Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1892-07-15
WEATHER GAUGERS.
THERMOMETERS ARE MANuFAc>
TuREo WITH GREAT GAZE

THERMOMETERS ARE MANuFAc>
TuREo WITH GREAT GAZE j.
shey Are Asds Very Aeeurnteiy, sad,
1heash Qu:skly, PAS Throagh nins-
ses6 PaIrs Of Hands--Ths DfRsrsns
Praesssss Of the instrumspts.
The making Of Thermometer may be
either delicate scientific operation. on
one OF the simplest tasks Of the skilled
mechanic. according to the sort Of Their
mometer made With the extremely
sensitive and infinitely accurate instru-
ments designed for scientific uses great
care = taken. and they are kept in stock 4
Tor months. sometimes for years, to b. |,
compared and rscolnpared with instru- !
ments that are known to be Trustworthy.
but 10 much time cannot be spent over
the comparatively cheap Thermometers
In common use, and these are made rap
idly, though always carefully. The
method Of manufacture has been 70 sys-
tsmatized within few years that the
very cheapest thermometer should mot
vary more than q fraction Of . degree
from the correct point
Whether the Thermometer IL to be
charged with mercury or alcohol: wheth-
er 1t is to be mounted in . frame of
wood, pressed tin or brass, the process
u substantially the same. Mercury IL
generally used for scientific instruments,
but most makers prefer alcohol, because
it II cheaper. The alcohol 10 coIored
red with an aniline dye which does not
fade.
The thermometer maker buys his glass
tubes In long strips from the glass fac
tories. The glassblower ON the premises
cuts these tubes to the proper lengths,
and with his gas jet and blowpipe makes
the bulb on the lower end The bulbs
are then filed with colored alcohol, and
the tubes stand for twenty-four hours
On the following day another work
!, man holds each bulb in turn over q gas
jet until the colored fluid. by its expan
!, sion, entirely fills the tube 1t ther
goes back into the hands Of the glass
! blower. He closes the upper end and
turns the tip backward to make the bit
3 tie glass hook which will help keep tn
:, tube IN place IN the frame
MARKING THE TUBES.
o The tubes now rest until some hun
% dreds Of them, perhaps thousands, ar
;; ready Then the process of gauging b
gins There are no marks whatever o
" the tube. and the first guide mark TO b
s. made is .ths freezing point, 80 deg
20 Fahrenheit. This is found by plungin
ae the bulbs into melting snow. No othe
Mt Thermometer is needed for guide. fc
ne melting snow gives invariably tho exat
81 freezing point This is an -nfailing te<
for any Thermometer whose accurac
Ill may be suspected But melting snow
OF not always to be had. and a little m
i chine resembling a sausage grinder
a. brought into use. This machine shaw
We a block of ice into particles. which q
az swer the purpose as we'll as snow
IN When the bulbs have been long enout
OF in the melting snow workman tax
ne them one by one from their icy bat
I'M seizing each so that his thumb n;
EN- marks the exact spot to which the flu
iot has fallen here he makes scarce
'uf perceptible mark upon the glass with
Up, fine file. and goes on to the next
zen The tubes. with the freezing poi
rth nartad nm each now 90 into the han
len of another workman. who plunges the
nc bulb down, into a vessel filled wi
md water KENT constantly at "a de;
an A standard thermometer attached
go the inside of this vessel shows that
of temperature of the water IS CORE
mp. Another tiny file scratch IS put at 81.
ems Then a third workman plunges
bulbs into another vessel of water X
nts constantly at g. This Is mari
and like the others, and the tube is now S
ave nlied with these guide marks. e;
ity, 81 dogs from the next A small
in is then attached to each tube, on VIII
ton its number is written-for. owing to
ayoidable variations in the bore of
tube. each one varies slightly from
q others.
u MARKING THE CASES
pro With its individuality thus establis
.tt.' the tube goes into the hands OF M
YAK er. who fits its bulb and hook into
ols frame it is to occupy. and makes sli
si.o scratches on the frame correspondent
p III the 30, GA and 90 degree marks on
sac tube. The frame has a number CO
itsn sponding with the number of the t.
IN and the tube is laid away in rack a
r.: thousands
irdi- The frame, whether it be wood,
add or brass, goes to the gauging re
ir'y' where it is laid upon steeply slol
~ 10 table. exactly in the position markes
W I'D ,ha-,nop,atEar of that size. The 8