The Providence news. (Providence [R.I.]) 1891-1906, 1898-01-26
Standard Of Weights and Measures.

| TO make one SYSTEM compulsory II has
shown itself not unwilling to encourage
uniformity, for in June. 1885, an aot was
! passed which provided that copies or all
,hs standard Of weights and measures
should be prepared at Washington and o
full set delivered to tho governor or
each state in the Union. Upto that time,
brass yards and ellis furnished by the
county and state governments, and OF
very doubtful accuracy, or no accuracy at
all, were fastened to tho steps OF the court
houses In state ana county seats, and by
these the merchants In towns tested the
correctness OF their length measures.
Though standard measures we're made at
the Geodetic Survey and sent tn the
states according to the provisions OF the
act OF 1886. they were not used. The law
was repealed subsequently. and the stand
| ard whicn had remained I'm use by tine
executive department Of the government
became practically tho standard OF the
whole country. The primary units we're
tho original yard and the original pound.
But much CO.. fusion existed then In re-
gard to the relation Of our original meas
ures with those OF Great Britain. The
yard adopted was the distance tetween
two lines drawn upon the Iroughton
scales in 1918. But so delicate are the
adjustments required that tns length OF
this American yard has from time to tirpe
had different relations To the British yard.
These differences have been due TO the
temperatures at the times the compari-
son were mads, to degrees Fahrenheit
making an appreoiable differenos--from
the scientific stand point--in the length
of the two yirl measures.
Tle United states government contrib
utes annually something mors than $1,000
to tho support Of the International Bu-
reau of Weights ana Measures near Paris.
France. This bureau has had for its OBJ
ject the preparation of a new interna-
| tional standard meter and new ipterua-
tional standard kiloeramme. copies of
which have been male and distributed
| among the contributing governments. In
January, 1890, two standards IN ade at the
bureau and sent TO Washington were
brought to the Cabinet room at the White
House, and there the seals on the packages
were broken by the president of the
United States In the presence OF the sec.
retary Of state, the secretary of the treas
ury. and number OF scientific men.
They were then formally adopted, ana n
certificate from Benjamin Harrison was
writton TO the effect that they were origi-
mails or prototypes Of the original metre
and kiiogrsmme at Paris.
They were seat to the sealer of weights
and measures ut the Geodetic and coast
| survey where they are now kept. At the
survey the kiloRramme has been placed
in large glass case, tho doors Uf which
| hae been sealed by the superintendent OF
the survey. ana no one is allowed to open
them. The prototype CT the metre In or
dinary use Is also very carefully kept
and handled, although it is not under
soal. 1t Is heavy bar OF an alloy of
platinum and iridium and cost $500. 1t
is not flat. as most measures are. and a
cross section Of Ii would look not unlike
two flat-topped letter VS.. one inverted
en- the OTHER. The line Of measurement
is at the top of one of the VS.. Tho OBJ
ject Of this is 10 have the surface from
which tho measurement Is taken as near
as possible to what is known as tho
neutral axis Of the bar. This destroys
the possibility Of increase or diminution
in length by the infinitely small arc
which might be formed In handling the
bar. There are two bCrpished spots
upon which the limits Of the metre can
be very family distinguished. The lines
are finer many times than hairs
breadth.
There Is most wonderful scale by
which weights are adjusted for mer
chants. 1t TO- kept under lock and Key
in flreproof room in the basement OF the
old Butler house adjoining the main
building of the Goedetic survey. Ii is
one OF the most accurate scales In the
world So delicate are the adjustments
required that the temperature Of the body
OF the operator is considered to impair
the efficiency OF the instrument. There
fore the observer stands at q distance of
fifteen or sixteen feet from the scale
when the weighings are being made.
operating the instrument by series Of
brass rode. The observer makes his read
ings through q telescope which is d.
rected upon two ivory scales at the top of
the balance. ono OF these scales is perma-
nent and the other is attached to tho bal
ance. A weighing having boen made on
ore side, tho brass rods ars manipu lated
and. by simple but most ingenious and
smooth-running mechanism, the weight
is transferred from one side TO the other
An idea of tne accuracy of this wonder
ful balance may be had from. n statement
recently made ty Professor Mendenhall TO
the Academy OF Sciences. lie described
weighing OH this scale with two standard
kilogrammc weights. The weights were
lrst plaosd IN ORC of the balanoe stands.
side by slde. aud weighed. Afterward
they wera weighed In tho same pan ana
under the same conditions. but In this
case one was placed on top Of the other.
The two weishings differed. Placed one