Fort Worth gazette. [volume] (Fort Worth, Tex.) 1891-1898, 1893-02-01
AeouT THERMOMETERS.
Everybody Wants One Nowadays and Here's
How They Arc Made.

Thermometers have entered into the
household economy I'm a way that Is sur
prising. Thermometers are n good thing
10 have around. for else how can yuu
tell whether it is hot or cold? 1t Is a
silver dollar to q doughuut that half the
population take their temperature from
them, just as they do. at times. take
their b1rometric information from air.
Dunn and the newspapers.
Tile making of u thermometer mag ho
either "a delicate scientific operation, ar
one OF the simplest tasks Of the skilled
mechanic, according 10 the sort Of thcr.
mometer you want With the extremely
sensitive and infinitely accurate instru-
ncuts designed for scientific uses great
care is taken, and they are kept in stock
for months. sometimes for years, 60 be-
compared and recompurtd With iustru-
meuts that are known 90 bee trustwor-
thy.
But 80 much time cannot be- spent
over the comparatively cheap thermOmu-
tiers in cumiuOr use. These are nude
/ rapidly, though always carefully The
method of manufacture has been $50 syS-
tpmatizod within recent years that the
very cheapest thermometer should not
vary more than the fraction Of q degree
fruu the correct point.
Whether the thermometer Is 10 De
/ charged with mercury or alcohol. wheth-
/ or it ia To be- mounted iu a frame Of
D
/ vs. substantially the same. Mercury is
! generally used for scientific Instruments.
/ hut most makers prefer alcohol because
/ q Is cheaper The alcohol H. rolOrpd red
/ with an uniliue dye which does not fade.
The thermometer maker buys his glu~s
/ tubes IN long strips from the glass iar-
/ tories The glasshluWcr cuts these tubes
/ tu the proper lengths. aud with his gus
| jet aud hluwpipp makes the bulb ON the
| lower end. The bulbs are then filled
! with culorcd alcohol and the tubes stand
I for twcnty.four hours. On the following
| day another workman holds each bulb
[ In tpru over the gas ipt until the color
ed iluid 10y its expansion Ills the tuhc.
IL Is then tnbcn hack to the glasshluwer.
/ lie closes thc upper eud aud turns the
top backward to make tho little gus'
hook which viii help 10 keep the tube
in its place IN the frame.
The tubes now rest until great mum.
her Of them ara reudy Then thc pro-
| cy-S of Eauging begins, There are ma
| marks whatever ON the tuhr. and The
first guide mark TO be- made is the frcea
Ing mark,
This is formed by vlunpiug the bulb.
1 into melting snow. No other thprWoW
otter rs needed for q guide. for melting
snow gives invariably the exact freezing
poiut. This is am unfuiling test for ANY
Thermometer whose accuracy may be
doubted. Melting snow rs not always
tO he had. md little machine resem
bling % suusOrnw'ndrr rs brought int,
usc This machine shuvrs block Of To-,
into PARTICLES. which answers the purpose
~ well ~ snow.
When the bulbs have been long enough
Iva the melting SHOW, q workman tNkw
them one 10y one from their ley bath
Selling each one so that his thumb mai
marks the eNRct spot to which the 0ui'
has fnlru. Hero he makes a scarcely
pprconNhip mark upon the glass with
fine file aud goes on tO the next.
; The tubos with the freezing nOin
marked on each now 20 INTO the hand
, uf nuWhur workman who ulunges them
bulh down into vessel hlled with waite
lcpt CONSTANTLY M 90 degrees. \ stor
p dnrd THERMOMETERS attached tu tho ius.d
. Of this vessel shows that thc trmp"l
p nUre of the water Rs correct Auoihc
tiny file scratch IL made ~ o..
th.rl timr the bulh Is plunged int
e water kent constantly nc 90 which, lik
I the others. "a marked A tub Us nNye
IN each tnhc II is given over tO IN
marker, who fits the bulb and hook I'M
franc, and makes slirht SCRATCHED
p corresponding 10 the %, 90 and 8
< marks Il rs next given over 10 wor'
e. man who cuts the degree marks.
=, Altogether, " tnlos nWptoen w1rl
!. people Ia make u Thermometer. Mn
are femnlpf ANY time Won huvc tin
Won could not spcud half day MOI
|, plpnsputy than looking az the maxim
| Of thermometer.