88 ANNUAL OF SCIENTIFIC DISCOVERY. 



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had to be done in so little time, he offered to discuss the subject 

 at length at any time with those interested in the matter. Some 

 remarks were made, not only of approval, but the opposite views 

 which had been always entertained were now entirely removed. 



ASPHALTE TUBES FOR UNDERGROUND LINES. 



Of what material the tubes used to protect and form a subway 

 for underground wires shall be made, has long been an open 

 question. M. Collette, of the Netherlands Telegraph Administra- 

 tion, has submitted the following interesting facts with regard to 

 the employment of asphalte. 



In 1865, a trial line, nearly 3,000 yards in length, was laid in 

 asphalte tubes in the streets of Amsterdam. These tubes have 

 each an interior diameter of 3 inches (about 75 millimetres), 

 and are 7 feet (2 metres 134 millimetres) in length. They are 

 jointed to each other by the aid of muffles of short pieces of tub- 

 ing 4 inches in interior diameter, the interstices being run with 

 bitumen. The laying was executed without the least difficulty. 

 Only 6 copper wires, covered with a double coat of gutta-percha, 

 were, in 1865, introduced into the asphalte tubes ; but, 2 years 

 after, this number was augmented to 25 wires. It is from this 

 occasion that we have been able to ascertain that the wires with- 

 drawn from the t<ubes, after having been worked during 2 years, 

 were in such perfect condition that they were replaced with the 

 19 new wires. The asphalte tubes, since they were laid, have 

 3 times been uninjured by accidents which cast-iron tubes would 

 have been unable to resist, and, doubtless, in breaking, would 

 have injured the wires. 



Five years have elapsed since the laying in Holland of the first 

 line in asphalte tubes, and, hitherto, scientific men have not been 

 deceived in their expectations. Also the Netherlands Telegraph 

 Administration has not hesitated to follow the path dictated by 

 experience. In January of the present year a length of 10^ miles 

 of underground lines was laid in asphalte tubes. The maximum 

 number of wires introduced into tubes, having 3 inches internal 

 diameter, amounted to 40. 



The tubes are chiefly manufactured at Hamburg, and the prices 

 are as follows : for tubes 7 feet in length and 3 inches in diam- 

 eter, one dollar per length ; for those having the same length 

 and 2 inches in diameter, the cost per length, including muffles 

 for jointing, is about 75 cents. Tubes having other dimensions 

 have not yet been constructed in Holland. 



THE CHASSEPOT AND THE NEEDLE-GUN. 



An account is published in the "Birmingham Gazette " of the 

 two weapons which are in the hands of the belligerents on the Con- 

 tinent. The " Zundnadelgewehr," or needle-gun, of the Prussian 

 service, to which the victories of the Prussian arms in 1866 have 



