Alma record. (Alma, Mich.) 1878-1928, 1888-03-09
THE
It's Value I'm scientific Researches,
and the Erroneous Ideas Regarding

~ hfHhfHl ItitltuCts u inc thermometer
nj the time OF a "cold wave" and every sud
den rise and fall In the temperature, may be
regarded as s~iTording ev idence of the uniyers
al confidence manifested In its iudlcatlons;
and when properly constructed, with an ac-
curate graduated scale, it can be almost In
var bly, dep ndcd upon as a reliable indicator
Of The temperature, says a correspondent Of
TIE ietro { FIRE. Press. But when cheap and
imperfect instruments, made by persons who
know but very little, If anything, as to their
proper construction, are palmed of on the
public by neiar.ous vendors claiming 10 be
dealers IN scientific apparatus it Is not to
be wondered at, nor should it Ice very surpris-
ing that our thermometers vary greatly In
their indications, even when hung in
the same locality. AMI that we hear Of so MANY
conflicting reports about the temperature and
the number Of degrees below zero" TO which
various persons claim the mercury has fallen
during every cold snap" that prevails In any
portion Of the country. How frequently do
We hear Of thermometers, hung not far from
each other, that vary In their indications all
the way from one to eight or ten degrees
owing partly, no doubt. to some having been
more exposed to the wind than others, and
not being suspended as they should be, but
chiefly 10 imperfections In the instruments
themselves.
The thermometer, regarded as q scientific
Instrument, may be rightly called one OF the
most valuable and wonderful inventions OF
the world, and is entitled 10 be ranked in i'm
p~ortance with the barometer, with which il is
commonly employed as an almost indispensa-
Bile companion in nearly all meteorological
and other scientific Investigations. Among
all the invention OF scientific ingenui-
ty, the thermometer, together with the
barometer, has not only become Of
general use IN the practical avoca-
lions Of life, but has proved a valuable attend
ant TO man through all the various climes aud
countries OF the world. To It alone we owe
the knowledge We have acquired regarding
the differences OF climate In various regions
aud nights Of the earth's surface, the infof-
nation we possess relating 10 the variations In
the average temperature OF seasons and DAYS;
aud, moreover, what NE are able still to sav
respecting heat aud its effects, would greatly
lack precision Il the means-which we find in
the hermometer-were not at hand and avail
able TO measure It's power.
The ordinary purposes for which the Their
mOmeter is used, are known TO all and its en-
plOyment rs a means OF determining the tenn
pcrature OF the sea at great depths: its i'm.
portance 10 the analytical chemist, and % the
aerial navigator In studying the upper regions
OF the atmosphere; its value In asccrtaining
the nights OF mountains or balloons by the
falling II the mercury; and its more recent
application in medical science, aud employ
ment by physicians in obtaining the tempera.
ture OF the human body ia sickness, are
among the numerous examples OF its useful
ness, familiar 10 almost every person who is
acquainted with the teachings of natural phil
osophy aul metcorology.
The thermometer, iu its crude form. was in
vented By Il Hollauder named Cornelius Dreb-
bel, Who 1t appears made The first instrument,
which he called a ''ncat mrasurcrV i'm tho
year 1858. His thermometer was simple
enough, aud had numerous defects. consisting
Of a glass ball al The top II "A long tube. the
lower and open end being placed In a vessel
filled with water, cOlored by a solution OF nj.
trate of copper. This instrument was i'm
proved upon, and it, defects gradually re-
moved by Others, but IL was HALEY, the
famous English astronomer, who first proposed
the use Oh mercury as a huti for The Their.
mOmeter.
There are now three kinds Of thermometers
In common use throughout the world; but the
form invented by Prot. DAME Fahrenheit, an
ingenius German in the year 100, and from
whom the instrument has been named. is tile
one generally employed in this country, and
with which nearly every intelligent family in
the land is provided, though the ''centigrade
thermometer' is really the most convenient
aud Is now adopted In all countries as the
standard scale Tor scientific reference; and
like the metric sys' EN-, its general use in this
country is doubtless merely a question Of
time.
Mercury hoils ana yaporizos az a tempera-
ture Of CO.. Fab, and for obtaining any high
cr temperature than this a metallic instru.
ment ca lei the promoter j. made use OF,
but is indications are unreliable, aud II yet
remains 10 discover some more accurate
method 4 measuring degrees OF heat higher
than 90 by the Fahrenheit thermometer.
Al n tenn erature OF 30 below zero mercury
freezes and becomes n solid mass malleable
under tn hammer, aud for lower tempera-
lures, pare alcohol (%spirits 81 wine) colored
red with caruine, i usually employed, but as
IN The case OF the its Indications
cannot be depended upon for accuracy.
Fahrenheit was not slow 10 recognize the al
v~antages possessed by mercury as a fluid for
the tube Of the thermometer. Mercury. as an
excellent Conductor Of heat, il vastly more
susceptible 10 the changes Of temperature
than All other fluids. II Is much more easily
obtained iu a perfectly pure state than
alcohol, which, even when prepared with the
greatest care, often c%antains air as we'll as
other almiItures, and alcohol IL sometimes
rendered thick by great degrees OF cold. and
under the higher degrees OF heat IL expands
excess vely snd ununlformlv.
In the Fahrenheit thermometers the space
between tlr freezing ana bOlllUg point OF
water IL divided INTO $50 equal parts or he.
grres, the former being 32 and the latter
2l2o above zero, VIII ch was sOcalled by the
inventor from the fact that he supposed II 20
indicate the point II absolute cold, or the
very lowest degree that could be produced
and measured br anv instrument. But the
lowest degree OF cold possible 90 he obtained
IS now estimated 10 Doe 523 : and the greatest
artifc al cold ever produced is 93 by the
Fahrenheit thermometer. The zero point OF
a thermometer does not indicate the total
absence OF heat, rs commonly supposed, ana
the term seems tO imply. for an absolute zero
OF temperature has never vet been attained.
and has only been approximately determined,
though it is considered convenient - AN
ideal ~starting-point" The zero OF y FAhrcn-
heit thermometer is the temperature Of mix
ture Of ice and common salt, which is usually
employed In the operation OF freezing Ice
cream.
The zero point ~ a thermometer should al.
ways be carefully verified, unless ;he iustru-
ment Is known TO be correct. To do this
immersc the bulb In vessel filed with snow
or pounded Ice. and press lightly a layer 81
/ several inches around II, So that the stem.
which should he rractly nerpendicular is cov. /