Measures for Progress: A History of the National Bureau of Standards

RESEARCH ZN CRiTiCAL MATERIALS 419
as some called it. Early in the war the Joint Chiefs of Staff called for a
practical means of aiming reflected flashes at potential rescue craft, both
planes and ships, as part of the equipment in liferafts and boats. A member
of the Bureau staff at the time, L. L. Young, hit on the rearsight method of
aiming mirror flashes, employing reflections from both its front and rear
surfaces immediately around a sighting hole in the center of the mirror.
Incorporating suggestions made by General Electric, which undertook their
manufacture, more than a million of the mirrors, of tempered glass with
a surface of vaporized aluminum film, were produced for the air and trans-
port services.149
The optics division took part in or carried out alone more than
30 separate investigations, most of them under NDRC auspices. Dr. Briggs's
comprehensive report of war research indicates that quite apart from the
special groups working for the Manhattan District, on the proximity fuze,
on guided missiles, and in radio propagation, each of the other divisions
was engaged in as many or more projects as optics. Enumeration of the
projects, let alone a description, is beyond the scope of this history. Only
a few representative studies can be mentioned.
A laboratory tool of limited interest until the war was a magnetic
balance for inspecting certain kinds of steel. Devised by a member of the
electrical division in 1.932, it was modified by a Bureau chemist 5 years
later for gaging the thickness of metal, paint, or enamel coatings on nickel,
steel and other metals, making possible nondestructive testing of the coatings.
Only a few had been made by the American Instrument Co., under the name
Magnegage, until the wartime rash of substitute materials and the necessity
of plating made the gages important in many industries, in order to expedite
acceptance of military supplies and conserve scarce metals by avoiding the
use of unnecessarily thick coatings. Arsenals found the Magnegage invalu-
able for measuring the thickness of the chromium in the lands and grooves
of large caliber guns."°
Expansion of Bureau investigations in aviation fuels, lubricants, and
motor fuels resulted in greater knowledge of their composition and better
control in their production. Many of the war plants making aviation fuels
had no previous experience in quality control procedures, and for them
the Bureau provided the necessary calibration of primary and reference
standard fuels, based on specifications prepared for the American Society
for Testing Materials (ASTM), and of "referee" fuels to ensure even quality
in production.
John A. Miller, Men and Volts at War (New York: McGraw-Hill, 1947), p. 104;
NBS War Research, pp. 110—Ill.
150 RP532, "A magnetic balance * * 'p" (Sanford, 1932); RP994, "Magnetic methods
for measuring * * * coatings on nonmagnetic base metals" (Brenner, 1937) ; RP1O81,
4' * coatings on iron and steel" (Brenner, 1938); NBS War Research, p. 60.