i88 
THE TELEGRAPH. 
ilnis giving an excess of 15 per cent, in the suspended part. 
The actual result shows that this represented pretty accurately 
the curve of the suspended cable. 
The dimensions of the cable were : diameter, 1J inch ; 
weight, 3,600 lbs. per knot in air, and 1,400 lbs. per knot in 
water. The total weight of 9^ knots, suspended in water, 
should therefore be 12,950 lbs.; as the modulus of rupture of 
the cable was 15,700 lbs., it could support 11 knots of its own 
length in water without breaking. The idea of raising the 
cable at a single point was, however, abandoned, and it was 
resolved to raise it up by degrees. Three steam-vessels, the 
Medway , the Great Eastern , and the Albany , were consequently 
fitted out with raising machinery, so that they might drag the 
cable at three different points, the Medway to the east and the 
Albany to the west of the Great Eastern . 
The raising-up machinery for the expedition was entirely 
new, and had been constructed to bear a greater strain than 
that of the preceding year. 
The grappling-iron, which was very strong, had five hooks 
instead of three. It was 3| feet high, and weighed 230 lbs. 
The upper ring turned on its axis, and the arms would bear a 
weight of 9 tons, without damage. Attached to this grapple 
was a chain 30 yards long, connected with a rope on board. 
This rope was of seven strands (fig. 127), each formed of seven 
smaller strands with a galvanized iron wire in its centre, 
surrounded with hemp. The total diameter of the rope was 
1| inches, and it would support 30 tons. The weight in air was 
10,000 lbs., and in water 7,500 lbs. per nautical mile. 
