Evening star. [volume] (Washington, D.C.) 1854-1972, 1905-04-09
1rsr'ss ELECTRICAL
Standardizing Weights.

OIL Dr. whey OF tnS btpdlh-
ment, Is now doing some work there.
Standardizing Weights.
The work connected with weights and
measures is under Mr. L. A. Fischer of
Columbia University who was for many
years connected with the Office of standard
weights and measures. He is assisted by
L. G. Eoxton, University of Virginia; r. Y.
Ferner, University of Wisconsin; n. S. Os-
borne Michigan School of Mines, and II.
L. Smith. The work in the volumetric de-
partment of this division. like that of all
the other divisions. is remarkable for Its
extreme accuracy. Nowhere In any of the
work Is anything but distilled water used.
for any impurity in the water will affect
both the weight and volume of the final re-
suits Glass measures of the most delicate
sort are weighed on fairy balances. allow
ance being made for the temperature of
the scale case. the state of the barometer
and the humidity of the air. Distilled water
is run into the measures and the gradua-
tons on the glasses checked by readings
through microscopes. The measures are
then certified and sent off to do service as
standards in chemical laboratories where
research work is being done to manu-
| facturers who are turning out thousands of
| finely graduated measures for use in COM
mercial work all over the country.
The place is full of queer instruments,
each designed to measure and check soma
particular form of receptacle that in turn
| will be used as standard for making
| other measures. This first work has to be
| done with the greatest accuracy, so that
| error will not be perpetuated and multi
piled outside the bureau.
Perhaps the work easiest for an out
| slider to appreciate is that done in the
| scale room, where weights from all over
| the country are sent to be standardized
| and compared with the carefully guarded
| weights and measures kept permanently in
| the vaults of the bureau There Is SET
| of marvelously fine, god-plated standard
| weights kept under glass in the scale room
| for everyday use. But the real STANDARD
| weights and measures never leave the
! vault. One knows what the various bal
| anceS are after one Is told. But at hrst
! glance some of them look more like steam
! engines or rapid-fire guns than they do
| like scales. There is one big pair of scales
/ that took six men to lift on its pedestal.
Like all the other fine balances, it is in
| closed in glass case, the doors of which
! are opened only to admit the weights. This
| particular scale is of German manufacture,
and is a cheap one, costing only $500 1t
will weigh up to fifty pounds, and is fine
| enough to detect variation of one IN
I % 600 900.
lis scale pans are like big metal fingers
| with spaces between them. Wheels AMI
levers. operated outside the case, will pick
up the heaviest weights the scale is de-
| signed for and transfer them gently from
the little rolling carriage on which they
are placed outside the case, to the finger
like scale pans inside. From the time the
glass doors are closed and locked there is
no need for the operator to touch the
weights again or even to go near them.
All his readings made on the scale
through little micro telescope, and his
wheels and levers will 1uggle the weights
about inside the case, and reverse the
scale pans so that after the weighing Is
cone on one side 1t can be done again on
the other to check any variation in the Two
scale arms Other levers will drop pick
I'D little hair-like riders of platinum
wire from the scale arms, so that even
ffty-pound standard weight can be gagged
to the tenth part of milligram.
Prohibitive Labor Prices.
These big scales are by no means the
most delicate in the laboratory. There is
another pair costing about $1,000 that are
not yet set up, but which will be operated
by man in the next room through long
coupling rods, so as to entirely remove
the disturbing element of bodily heat from
the weighing operation. All the reading on
these will of course, be done through a
telescope But the operator will have just
as thorough control of his scales as though
he were standing WITHIN arm reach d
them.
Allied to the weighing devices IS the set
of delicate measuring machines where
by the measuring rods of the manufactur-
ers the universities and many of the gov
eminent bureaus are checked. All this work
has of course, to be done at constant
temperature Some of the measuring Is
done in the vaults, and a metal rod VIII
be kept in a heat-insulated case for two
weeks to absorb the exact temperature.
The scientist at the end of that time may
have to make several trips to get the MI
croscopic reading, staying only few min
utes each time, so that the heat of his