The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1897-11-21

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as shown in figure /. This joint must
| be absolutely air-tight, and for this
purpose it would be better to soak the
cork in boiling paraffin wax, and to
have it thoroughly smeared with soft
hot wax before making the joint. This
| is the most careful part of the making
of the instrument, and upon it success
depends. The apparatus. is then set up
as is shown in the figure, being suit
ably supported to the wall by blocks
of wood and thin clamps, and the low
er end of the tube is dipped in some
colored solution contained in the lower
bottle. Water, colored deeply with or
binary blueing, or analine ink, will an
swer very well. A piece of pasteboard
should be fastened behind the tube
! conveniently for marking a scale.
The range of this thermometer will
be found to be confined to a limited
number of degrees, but the space trav-
! eled by the liquid for a, single degree
! is remarkably long. The larger the
| bulb the more sensitive the thermom-
eter will be. The thin glass bottle is
the bulb of the thermometer and the
position of the liquid in the tube is the
index of its temperature. The lower the
! liquid the higher the temperature, ex-
actly the reverse of the mercurial Their
mometer. Therefore, if no further steps
are taken to adjust the height of the
| liquid in the tube it follows that the
absence of any liquid in the tube itself
| indicates that the temperature is the
same as at the time when the Their
mometer was put together. This would
probably be between so and 10 degrees,
according to circumstances, and may
be ascertained accurately enough for
the purpose by means of a. mercurial
! thermometer.
However, it is probable that the
maker of the instrument will desire
That it include a higher temperature,
and for this purpose he must proceed
as follows: Let us suppose that the
highest temperature that it is desired
that the thermometer shall indicate be
10 degrees Z.
Hang a mercurial thermometer be-
side the bulb of the instrument you
have made, which is called an air Their
mometer, and cover the bulbs of both
instruments with a pasteboard box
filled with soft cloths saturated with
hot water. 1t is important to the accu-
racy of the results that the bulbs of the
two instruments be as near together as
possible Bubbles will begin to issue
from the end of the tube of the air
thermometer, and when ITO degrees is
reached on the mercurial instrument
the box of cloths should be promptly
removed and the bubbling will cease,
and the liquid will begin to rise in the
tube Then the absence of liquid in
the tube indicates that it's bulb is at a
temperature of about ITO degrees.
By means of the box of cloths de-
te1Tnine a number of points on the in
strument, using water of different tenn
peratures Let the indications of both
instruments come to rest before mark
ing the scale of the air thermometer in
these subsequent tests. Having ascer-
tanned 10 or Is points, the intervals be-
tween them may be spaced off with
dividers into the appropriate number OF
degrees, and thus the scale will be
completed. The points determined by
. waiting for the mercury to come to rest
are much more accurate than the'first
. point Determining the first point ir
the method indicated was Of value be
, cause it adjusted the height Of the
| liquid to about the range it was desired
, to give the instrument. If the instru-
ment is ever heated any hotter than The
maximum temperature it was intended
: to measure some of the air will bub
: BILE out, and the accuracy of the scale
will be destroyed.
: 1t is sometimes desired to indicat,
the outdoor temperature; for this pur
3 pose it is merely necessary that Thu
e bulb of the thermometer be placed out
:, doors. This may be very convenient,
n accomplished as shown in figure 3 Tn
Y wall is penetrated by a long girnlet
and the glass tube is bent at right an
t giles and forced through the hole AM
i fitted into the bottle as previously de
t scribed The celebration of the Their
d nometer under this circumstance i
d performed in a similar way, the mer
i curial thermometer being hung besid
Y the bulb of the air thermometer in al
E cases.
To bend the glass tube for making
an outdoor thermometer hold it at tn
t point to be bent, over the flame of
d spirit lamp, being sure the tube is dry
:, Do not breathe into it before heating
: and once in the flame keep it continu
ously revolving between the fingers
l Presently the glass will be felt to b
1 Welding at the heated point, and a mo
L ment later it will get red-hot. ]
E should then be removed from the fam
and be slowly bent, the arms of tn
angle being bent outward from tn
operator If too hot on the inside O
}. the angle the tube will buckle; if to
hot on the outside it will f1atten. Prac
t tice is necessary to make a first-clas
8 bend and it Will be better for a movie
e to experiment with small bits of tub
r ing before bending large one.
The air thermometer as arranged i
+ Fig. 2 will enable the outdoor tempera
6 ture to be observed from the seal
+ which is inside a warm room.
: One Only of One Style.
n EpdIaSc wa riatv Of artistic r,roS1,o