THE 
TECHNOLOGIST: 
A RECORD OF SCIENCE. 
piacere 
OCTOBER, 1866. 
—_0o-=—- 
DEEP SEA TELEGRAPH CABLES COMPARED. 
BY N. DUDOT, ESQ., C.E. 
HE cable of Allan, for example, is constructed on 
quite a different principle to other submarine cables, 
inasmuch as the whole of its effective strength and resist- | 
ance is within the conducting power, or core, which is . 
rationally combined, rendered efficiently strong, resistant, 
and comparatively inextensible, whilst that is not the case 
with the ordinary construction of wire-covered cables, 
where strength is sought on the outside of the conductor, 
but adds insufficiently to it. Hence it becomes inefficient, 
and does not answer the intended purpose. 
It does away with the necessity for outside spiral wires, 
and therefore is smaller, lighter, more flexible, and yet con- 
siderably stronger and more effective than all other kinds 
of submarine cables. [Ht is, in fact, so far superior in every 
way, that, for the Atlantic or other deep seas, it certainly 
ought to be adopted in preference to any of them, whilst 
it is more cheaply constructed, more durable, more easily, 
safely, readily, and economically handled, carried, shipped, 
paid out, submerged, laid, and raised if required. 
Its inextensible core, wherein the necessary conducti- 
bility for the distance is combined with the greatest 
amount of relative strength possible to be attained, 
counteracts tension, and consequent injury to the insu- 
lating medium, retaining, therefore, all its original strength 
NEW SERIES.—VOL. I. K 
