Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1883-08-22
The Thermometer,

The history of the thermometer is
more yoluminOus than that of the tele-
scope. The actual inventor of the in
sIrUmeDt, like many belefacto-s OF the
world. Is unknown to fame. The first
attempt al indicating 10 the eye differ
elces of temperature is Variously as
cTibed 10 DTebbel, of Holland, and
>anctOriOus, Of Italy. In the first ther-
mometers, which date back 10 the be-
ginning OF the seventeenth century,
the glass tube which held the fluid was
open al the upper end. But the Flor
eutiEe acddemicians suggested the clos
ing Of the tubes, which would prevent
evaporation. When the Instrument was
brought 10 England, Boyle proposed to
substitute cOlOred for the coloTless fluid
used IN the closed spirit thermometer.
HOOke, III 1861, suggested another i'm
pTOyeInent in them, viz: Marking as
one OF the fixed points on the tube the
point al which, when it was plunged in
freezing wafer, the liquid came To rest
Haley. IN 1888, suggested the tempera-
ture Of boiling water as the other fixed
point on the tube. But Newton, who
nnst demonstrated that pure water al
MAYS bOils, under a given pressure, at
a liked temperature, seems TO have been
the nrst 10 take advantage of this
physical law in improving the ther-
mOmeieT. Ii Is said, however, that
Calico was the real inventor.
But the great Improvements of the
thermometer, which in its simple form
still adheres 20 the principle of the old
Florentine pattern, have been the sub
stItutiOn Of mercury for spirit and the
graduating Of the tube with reference
tO the freezing and boiling points of
water. The advantages of mercury as
a therm0metric liquid are the great dis
taIsce between its freezing point and its
boiling point, the uniform rate of its
expansion over this range, and its high
clnductiyIty and sensitiyeness to heat
eiianges.
The more modern scales for gradua-
ling thermometers are those of Fahren-
heIt, Reaumur and Celsius. In the
cenugTade Thermometer, Celsius's in
genii0n-nuw almost everywhere used
lu EuTOpe-the distance between the
freezing and boiling points of water is di-
yided into 100 equal parts or degrees, the
freezing point being marked U degrees,
and the bOiling point 100, While in
Fahrenheit the same distance Is divi-
ded into lo0 degrees, the freezing point
of water being marked on the scale as
3. and the boiling point 2l2. Reau-
mur's scale divides this distance into
eighty equal parts, but Reaumur ther-
mOmeters-Once preferred in Russia
and GeTmany-are, for good reasons,
going INTO disuse. Although the cent?
grade Is most used abroad, it will
probably never supersede Fahrenheit's 5
.u English-sPeaking countries.
since Fahrenheit IN Holland pro-
posed the substitution of mercury for
spirits OF wine as thernOmetric fiuid
In 1914 and his scale ia l724, and Celsius
ii sweden proposed the centigrade
scale about l142. the Improvements of
tie instrument have consisted chiefly
IN periectng the method of its CON
stTuciion - determining its fixed
points freezing and boiling }, gradu-
atIug 81 the scale, and the calibra-
tiou' and Correction of the therInome-
ters 50 as 20 secure maximum accuracy.
The instrument as now made consists
81 a capillary glass tube. at the end of
which tie buib Is blown, usually in |
spherical but far better in cylindrical |
ioun. care being taken that the tube is |
SD nLe lu proportion TO the bulb as TO |
admit vi a scale sufficiently extended |
o. show any extremes of heat TO which |
The Thermometer Is 10 he exposed. \ |
small funnel Is blown at the top of the !
tui- and filled with mercury, when, the /
tie tuie being slightly inclined, the /
aiT BOZ tLe bulb j. expanded by heating |
ltL % spirit lamp. The expanded air /
PARTIALLY ESCAPES by the funnel, the air |
Hhlrh remains contracts on cooling, |
alluRllE portion of the mercury To |
f4l inio ibe bulb. This process is re- |
Is1f~l until the bulb and part of the |
tub are llied with mercury. when the |
meDuy is boilt1i, the mercurial yapors
driving aii AIR and moisture entirely out |
81 the iuie, which Is then Theoretically |
--siird and laid aside 10 cool. The ther- |
il0Birier now being filled, it is next |
graduated To do this the bulb and |
lart uf The tube are immersed for fifteen /
minutes u pure water. with ice OF melt |
ing snow added. and mark made at |
the i-gel to which the mercurial column |
-luk,, te represent the freezing point /
- degree, in Fahrenheit ;, or zero in l
tlr cent grade To determine the other /
laci point the thermometer il lowered |
Hlio a vessel containing boiled distilled |
waiter. tie bulb not quite dipping into /
tie liquid. but the whole thermometer
surrounded by the steam. This must /
IT, done when the atmospheric pressure
], ~ Z9.90 inches, or allowance must be |
made I u j. greater. The point at
which tie mercury stands IN the vessel /
~ boiling water is marked on the ther-
mom-ieT tube as 2l2 degrees Fahren-
heif, OF 100 for centigrade, and the
intervals beeween tins and the freezing
point j. equally divided. In the most
accurate thermometers the scale is
marked On tie glass itself, the stem
being coated With wax, and the diyis-
ions and corresponding figures marked
AIth a steel point. When being exposed |
10 TIE yapOr' Of hydTO1u0ric acid /
Hhich attacks the glass where there is
n0 WaN !. the stem IS distinctly etched.
To insure the best approach To accu-
aey other precautions and tests are
employed. such as cahbration," al
n'ldy mentioned, which consists in ex-
auiIing the bore Of the tube for ine-
qualities IN IFS diameter and making
allowance and correction. Amateurs |
would DO well 10 have their instruments
compared with some accessible stand |
ARD such as those used in the stations |
81 The signal service.
DeJecfs "a House Drains The CON-
non d,fects IL house drains may be |
fIuz arrsrnarafaf. ~ Tho ioiptS ~, Il