122 A SAGA OF THE SEAS 
There was the same number—seven—of copper wires in 
the core as in the first cable, and they were bunched together 
as before, but the new wire weighed three hundred pounds 
to the mile compared with a hundred seven pounds before, 
and it was purer copper. ‘The insulation of gutta-percha and 
hemp was thicker and better applied than in the first cable, 
and the steel wires of the armored sheathing were tougher 
and larger. Much had been learned about making steel in 
the few years since the first cable, and a given size of wire was 
now much stronger than before. ‘The new cable would sus- 
pend eleven miles of itself in water without breaking, as com- 
pared to only five miles of the first cable—an important factor 
in paying out cable in a rough sea two or three miles deep. 
The aim in designing this new cable had not been merely 
to make a heavier and thicker cable, but to secure strength 
combined with flexibility. Dead weight of itself is a fault. 
The old cable, although relatively small, had been almost 
as heavy as a rod of iron. When paid out from a ship, it sank 
with a suddenness dangerous for breaking, especially if the 
ship gave a sudden lurch. ‘Thus in 1857, the first cable broke 
when the Niagara’s stern was tossed up on a wave just as the 
brakes were shut down. 
The relative lightness of the new cable when immersed in 
water was partly the consequence of encasing each of the 
steel sheathing wires in thick hempen yarn saturated with 
preservative. ‘Thus the cable looked like a manila rope; in 
fact, it was a combination of rope and metal. The purpose 
of this design was to protect the steel wires from rust due to 
exposure to air and water, and also to lighten the cable when 
in water. This precaution proved only partly successful, for 
the hemp decayed rapidly in the sea, exposing the steel to 
the water after a few months. 
The heavier copper wire used in the seven threads at the 
center of the cable—the wire that carried the messages—was 
