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

466 THE NEW WORLD OF SCIENCE (1946-51)
11.7, as the basis for a new pH scale. With certified samples of these sub-
stances, laboratories were at last provided with means for checking their own
scales and maintaining uniformity of procedure.103
A series of important postwar projects began shortly after an Army
plane, the XS—1, exceeded the speed of sound (760 miles per hour at sea
level) for the first time on October 14, 1947. At the request of the National
Advisory Committee on Aeronautics and the Navy Department, search was
made for engineering and operational data on air turbulence and its effects
at supersonic speeds.
The inauguration of supersonic flight also led to new work at the
Bureau in high temperature ceramics and the development of a new high
temperature ceramic coating, for the turbine blades of jet engines and the
liners of rocket motors. Significant studies were conducted on combustion
at high altitudes in jet, turbojet, and ramjet engines and thrust augmenters.
With special instruments devised for the tests, new measurements were made
on rubber and metal reactions at extremely high and low temperatures. But
much remained to be done. Jet propulsion and supersonic flight called for
almost total revision of data on fuels and the extension of many measure-
ments to higher temperatures, pressures, and velocities.'04
At the other extreme was a new phase of the Bureau's low temperature
work, begun with the acquisition of an improved helium liquefier in
for a program of basic research in superconductivity.'05
The phenomenon of superconductivity—the disappearance in certain
materials of resistance to an electrical current at very low temperatures—
seemed a particularly challenging field in low-temperature physics, its spectac-
ular effects giving promise of a basic insight into some of the fundamental
properties of matter. Several lines of investigation were started, including
studies of the anomalous properties of liquid helium II, an analogue of
103 NBS Annual Report 1948, pp. 219—220: Annual Report 1950, pp. 4-6--47.
An interesting standard sample was the 15 gallons of very pure isooctane (2,2,4-trimethyl-
pentane) and normal heptane prepared by the Bureau in the late 1940's and put up in
ampoules for the American Petroleum Institute as ultimate primary standards for the
octane rating of gasolines sold throughout the country. Subsequently the Phillips
Petroleum Co. prepared good batches of both isooctane and heptane as working stand-
ards, but the Bureau ampoules, known as "the gold-plated standards," are still main-
tained at the API research laboratory at Carnegie Institute of Technology to settle
disputes. Interview with Thomas Mears, Sept. 15, 1964.
NBS Annual Report 1948, pp. 221, 223; Annual Report 1949, pp. 15—16, 18, 49; Annual
Report 1950, pp. 8, 58, 64, 66; Annual Report 1951, pp. 24, 43. See also LC832,
"Bibliography on gas turbines, jet propulsion, and rocket power plants" (1946)
LC872, "Gas turbines and jet propulsion" (1947); C482 (1949), superseded by C509
(1951), on the same subjects.
'o' For earlier note on superconductivity, see ch. V, p. 247.