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WHAT IS COLOR?
By RENE BACHE
THE BUREAU OF STANDARDS LABORATORY
Investigators using the spectrophotometer to measure the rednessof railway signal lamp glass.
L^iCK of definite color standards has
been the cause of so much trouble
that an effort is being made by
. the government to establish
-* them.'
Such standards for specifications are
urgently needed where colored fabrics
are concerned, for paints, and for many
other things that are bought and sold.
Even rosin, so largely used in the making
of varnishes, is priced largely according
to its color.
The attention of the Bureau of Standards
at Washington has been called especially
to the matter of cottonseed oil,
which for market purposes is graded
chiefly by color. It is used largely as
a substitute for olive oil, and for other
purposes which require that it shall be
bleached, and the bleaching process costs
money. The crude oil is yellowish red.
To take the color out of it means much
expense for chemicals.
Accordingly, the purchaser demands
an allowance for the amount of color that
has to be removed from the oil. So there
must be a color scale, to serve as a basis
for grading, and for this purpose the
refiners and dealers have depended during
the last twenty years upon glasses
which were supposed to represent standards
of color.
All of these glasses come from a single
manufacturer in England. They are
packed in boxes, each containing some
hundreds of glass strips of different
colors, neatly arranged in such a way as
to be kept separate and in due order
according to shades. Each refiner or
dealer has such a test box.
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