The Rutland daily globe. [volume] (Rutland, Vt.) 1873-1877, 1873-09-09
ments with mercury convinced him that his
conclusions were correct.
'Eubanks Hydraulics, page 1856

show that his conclusion in regard to other
liquids was not a correct one, by submit
ting the following for consideration:
Vacuums If the same degree of pcrfec-
ton can not be formed over the surface of
water and volatile liquids, as can be formed
over mercury.
Different liquids boil at different tenn
peraturcs, ranging from 90 the boiling
point Of ether, up to G62 : the boiling /
point of mercury
No vacuum can be formed over u liquid |
whose temperature is at the boiling point. |
The boiling points of liquids have no re-
lation to their specific gravlties, as will APP
pear from the following:
Mercury bolls Mt C62-, with specific gravity |
OF 1880
Sulphurc acid bolls at G209, with a specific !
gravity OF l,s4i.
Water bolls at 2l2o, with o specific gravity OF
/.
Alcohol bolls at l,9o, with specific gravity
of I92
sulphurlc ether Doils at 9co, with specific
gravity Of res
1t is evident that if Torricell had made
his experiments with his apparatus, water
and mercury, at temperature Of pig :, no
water would have assembled his pipe, as its
cohesion would have been destroyed, while
it would have required the addition of
4503 to destroy the cohesion that still re-
manned in his mercury.
The apparatus which | have used for
measuring the cohesive strength of liquids
consists of glass tube 80 inches long. with
one end closed, with an inside diameter of
one inch. Also smaller glass tube of the
same length, with an outside diameter of
about inch. The diamcterf of these tubes
should be such as to allow the smaller one
to pass freely into the larger one. On the
outside of the small tube, | laid out n
3O-nch scale, commencing mt o three inches
from the top end, and numbering down
wards to 30 inches Also n scale Of three
inches laid out from o to the top end of the
tube. On some of the small tubes these
scales were made on the glass itself, and on
others they were made on narrow strip of
white paper pasted on the glass. On the
upper ends of these tubes, brass plates or
caps were tightly fixed, through which II
small tapering hole was made, that could
be closed with brass plug ground toa fit.
After the large tube has been supported
in Il vertical position, sufficient quantity
Of mercury is put into it, to allow the
small tubes to be immersed TO O, the start
ing point of the two scales. The air in the
small tube being permitted to pass out
through the lapering hole in the cap. allow
ing the mercury to stand at the same level
in both tubes, leaving the inch scale
above the mercury. The upper part of the
small tube is then filed, Through the hole
in the cap-plate) with the liquid to be
tested. The hole in the cap-platc is then
closed with the plug. BY raising the small
tube out of the mercury, it will remain
filled, until the weight of the mercury
column thus raised, equals the cohesion of
the liquid. at which point it will be seen to
break The length of the mercury column
sustained by the operation, can be readily
noted on on the 80 inch scale. To the weight
the weight of inches of the liquid that is
In the test tube, this will give the cohesive
strength per square inch of the liquid, at
the temperature it had when the test was
made.
During the progress of an experiment
just before the rupture of the liquid occurs,
an innumcrable number of minute air bub-
bles can be seen scattered through the en-
tire body of the liquid. The removal of
the atmospheric pressure allows the air
contained in the fluid to expand sufficiently
to cause perceptible frightening of the
column AS soon as the rupture occurs,
the space produced by the separation is i'm
mediately filled with vapor, and at the
same time the air bubbles begin to ascend
in fine thread like streams, into the same
space.
After pressing the small tube down into
the mercury nearly to O, the plug is re-
moved, when, by further pressing the tube
into the mercury, sufficiently to cause the
liquid TO just fill the hole in the cap. the
vapor and air arising from the first operation
will be removed. BY replacing the plug,
and again raising the tube, n less amount
of air and vapor will be seen to enter the
vacuum space, and longer column of mer-
curry will be sustained in the tube These
effects were observable for three or four
repetitions, after which the length of the
mercury column would not increase
have found this to be the case with all of
the liquids with which have experiment
ed.
Tha following table shows the results
which have obtained from experiments
made with water, sulphuric acid, alcohol
and sulphuric ether. The experiments
were repeated four times with each LIQUID.
except the ether, which was repeated five
times.
The first column gives the inches of mer.
curry supported in the test tube at the time
the rupture occurred in the liquids.
The second, gives the cohesive strength
of the liquids, in pounds per square inch.
The third, gives the temperature of the
liquids when the tests were made.
The fourth, gives the length of columns
whose weight is equal to the weight sus-
tanned in the test tube at the time the rup-
ture occurred
The fifth, gives the state of the baromc-
ter
And the sixth, gives the length, or
height in feet, that the liquid columns
should have to accord with the views of
Torrcelli.
The experiments were made at an clcya-
ton of $50 feet above tide water.