lt that flood-lighting was installed to
protect them. By common consent this new phase was termed "protective
lighting." Soon after the entrance of this country into the recent war,
the U. S. Military Intelligence established a Section of Plant Protection
which had thirty-three district offices during the war and gave
attention to thirty-five thousand industrial plants engaged in
production of war materials. Protective lighting was early recognized by
this section as a very potential agency for defense, and extensive use
was made of it. For example, Edmund Leigh, chief of the section, in
discussing the value of outdoor lighting stated:

An illustration of our work in this connection is the case of
an $80,000,000 powder plant of recent construction. We arranged
to have all wires buried. In addition to the ordinary lighting
on an adjacent hill there is a large searchlight which will
command any part of the buildings and grounds. Every three
hundred yards there is a watch-tower with a searchlight on top.
These searchlights are for use only in emergency. Each tower
has a telephone service, one connected with the other. The men
in the towers have a view of the building exteriors, which are
all well lighted, and the men in the buildings look across the
yard to the lighted fence line and so get a silhouette of
persons or objects in between. The most vital parts of the
buildings are surrounded by three fences. In the near-by woods
the underbrush has been cleared out and destroyed. The trunks
and limbs of trees have been whitewashed. No one can walk among
these trees or between the trees and the plant without being
seen in silhouette.... I say flatly that I know nothing that is
so potential for good defense as good illumination and at the
same time so little understood.

Without such protective lighting an army of men would have been required
to insure the safety of this one vital plant; still it is obvious that
the cost of the protective lighting was an insignificant part of the
value of the plant which it insured against damage and destruction.

The United States participated for nineteen months in the recent war and
during that time about 400,000 casualties were suffered by its forces.
This was at the rate of about 250,000 per year, which included
casualties in battle, at sea, and from sickness, wounds, and accidents.
Every one h