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

460 THE NEW WORLD OF SCIENCE (1946-51)
Dr. Condon of the Bureau and Secretary of the Treasury John F. Snider, right, demon-
strate the NBS electronic currency counter with stacks of worn-out $1 bills.
The assembly on top of the cabinet consists of the turntable and feeding mechanisms
and the phototube-light-mirror system. The cabinet houses a binary counter, control
circuits, and an air compressor.
by a magnetic field. The principle of Rabinow's magnetic fluid clutch had
application not only in computers but, with modifications. in servomecha.
nisms, automatic machines, and possibly even in automobile transmissions.85
The patent for the clutch, in accordance with Bureau policy, was assigned to
"the public interest." So great was that interest that within a year almost
2,000 industrial engineers visited the Bureau to get test data on the
invention
Another device that came out of the electronics division about the
same time was the NBS electronic currency counter, a sensing instrument
that automatically counted worn paper bills at the rate of 30,000 per hour.
The device instantly rejected packets of bills returned by banks to the Treasury
for burning that contained more or less than the 100 per packet required by
regulations. Since 6 tons of currency are redeemed daily—about $40 million
worth, mostly in $1 bills—it was estimated that use of the electronic counter,
NBS Annual Report 1948, pp. vii, 240; Annual Report 1950, p. 78. For the Bureau's
high-speed piezoelectric crystal clutch, a nonmagnetic type, also used in computers, see
Annual Report 1951, p. 74.
"Hearings * * * 1950 (Mar. 9, 1949), p. 490; correspondence with Jacob Rabinow,
M'iv 5, 1964.