NATURAL PHILOSOPHY. 149 



On the Polar Decomposition of Water ly Frictional and Atmospheric Elec- 

 tricity, by Professor Andrews. The author having drawn attention to the fact 

 that water had never been decomposed by the action of the common friction 

 electricity, so as to collect the gases and exhibit them at the opposite poles, 

 stated that the cause of the failure of the experiment was the solution of the 

 gases in the mass of the liquid. By fusing platina wires in thermometer tubes 

 this difficulty is avoided, and the gases may be then obtained and collected 

 with the same facility as in ordinary eudiometric experiments. By arranging 

 a series of such tubes, the operations may be almost indefinitely repeated. 

 On raising an electrical kite, the author succeeded in obtaining the polar de- 

 composition of water by atmospheric electricity. The observations were made 

 in fine weather, when the atmosphere was not usually charged with electricity. 

 Although the gases were easily collected and measured, from the delicate form 

 of apparatus employed, the quantity of water decomposed in this case amounted 

 only to one 700,000th of a grain in the hour. Proc. British Association. 



Bonelli Experiments in Electric Communication. Experiments have recently 

 been made in Sardinia by M. Bonelli with a view of using the common iron 

 railway track as a conductor of electricity for telegraphic purposes. It is thus 

 proposed to convert railways into telegraphic lines and make the electro-mag- 

 netic machine an attachment and servant to the locomotive. In an experiment 

 reported, it is stated that a locomotive running at full speed repeatedly ex- 

 changed messages with the station whence it started. The questions and 

 answers were varied and repeated during numerous trips, without a single 

 fault, and the inventor finally announced his complete success to the Minister 

 of Public Works at Turin from a car running at the rate of a mile in two 

 minutes. 



THE MEDITERRANEAN SUBMARINE TELEGRAPH. 



The work of completing the Mediterranean Electric Telegraph, which will 

 ultimately furnish a communication between London, Egypt, and India, has 

 been vigorously pushed during the past year. It will be remembered that last 

 year* 110 miles of cable were laid down between Spezzia and the most north- 

 ern point of Corsica. For this section of the line 90 miles of cable, weighing 

 eight tons to the mile, and containing six insulated wires, were required ; the 

 remainder was taken to the straits between Corsica and Sardinia, and twelve 

 miles were lard down there, the communication having meantime been com- 

 pleted along the island of Corsica by land. The communication being now 

 complete from London to Cagliari, in the south of Sardinia^ and the line from 

 Algiers to Cape Bonan, on the African coast, having been opened January, 

 1855, nothing is now wanted to complete the communication between Lon- 

 don and Algiers but a submarine cable from Cape Spartivento, adjoining 

 Cagliari, to Bonan. This cable is already manufactured, and is the largest and 

 heaviest, beside being the longest, ever laid down. It is 150 miles long, 

 each mile weighing 8 tons, and the whole cable weighing 1.200 tons. This 

 is exclusive of 12 miles of lighter cable sent with it to avoid ah 1 chance of 



* See Annual of Scientific Discovery for 1855, pp. 166-163. 



