ven
temperature, and correction was made for barometric influence. Though
of high scientific interest, the apparatus appears to have failed at the
time from its very sensitiveness; the waves on the surface of the sea
having a greater disturbing action on its readings than the change of
depth. Siemens took a great interest in this very original machine, and
also devised a form applicable to the measurement of heights. Although
he laid the subject aside for some years, he ultimately took it up
again, in hopes of producing a practical apparatus which would be of
immediate service in the cable expeditions of the s.s. Faraday.

This admirable cable steamer of 5,000 tons register was built for
Messrs. Siemens Brothers by Messrs. Mitchell & Co., at Newcastle. The
designs were mainly inspired by Siemens himself; and after the Hooper,
now the Silvertown, she was the second ship expressly built for cable
purposes. All the latest improvements that electric science and naval
engineering could suggest were in her united. With a length of 360 feet,
a width of 52 feet, and a depth of 36 feet in the hold, she was fitted
with a rudder at each end, either of which could be locked when desired,
and the other brought into play. Two screw propellers, actuated by a
pair of compound engines, were the means of driving the vessel, and they
were placed at a slight angle to each other, so that when the engines
were worked in opposite directions the Faraday could turn completely
round in her own length. Moreover, as the ship could steam forwards
or backwards with equal ease, it became unnecessary to pass the cable
forward before hauling it in, if a fault were discovered in the part
submerged: the motion of the ship had only to be reversed, the stern
rudder fixed, and the bow rudder turned, while a small engine was
employed to haul the cable back over the stern drum, which had been used
a few minutes before to pay it out.

The first expedition of the Faraday was the laying of the Direct United
States cable in the winter of 1874 a work which, though interrupted by
stormy weather, was resumed and completed in the summer of 1875. She
has been engaged in laying several Atlantic cables since, and has been
fitted with the electric light, a resource which has proved of the
utmost service, not only in facilitating the night operations of
paying-out, but in guarding the ship from collision with icebergs in
foggy weather off the North American coast.

Men