ATLANTIC TELEGEAPHY. 
549 
This wrapping of jute is surrounded by ten wires manufac- 
tured from homogeneous iron. Each separate wire being itself, 
in the first instance,, covered with tarred Manilla yarn, by which 
the iron was protected and the specific gravity of the mass 
lessened. By a very ingenious arrangement, which our space 
will not allow us to describe, the ten wires covered with the 
arred manilla hemp are spirally wound around the core, and 
the deep-sea cable is completed. The section and side view 
of the electric cable will be fully understood by reference to 
figs. 4 and 5. As the shore end of any cable is more exposed 
to the action of the waves than those parts are which remain in 
a state of rest at the bottom of the deep sea, it becomes neces- 
sary to give this portion a greatly increased degree of protec- 
tion. Fig. 8, PI. XXI., which is of the exact size of the shore 
end of the Atlantic cable, will fully illustrate the conditions of 
this portion. This shore end is the largest ever yet con- 
structed. The core was formed by the main cable, which was 
wrapped with a serving of yarn to a size sufficient to receive 
around it twelve strands of iron wire, each strand being com- 
posed of three galvanized iron wires, each of which being nearly 
a quarter of an inch in diameter. The weight of the com- 
pleted shore end was nearly twenty tons to the mile. Its 
diameter is 2^ inches, but at its junction with the main cable 
it is made to taper down to the size of the latter by a gradual 
diminution in diameter extending over- 500 yards. This 
shore end was laid out for about twenty-eight miles from the 
coast of Yalentia Island, when it reached water of the depth 
of 100 fathoms. From Hope^s Content, Newfoundland, about 
eight miles of shore cable only would have been required. 
The weight of the deep-sea cable — according to the Com- 
pany's statement — in air was 35 cwt. 3 qrs. per nautical mile 
of 2,028 yards. Its weight in water, 14 cwt. to each nautical 
mile, or equal to eleven times its weight in water per knot ; 
that is to say, it will bear its own weight in eleven miles deep 
of water. Its breaking strain was 7 tons 15 cwt. The length 
of cable shipped was 2,300 nautical miles ; the actual distance 
from the point of departure, Yalencia, on the west of Ireland, 
to the point HearPs Content, in Trinity Bay, Newfoundland, 
on which it was to have been landed, being 1,670 nautical miles. 
The sections which are given (figs. 1, 2, 3, PL XX.) show 
that the greatest depth to be encountered was 2,400 fathoms 
(14,400 feet), a little less than 2| nautical miles. Mr. Saward, 
the Secretary of the Atlantic Telegraph Companjq has stated 
the case so well that his words are borrowed. 
The problem in the case ©f the Atlantic Telegraph enter- 
prise may be thus stated. Given a submarine telegraph core 
like that already described, constructed on the best known prin- 
