624 Original Articles. | Oct., 
ON THE CONSTRUCTION AND MECHANICAL PROPER- 
TIES OF SUBMARINE TELEGRAPH CABLES. 
By Witu1am Farrparen, C.E., LL.D., F.R.S. 
Twenty-Four years have now elapsed since Professor Wheatstone 
suggested to the Select Committee of the House of Commons on 
Railways, the construction of a submarine telegraph between Dover 
and Calais. Since that time 11,000 miles of cable have been laid, 
only a little more than one-fourth of which can be said to be in a 
working conditon; amongst the unsuccessful attempts being the 
Atlantic cable, measuring 2,200 miles; the Red Sea and India 
Telegraph, of 3,499 miles, and sundry shorter ones, measuring col- 
lectively about 2,300 miles. To account for these misfortunes is a 
work of some difficulty, owing to the many causes which may affect 
the integrity of the insulation, or the continuity of the conducting 
wires. The 8,000 miles of failure have not been, however, wholly 
lost. They have been the means of accumulating a vast amount of 
experience, and have suggested remedies for the inevitable difficulties 
which have to be encountered, now as before, both in the manufacture 
and in the paying-out of deep-sea cables. 
There are two descriptions of cables required for marine construc- 
tion: one for shallow water, where, owing to the lability of injury 
from ships’ anchors, or the abrasion against rocks or gravel, it is 
necessary for the insulated wire to be surrounded with an extra strong 
covering of wire and hemp saturated with pitch; and the other for 
deep-sea purposes, in which case, as the cable when once laid is sup- 
posed to lie perfectly quiescent at the bottom of the ocean, no more 
strength nor protection is needed than will shield the wire and its 
insulating coating from injury during the paying-out. Respecting the 
_ shallow-water cables, in which category we class the line between 
Dover and Cape Grinez, laid in 1851 ; the line from Dover to Ostend, 
laid in 1853; the one from England and Hanover, 280 miles long, 
laid in 1858; one between Folkestone and Boulogne, laid in 1859; 
and one between England and Denmark, 350 miles long, also laid in 
1859, all the above are the property of the Submarine Telegraph 
Company. In addition to these, there are: several others which may 
come into the same class, such as the lines between England and 
Holland, and the Channel Islands cable, laid between this country and 
Alderney, Guernsey, and Jersey, in August, 1858. 
Amongst the most important of the deep-sea cables is that of the 
Atlantic Telegraph Company. This company obtained an act of 
incorporation in 1854, which conferred, amongst other privileges, the 
exclusive right of landing cables on the coast of Newfoundland, or 
the adjacent islands, for a term of fifty years. The company also 
obtained a grant of 14,0007. per annum from the British Government, 
and a similar one from the American Government, so long as the line 
was in working order. 
Upon these guarantees and privileges the company was formed, and 
