ss of two tons through the back wall of the building, and
spent its force against a tree-trunk. There was no explosion, and
nothing happened, which was something of a miracle; but what impressed
me was that these four men stood still, not from courage, but because
they were frozen with fear!

[Illustration: "A SWIFT, HEAVY CAR WAS PLUNGING TOWARD THE OPEN DOOR."]

While there is danger in every step of dynamite manufacture, it appears
that the center of peril is in the nitrating-house, where the fresh
glycerin is mixed with nitric acid, or, more correctly, is nitrated by
it. This operation takes place in a great covered vat about which are
many pipes and stop-cocks. A man stands here like an engineer at the
throttle, watching his thermometer and letting in fresh glycerin. These
are his two duties, and upon the right performance of them depends the
safety of the works. Every hour he must let in some seven hundred pounds
of glycerin upon the deadly acid, and every hour he must draw off some
fifteen hundred pounds of nitroglycerin and let it go splashing away in
a yellowish stream down the long, uncovered trough that leads to the
separating-house yonder. From this separating-house runs another trough
to the freezing-house, and a third to the distant mixing-house. These
three troughs inclose an oblong space, at the corners of which stand the
nitrating-house, the separating-house, and the freezing-house. In each
one of these, at any hour of the day, is a wagon-load of pure
nitroglycerin, while in the three troughs are little rivers of
nitroglycerin always flowing.

The arrangement of buildings in this part of the works makes clearer
what was done at the nitrating-house by a certain Joshua Plumstead in
the recent explosion. Joshua is a veteran at dynamite-making. He has
worked at the nitrating-vat for twenty-five years, and has probably made
more nitroglycerin than any one man in the world. He has been through
all the great explosions; he has seen many men killed; he has stood by
time and again when his own nitrating-vat has taken fire; and yet he
always comes through safely. They say there is no man like Joshua for
nerve and judgment when the demons of gas and fire begin to play.

This explosion took place at the freezing-house, which is the one place
in all the works where dynamite is never expected to explode. Yet it
_did_ explode now, with a smashing of air and a horrible grinding
underfoot that stifled all things in m