricity from the same battery was transmitted through the 

 wires, both being immersed in the water. In this case the deflexion 

 of the needle was more powerful, and it continued steady at 45. 



SPEED OF THE MAGNETIC CURRENT. 



A LONG experience of the Coast Survey, with some different lines of 

 telegraph, establishes the fact, that the velocity of the galvanic current 

 is about fifteen thousand four hundred miles per second. The time of 

 transit between Boston and Bangpr was recently measured, and the 

 result was, that the time occupied in the transmission was one hundred 

 and sixtieth of a second, and that the velocity of the galvanic ^ current was 

 at the rate of sixteen thousand miles per second, which is about six 

 hundred miles per second more than the average of other experiments. 



SUBMARINE TELEGRAPH BETWEEN ENGLAND AND FRANCE. 



THE project of constructing a submarine telegraph between England 

 and France, across the Strait of Dover, unsuccessfully attempted in 

 1850, has been again undertaken during the past year ; and, aided by 

 experience, has been fully accomplished. The line or cable at present in 

 use is much more substantial than that formerly employed ; and was 

 constructed in the following manner : Four copper wires, known as 

 the 16 wire gauge, each encased in a covering of gutta percha, of a 

 quarter of an inch in diameter, constituted the first layer. These 



