New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-12-25
GRADUATING THERMOMETERS

now TIE MERCURY IS GOT INTO THE TUBE-EA
TENT OF THE DEFscTs IN INSTRUMENTS.
A TRIBUNE reporter, with curiosity 10
learn how Il mercury gets into the tubes OF thermome-
terra and how the instruments are graduated recently
vislted store wlamst, and was there instructed
when a Thermometer is 10 be made said the manuiao-
urer the glass first blows bulb on the END OF
long tube While this bulb Is hot the end OF the tune
inserted In mercury aud the bulb eools the mercury
ses and oils the bulb This process is repeated until
the bulb and part Of the tube filed The oub Is thep
immersed IN snow or Clipped and the mercury settles
20 the freezing point which Is marked on the 'oe as
u n Fahrenheit scale DO followed Next the ouio is
out in boiling and ths point to which tine ero,
rises 10 marked the scale a. 2l2 len degrees vi
tne mercury are now detached from the column oy jar
,pc and tho whole length Of the tube Ia tested TP
process. ia repeated with five degrees Of the column be
ing measured ell the time by standard Thermometer 10
acc II the tube IA concal at any point"
"Are common Thermometers usually correctP
They generally vary about two or three degrees ow
ing 20 the rreguarty OF the opening In the tube whlch
auses the mercury 70 slowly whero the opening
TOO large and TOO fast where the opening ia too narrow
Il requires great skill to blow tube with UNIFORM
opening the whole length.
Are Thermometers ready for Immediately after
| they are filed with mercuryr
aThey should be allowed to stand not less than one
month-one year is better-to allow the mercury W
| settle before the scale is made"
awhat are the different kinds of thermometers that
| are nader
~Jhe selfresterng Thermometer Is used for marking
.he highest end lowest points reached WITHIN sglVen
limo The bib is nled with mercury above which, In
tho tuhs IA inserted fine piece OF steel spring the
OF the tube IA filled with carbolc acid or ereo
.ote The steel spring rosts ct the highest point Is
pushed to by mercury and Ia atterward drawn down
| nv small magnet. BY duplex arrangement ana re-
yersing the the lowest coolest point is indicated
in the same way. The deepsea thermometers OF tue
.ame pattern incased in heavy copper tube 70
against pressure Of water II has, BESIDES
a self-regulatng attachment. The fever or clinical
thermometers made with great nicety ana are usou
for determining the temperature OF the human body.
aWhat IA used for filing the bulbs OF Their nometersP
MERCURY is commonly used, 1t being highly sensitive
m heat ana cold Lut for the extreme northern climates
il will not It freezes at 400 below zero Mnee
are used being made OF alcohol cOlored RED or nlue'
These spirit thermometers VIII not ansNer ior 1n
peraures, however as the alcohol Voiatzes Io' roau
Is there Government standard for testing thermOm-
ia no Government standard The signal Ser
vatory OF Yale College has established IhermonetrlC
bureau testing Thermometers either Tor dealers o.
others interested In procuring exact lnstruIlehls
small fee ranging nom hity cents to ~ u on r
Yale certificate of correctness u
and It's services OF great value 20 III ss
Ing clinical Thermometers me o0,eTvs'@ S ns oeSn
statements The composition OF business ooupds S
rystopv in this country paying special attention e
1har,nonIetrv 10 which authoritative appeal could "
nie laA 40 Affected manufacture OF thermometer
for medical purposes that seems necessary 70 Issue
o | card briefly indicating tue errors commonly Ibuh'
oexist and to Why In this tho representa-
ons OF the dealers may be at fault through tho wan9
nroper understanding of the subtle errors 10 whio
medical thermometers liable. Too great desire
. sconomze time good material and skilled lnhor mas eu
in the making OF thermometers the following faults
g. ia Tie graduation sometimes started from ono pom
Of the soas the normal and the size OF inc cap
larry tube guessed at upper pointbeing nxed oy IN
maker the higher graduatons may be erroneous 20 IN
sytent Of aeveral (2l Too much sir senfatn
rms index FROM the column OF mercury oanses the nue
10 rise with motion; air above the lndex Iofce
me index down when the thermometer IL taken ava
cause amount TO degrees at Agh temperatures 70
New thermometers increase their readings rapdlyuurln
the first nOnths after manufacture 80 that lnstf
which right when made may cnnnRe tnelr ihuioa
No lions IA much rs two degrees within year. " -.
nS Are there any late improvements In tnermometersF
40 "In the old style OF clinical thermometer there was
.,oalI space OF oxygenized air separating the column
meroury that held the upper portion Of mercury at tn
maximum points contraction Ia made IN tne tuu
that the mercury nc the maximum point unvl
Ia Jared back to ia place. TheroAs also new sly
no OF nan thermometer made with elongated ouio WI
be the tube balanced the centre on pivot As tu
mercury rises above the pivot tho point OF the tuoc
:" depressed and along an index Ike the manu-
clock This thsrmometer be road with ease &C ros
10 large hall There also many new oontrfvsnees
registering degees Of heat aud cold with oiock sttael
mcnts 10 indicate the hour the temperature naloate
was reached Thermometers are also made Win WI
attachinens that the mercury rsin TO acertMn po
will touch the wire ana complete the circuit OF "a
yanc battery and sound alarm. These are usefui
~ the driving of paper manufactured IN grooi
ed houses and a. provision against accidental nre