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

ACQUIRiNG NATIONAL STANDARDS
The work begun by Dr. Wolff in photometry had been turned over to
Mr. Edward Hyde, who was studying a number of photometric standards
acquired from the Reichsanstalt. Among his problems was the ratio of the
candle to the Hefner amylacetate lamp which he had determined as 1 to 0.88.
In preliminary tests the Hefner lamp, generally accepted abroad as a pri-
mary photometric standard, proved to have so many defects as to be unfit for
measurements of the accuracy he hoped to attain. The Bureau had there.
fore established a temporary standard by arbitrarily assigning a mean value
for a number of ordinary 16.candle commercial carbon filament lamps. By
means of potentiometers, current and voltage to the lamps could be kept
constant to within one-hundredth of 1 percent while making comparisons.
Thus very accurate comparisons and very exact copies of standards were
possible.
The Bureau had recently requested a number of lamp manufacturers
in this country to submit carefully rated samples of their 16.candlepower
lamps for comparison with the Bureau standards. They were found to vary
from 15.4 to 17.6 candlepower, averaging 16.48 candlepower or about 3
percent high. This fairly close agreement resulted, the Bureau learned, from
the manufacturers' use, as standards, of incandescent lamps rated at the
Reichsanstalt.
But these were "model" lamps that had been sent to the Bureau. Sub-
sequent testing of the commercial product was to reveal wide variations in
their performance. Meanwhile, until the Bureau had devised methods for
testing commercial lamps on a large scale, it could only verify those used as
industrial standards or make special investigation of any particular lamps
submitted to it. Better lamp and light standards and many other aspects
of photometry remained to be explored, and this work would be pressed when
the section moved into its new quarters.
The chemistry division, not yet organized, was to be headed by Dr.
William A. Noyes, who had come to the Bureau from Rose Polytechnic In-
stitute, where his starting salary had been the highest ever offered to a
professor there. Through the courtesy of Professor Remsen, he was now
at the Johns Hopkins University making a study of chemical standards needed
in research laboratories, his quest interrupted by occasional trips away to
supervise sugar analyses at the customhouses. His associate, Dr. Stokes,
appointed from the Geological Survey, was at Dr. Wiley's Bureau of Chem-
istry in the Department of Agriculture, investigating equipment and measure-
ment problems of its chemists with which the National Bureau of Standards
might assist. As soon as Noyes and Stokes moved into their new laboratories
and acquired assistants, they would begin much needed work on the standard-
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