The Savannah morning news. (Savannah, Ga.) 1900-current, 1900-10-24

the Instruments aud the weighing
l. Done Prom Afar-Thc standard
KiloRramme aud Metre other
standards Urgently Needed.
From the New York sun
In the W1Edowless basement room. origi-
nally built FOR "a coal vault o. an old
mansion near the National Canuol IN
Washington is mounted the most delicate
pnir Of scales Ia the United states To
these scales is intrusted the work u DO
Ing the governments wcighiag They are
part of the equipment Of the Treasury De
partmcnrs Bureau Of weights and Meas.
ures which is attached 20 tho coast sur
tey. though why this should be- 30 nobody
has ever adequately explained
So delicate are these scales that they
viii weigh accurately a ten-mlllionth part
OF gram. They are so sensitive that tho
warmth given OF hy the body Of per-
aon approaching them near enough 20
open the glass case or 70 shit the weights
would expand the balance arms and pro-
duce an aDpreciable error IN tho results.
Therefore they have been so constructed
y tttAA N'Afa AAAh We Nlff.f tAfsA AN n AiHAAAtN'
| ~ twenty feet 10 f. not necessary 10 open
the case or 90 20 near the machine even
% shift the weights. Three long brass
rods extend from the base OF the case
containing the scales. and az the extrem-
| ity % each D. wheel, and boy turning
these wheels the weights may be shifted
| from one pan 20 another. or any other me-
cessary operations conducted. The read
| ings are made through a small telescope
mounted where the operator stands
Too late tt was discovered that the es-
Enlistment o. the instrument Ia corner
Of the room was a mistake. The fact that
che wall Is three feet away and the oppo-
site one nine feet. has a marked effect on
| the scales on the side where the wall "a
close the temprature g. different from the
other side. and whenever the instrument
IS used Il has been found necessary 70 sur
round it with large sheets OF asbestos
paper. Besides this the attraction OF the
wall for the metal in the scale beams has
% be- taken into account
These ore only a fcw OF the things which
have 20 be allowed for in doing fine JOB
Of Weighing. Large corrections have 20
be made for the temperature. humidity
and density OF the air Win each weigh
ing there must be a reading % the Their
mometer. barometer and hydromoter and
corrections 10 correspond 20 the conditions
existing at the time. In Germany there
ore scales SO built that the weighing can
be conducted in vacuum. but this gov
eminent owns no such apparatus.
Incredible as % may seem Inc difference
OF an inch or two from the center Of the
earth. thousands 81 miles away. causes
an appreciable variation ia the weight q
| the objects. This Is illustrated by plac-
lag two equal weights side by side in
each pan. when the beam shows no varia-
| ton. But place one OF the weights on
top Of the other In one pan leaving the
other pair side BY side IN the other PAN
and the balance will be disturbed The
weights used IN this experiment. are
scarcely two inches In hight 50 that the
| difference in distance from the earih's
center. considered IN comparison 70 the
distance itself. IS inhnfteslmal.
still further allowance d demanded by
! scientific accuracy Even IN a fifteen
| huudred-doilar Ruphrecht instrument
like the one owned by the government
bureau. 1t is not pretended that the two
arms Of the balance are Of the same
length. Ohicial Veriher Frank A Wola
SAYS that no scales were ever buHt IN
watch the arms were Of exactly the same
length. Tine only thing 10 do therefore
| Be- 20 check up the error by weighing al
/ iernaicly on one side ana the other. aud
then averaging the results
The standard from which measures OF
| length and mass are derived are stored IN
the same building near the Capitol. The
standard Of mass IS q cylindrical-shapei
piece OF whitish metal about the size OF
a tennis ball. The standard Of length is
2 bar of the slme siver-like metal about
| three feet long and "A little less than an
| inch square. Each face g. deeply groovei
and In one OF the grooves al either end Is
I a polished SPOT on which three delicate
IA FTFa.
these lines determines the end OF the bar
| The bar Is standard metre. and the
| cylindrical weight IL the Standard K 10
| gramme The material from which they
| are made Is a mixture % platinum and
| iridium. the latter being added 20 give ad-
ditional hardness TO the metal which
above all others Is recognized as the most
| durable. The value OF the metal alone in
| this standard meter Is 81 500 hut Il has a
much greater value from the labor ex-
pended la making IL perfectly accurate.
| The klogramme and metre standa rla
| are the result OF fifteen years labor by q
! joint congress Of scientists. supported by
seventeen OF the leading civilized nations.
| The international Metric Convention was
organized IN 1875. and on June 2 1897. the
| President Of the United States broke the
seal OF the standard kilogrnmme and
metre which fell 60 the share OF this couu-
try and tn the presence Of the secretary
/ Of the treasury and a number n invited
] guests assembled in the cabinet room OF
! che executive mansion. dcc.ar,d them
officially adopted.
| These originals have been used but once
| since. This was when a very accurate
| copy was made from each Tor practical
/ use by the government bureau In regulat-
| lng the standard weights and measures
! Of the country. The original klogramme
! was then placed under two glass bell jars
| which were locked nnd sealed. No human
! hand mas touched the kilogrnmme since
! u left the makers IN Paris; what little
/ handling has been necessary has been
/ done with pair Of special torceps Gov
cred with soft chamoic skin. THE Is 10
! prevent increase 81 weight by the adj
/ heslon 81 minute quantities Of foreign sub
! stances. or decrease OF weight by an abra-
/ sion
II has not been found necessary to ex-
/ crcise an equal degree Of care In prescrv-
| Inc the standard meter; little moisture
/ or dirt would not lengihen or shorten the
| metallic bar. Nevertheless " ~ kept IN
| a case 81 velvet surrounded with wood
/ and protected on the outside BY a heavy