The Washington times., 1904-07-03

SUITABLY aged before testing. Its m
dlca tons are Liable TO change with time:
Where thermometers have been placed
under the official seal OF the bureau for
at least six months preceding date OF
test, the letter A IS engraved on the
stem Immediately after the 3. S. GER
uficasjOn number
The Value of Accuracy.
The testing Of promoters. the instru-
ments used IN determining high Tempera-
lures. is also being carried on on a large
scale. Promoters are used extensively
in the manufacture Of steel. porcelain
and glass. where it is very important
maintained. Inaccurate promoters, OF
course, defeat this aim
Manufacturers send them TO the
bureau in large numbers. In cooling
steel casting, arnor plate and the IKE
variations in temperature viii result N
cracks or other damage and while the
cooling process is going on the operator
watches closely TO see that nothing OF
this sort happens. With standardized
pyrometer he can be absolutely assured
he is right. The same thing is true n
glass and porcelain manufacture. where
the ability TO repeat beautiful effects IN
cOloring and exterior finish depend fun
damentally upon the ability to reproduce
the exact conditions or temperature that
obtained in the first instance.
Recently the bureau has used one OF
its experts, r. j. Bates, IOE the 4ItdnllS
Department for the purpose Of pursuing
experiments as to the accuracy OF the
instruments used in determining he
amount of saccharine matter IN raw
sugar. The Government collects duty
of about IL cents q pound on sugar, the
duty varying with the degree or the
sugars purity. Zach year this tariff
amounts TO between $5o.000,000 and $780,
100000
Mistake Means Millions
The relative purity Of the sugar is as
certained by means OF an instrument
called the saccharimeter. a form OF the
polariscope. IT depends for its effective
ness upon the accuracy with which il
measures twist Of the direction of vibra-
ton of polarized light. and IS. necessari-
". of delicate construction and opera
ton The error OF a mill IN the duty on
pound of sugar means an annual dit-
ference to the Government or over S-,Vov,-
coo. Mr.. Bates. therefore, has been try
ing to see 10 IL that the saccharimeteTs
used are very accurate.
The bureau has been much hampered
in the mast for lack 3f space and con-
venIence for testing. but these wiz be
obivated in large measure when II has
completed its removal 10 the new oulld-
ings.
ent time 10 compare base-meaSuring ap-
paratus and steel tapes, but the facili-
ties are such that the best results are
only attained at the expense OF great
The tunnel connecting the physical
and mechanical laboratories will be 1T
ted out with facilities for comparing this
kind of apparatus. This tunnel viii be
10 feet long. seven feet wide, and eight
feet high. and facilities viii be prOvid-
ed for comparing tapes up TO nifty
meters in length. and t, lay out base
of the same length with an error not
greater than one part IN two or three
million. over which baSe-mCasurinE APP
paratus may be tested Means Will also
be provided for raising the tempera-
ture TO, say. 80 degrees centigrade. and
lowering TO 10 degrees centigrade. for tie
determination of temperature coefhcientS
of apparatus submitted.
Covers a Broad Field.
Under the administration Of Dr. STRAIT
ton the activities OF the bureau have
been extended over a broad field. It's
experts have already been called upon
TO testify in a case at law, in which
It became a question whether a camera
which had been used TO take a photo
graph was accurate or otherwise. The
lens OF the camera was subjected 10
scientific tests and IL was possible 20
swear with positiveness that II answered
every requirement of essential ac-
curacy.
Much OF the apparatus needed has had
TO be constructed. as Il was invented by
the scientists whose Investigations are
constantly in progress. Scientific. in
vestigation and research constitutes a
large part OF the bureaus work, and
questions which 10 the lay mind would
seem far removed from the determine
ton Of accurate standards OF weights
and measures and degrees Of tempera-
tuFc have been succe ssfully solved. The
! bureau Is doing much for American
manufactures and Tor American science;
! in it's now quarters there can be no
doubt that its useful activities viii DO
largely increased.