Orleans County monitor. [volume] (Barton, Vt.) 1872-1953, 1884-11-03
SOMETHING ABOUT THEIR
MOMETERS.

+
the glass-blower first blows bulb on
the end of long tube. While this
tube is hot the end of the tube is in
serted in mercury, and as the bulb
cools the mercury rises and fills the
bulb. This process is repeated until
the bulb and part of the tube are fill
ed. The bulb is then immersed in
snow or Clipped ice and the mercury
settles to the freezing point, which is
marked on the scale as 32o if Far
enheit scale is to be followed. Next
the bulb is put in boiling water,
and the point to which the mercury
rises is marked on the scale as 212o.
Ten degrees of the mercury is now
detached from the column by jarring
and the whole length of the tube is
tested. The process is repeated with
five degrees of the column being
measured all the time by standard
thermometer to see if the tube is con-
ical at any point.
They generally vary about two or
three degrees, owing to the irregu-
larity of the opening Of the tube,
which causes the mercury to rise
slow where the opening is
too large, and too fast where the
opening is too narrow. 1t requires
great skill to blow a tube with uni
form opening the whole length.
They should be allowed to stand
not less than one month-one year is
better-to allow the mercury to set
tie before the scale is made.
The self-registering thermometer is
used for marking the highest and
lowest points reached within given
: time. The bulb is filled with mercu-
ry, above which, in the tube, is in
serted fine piece of steel spring
the remainder of the tube is filled
+; with carbolic acid or creosote. The
+. steel spring rests at the highest point
: it is pushed to by the mercury and is
S afterward drawn down by small
I magnet. By duplex arrangement
: and reversing the scale the lowest o.
n coolest point is indicated in the same
/ way. The deep-sea thermometer il
II of the same pattern, and incased in
heavy copper tube to preserve
Il against the pressure of the water. /
$ has, besides, self-regulating attach
s. ment. The fever or clinical ther
II mometers are made with great nicely
: and are used for determining th
N temperature of the human body.
L Mercury is commonly used for fill
III ing the bulbs, it being highly sens
70 tive to heat and cold, but in the ez
I'll treme northern climates it will ne
~ answer, as it freezes forty degree
We below zero. When this temperatul
u is liable to be met spirit thermom'
50 ters are used, being made of alcoh'
TO colored red or blue. These spir
III thermometers will not answer fl
ay high temperatures, however, as Il
alcohol votalizes too readily.
us There is new style of plain the
eh mometer made with an elongatt
et- bulb with the tube balanced near Il
II, center on pivot. As the mercu
ell rises above the pivot, the point
10 the tube is depressed, and mov
'ur along an index like the hand of
eel clock. The thermometer can be re;
Or, with ease across large hall. The
IS are also many new contrivances f
le; registering degrees of heat and CO
)n- attachments to indicate at what ho
er' the temperature indicated was reac
cry ed. Thermometers are also ma
IN with wire attachments, so that t
mercury rising to a certain point W
ely touch the wire and complete the C
Ike cuit of a galvanic battery and sou
an alarm. These are useful in t
MS drying rooms of paper manufact
ries, greenhouses, and as provisi
ly, against accidental fire.-N. 7. III
ca, une