therefore, to undertake immediately the changes in existing buildings,
the erection of new buildings, the installation of railway tracks,
laboratories, and the plumbing, heating, and lighting plant, etc. This
work was carried on with unusual expedition, under the direction of the
Assistant Chief Engineer, Mr. James C. Roberts, and was completed within
a few months, by which time most of the apparatus was delivered and
installed.

One building (No. 17) is devoted to the smaller physical tests of
explosives. It was rendered fire resistant by heavily covering the
floors, ceiling, and walls with cement on metal lath, and otherwise
protecting the openings. In it are installed apparatus for determining
calorific value of explosives, pressure produced on ignition,
susceptibility to ignition when dropped, rate of detonation, length and
duration of flame, and kindred factors. Elsewhere on the grounds is a
gallery of boiler-steel plate, 100 ft. long and more than 6 ft. in
diameter, solidly attached to a mass of concrete at one end, in which is
embedded a cannon from which to discharge the explosive under test, and
open at the other end, and otherwise so constructed as to simulate a
small section of a mine gallery (Fig. 2, Plate VI). The heavy mortar
pendulum, for the pendulum test for determining the force produced by an
explosive, is near by, as is also an armored pit in which large
quantities of explosive may be detonated, with a view to studying the
effects of magazine explosions, and for testing as to the rate at which
ignition of an explosive travels from one end to the other of a
cartridge, and the sensitiveness of one cartridge to explosion by
discharge of another near by.

[Illustration: PLATE VI.