ENGINEERING. 



347 



Eastern Telegraph Company completed the 

 duplication <>t tln-ir lines from England to 

 lloml.ay in 1878. The Eastern Extension Tele- 

 graph Company also have just duplicated their 

 i, which extend the connection from 

 Bombay to Australia by way of Madras, to 

 IVnang in the Malay Peninsula, and to the 

 Indian islands. The last year also the 

 i-n Telegraph Company have been en- 

 gaged in laying their cable to the Cape of 

 Good Hope. This company entered into an 

 agreement with the British Government to 

 have the line down between Durban and Zan- 

 zibar by the end of July, 1879, and to have the 

 whole cable laid and in working order by the 

 end of the year. In consideration of an annual 

 subsidy of $17,500, the company gives the 

 priority to Government messages, and agrees 

 to transmit them over the cable, which shall 

 be capable of telegraphing fourteen words a 

 minute, at half the rate charged the public. 

 The British Government has also stipulated 

 for the right to take possession of the wires 

 and offices, or to allow any of the colonies so 

 to do, in the event of a war, rebellion, or other 

 public emergency, and to keep possession as 

 long as is seen fit, upon the payment of a rea- 

 sonable compensation. To guard against the 

 teredos and other mischievous insects which 

 have proved so injurious to the older cables 

 by eating into gutta-percha, the Cape cable is 

 covered with a brass wrapping, except in the 

 deep-sea portions, where these pests are not 

 found. The French Pouyer-Quertier scheme 

 includes two cables from Brest to New York. 

 This new line may partly find its motives in 

 the French national pride, but it furnishes, no 

 doubt, a promising investment for French capi- 

 tal, and may press the present lines hard in 

 competition for the whole English and Con- 

 tinental traffic, besides securing the French. 

 The cables were manufactured at Charlton, 

 England, in the workshops of Siemens Broth- 

 ers. On the 16th of November the American 

 end of the cable was landed at North East- 

 ham, Mass., on Cape Cod, from the steamer 

 Faraday. No ocean-cable had ever been con- 

 structed and submerged at so rapid a rate: the 

 line was completed and messages sent from 

 continent to continent seven months after the 

 French Government had granted the conces- 

 sion to the company. The insulation of the 

 wires was found to bo remarkably perfect. 

 A new cable has recently been put down be- 

 tween Germany and Norway, at the cost of the 

 German Government. This line was consid- 

 ered diplomatically, since the only telegraphic 

 communication between Germany and Scan- 

 dinavia has been through Denmark. It is a 

 three-wired line, and extends from Rornoe, an 

 island off the coast of Schleswig, to a point 

 near Arendal. All telegraphic traffic between 

 Norway and Germany, and the greater part 

 of the telegraphic correspondence with other 

 countries, except Denmark, England, and 

 France, will pass over the new wires and be 



taken away from the Danish lines. The cable 

 was manufactured by Siemens & Ilalske of 

 Berlin. Russia has submerged a short cable 

 across the Caspian Sea. The line is 150 miles 

 long, and extends from Cape Gurgian to Eras- 

 novodsk. By it telegraphic communication 

 is established between Tjikislar and Asterabad ; 

 so that messages from Tjikislar can be sent, by 

 way of Teheran, over the Indo-European line 

 to Tiflis. 



Among the projects of submarine cables is 

 one which promises to be realized at no distant 

 day, and which when accomplished will com- 

 plete the telegraphic circuit of the earth. This 

 is a cable to be laid from California to the 

 Sandwich Islands, and thence to China and 

 Japan. Cyrus "W. Field has obtained the ex- 

 clusive concession for such a cable from the 

 Government of the Sandwich Islands, and ex- 

 pects to receive similar privileges from Japan 

 and perhaps China. Japan has long been de- 

 sirous of electric communications as complete 

 as possible with the outer world, and even 

 China is awakening to the advantages of tele- 

 graphic intercourse. A still more ambitious 

 project has been talked of for a new cable be- 

 tween America and Europe. This scheme is 

 for a cable running from New York to Flores, 

 one of the Azores, whence two extensions will 

 be carried to the European Continent one to 

 France, England, and Holland, and the other 

 to Fayal, San Miguel, and Lisbon. The entire 

 length of cabling required to carry out this 

 plan would be 7,300 miles. 



Subterranean telegraph wires have been in 

 use for many years on the Continent of Eu- 

 rope, and are regarded with such favor in Ger- 

 many that they are being constantly extended. 

 At first employed only for shorter distances, 

 now several long lines are laid underground, 

 which appear to work successfully. In Eng- 

 land, however, where there are 10,000 miles 

 of underground wires, they do not seem to be 

 attended with the same success. W. H. Preece, 

 the electrician of the postal service, reported 

 lately that, while their cost was three or four 

 times that of overhead wires, their power of 

 carrying currents is only a third or a quarter 

 as great, and that the gutta-percha covering is 

 attacked by rats and mice, and eaten away by 

 an insect called Tempeltonia crystalling and 

 also injured by a fungus. The British public 

 approves the adoption of this system on ac- 

 count of the danger to passengers from the 

 elevated wires. The lines are carried through 

 the cities below ground. Probably in the open 

 country they would be less liable to destructive 

 attacks. 



A novel system of insulation for under- 

 ground telegraph wires, invented by David 

 Brooks of Philadelphia, is said to be open to 

 none of the difficulties which attend this mode 

 of telegraphy, and which have produced such 

 discouraging results from the subterranean 

 wires laid in Great Britain. If wires can be 

 well insulated and protected from destructive 



