is also different. Since the last experiments were carried out against
her, however, measures have been taken to make her as far as possible
the counterpart, so far as under water arrangements and coal protection
are concerned, of a modern ship of war.

At the last attack, the Whitehead was directed against the after part of
the hull on the port side in wake of the boilers. During the present
series of experiments the old ship was assailed on the same side, but
directly amidships, in the neighborhood of the engine room. As no steam
was got up in the boilers, the effect of the jar upon the steam pipes,
glands, and feed connections remains a matter of speculation. So far as
the consequences of the burst upon the structure of the hull itself is
concerned, every care was taken to make the ordeal as complete and
instructive as possible. The wing passage, which has a maximum diameter
of 3 ft. diminishing to a point, was left empty, although at the former
experiments the lower portions were filled with coal. But behind this,
and at a distance of 8 ft. from the bulkhead, a longitudinal or fore and
aft steel bulkhead 3/8 in. thick had been worked to a length of 61 ft.,
and, with the coal with which the intervening compartment was packed,
formed (as in recent armorclads) a solid rampart, 20 ft. high, for the
defense of the engine room.

The height of the double bottom between the outer and inner skin plating
is 2½ ft. The watertight compartments were divided into stations by
means of vertical lightening plates pierced by three holes, and in order
to make them, as far as was practicable, resemble the bracket frames of
a modern armorclad, the center of the plates was cut away so as to leave
a single oval hole instead of the three circular holes. In view of the
differences of opinion which exist on the part of experts on the subject
of under water protection, the officers of the Vernon had determined to