Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1878-01-30
For the Vermont Waterman
"The Mechanics Of Cream raising"

vi
In your paper of December 18th, | notice
an article entitled "The mechanics of cream
raising" in which the writer seems to in
sinuate that all theories except his own are
"hobtailed science" and all patented ar
rangements for facilitating the separation
of cream are merely humbugs, gotten up to
"gull confding public" m As my views,
both on the subject Of patents and cream
raising, differ considerably from his, would
like to give the public chance to judge be-
tween us. | am convinced that he is utterly
at fault in regard to the very simple physi-
cal laws and facts connected with cream
raising" He seems TO have beau ideal
temperature ri by which to raise cream,
and believes if milk is reduced to a tempera-
ture of forty degrees, cream will separate it.
self of its own accord. If he had said one
hundred and forty degrees, it would have been
more consistent with his belief that cream
rises at stationary temperature; as milk is
much more porous at high temperatures than
low Ones and cream would make its up
ward journey more easily through porous
than through contracted milk. High tenn
peratures are also more desirable if we say
anything about the specific gravity of cream.
T31 Cream swells with heat and shrinks
with cold, more than the rest of the milk,
therefore it is evident that the fat in cream
being relatively lighter at high tempera-
ture than at low one it would rise pro-
portionately quicker. This gives the advo-
Gates of stationary temperature-whether
high or low-all the ground for which they
ask. Now know their theory to be utterly
fallacious and unsupported by single
scientific fact. | have been obliged to de-
pend mainly upon practical experiments,
and the results of these have shown me, be-
yond a doubt, that cream rises by rea-
son of currents in the milk, produced
by changing temperature. Al
The writer of the article in question says
"perhaps passing the milk through some
simple cooling apparatus might obviate the
necessity of cans small in diameter and in.
COuNculcutiN uiSu' II btcOy was Coi
rect what would it matter how the cooling
process was accomplished? [5] A chang
ing temperature produces convex motion of
the milk, and by this motion, and this only,
cream is brought to the surface. A few
simple experiments will, I am sure, convince
the most skeptical Cool two messes of
milk, by stirring, to sixty degrees set one
in room of the same temperature, and the
other in an atmosphere of fifty degrees. 1t
will be found that the mess receiving the
advantage of convex motion during fall.
ing temperature, will show the best separa
ton. 1t will be the same, cooling from fifty
to forty degrees and from forty to thirty de
grees. As thirty degrees freezes, will ex
plain little further, aud this explanation
and the facts connected herewith will, in
my opinion, forever settle the worse than
foolish theory that cream rises by reason OF
stationary temperature. [6] 1t is a fact
well known among dairymen, that milk
strained warm, into warm pans aud set in
room where it will freeze, shows a more
perfect separation of cream than can by any
other means be obtained. ri Of course,
in this case, the advantage of stationary
temperature is not experienced until after
the freezing points passed. 1t must, there
fore, be plainly seen that all the cream i.
raised while the milk is in motion, as have
stated. 1t is a scientific fact that fluids are
heated aud cooled by the motion of their par
Understanding to the natural law govern
ing them-and not by the conducting powe
which performs a like Office for metals. There
is still another experiment which has misleC
farmers as well as experimenters. This may
be tried by setting milk in large pans, witt
coolers at the bottom. After trial witt
water forty-two degrees cold, the atmospher,
of the room kept as nearly as possible a
fifty-eight degrees, after setting thirty-si'
hours cream globules were found in mill
drawn from the bottom of the pan, as larg,
and having the same capacity as those a
the top. In second trial-the air being thu
same and temperature of water sixty degree
"a better separation resulted, and the conclu
sion was drawn that the water in the frs
trial was TOO cold. But further expert
ment, using water at thirty-four degrees
showed an almost perfect separation. Nov
these experiments have been quite a STUN
bling-block to me, as well as to many of IN
brother farmers, and have spent much tim
in studying the causes which led to suc
puzzling results. Having satisfied myself,
am willing to give others the benefit of m
researches.
In the first trial the water used was forty
two degrees cold-the precise point whic
produces greatest contraction in a fluid. Blu
only small portion of the milk in the pa
is cooled, aud that at the bottom, where
will be found about forty-four degrees cole
To illustrate, we will suppose that five mi
lion PARTICLES of milk cover the bottom of tn
pan. By applying forty-two degrees of col
these are contracted, and the space is file
by PARTICLES from above, and this process r,
peated in each layer of particles until W
have-so to speak-a floor OF particles S
contracted that cream cannot penetrate an
rise to the surface. The fact that a larp
proportion Of cream remains in the milk a
the bottom of pans treated in this way,
another point against stationary tempe
atures. 81 The different result attaine
by using water thirty-four degrees cold
due to the fact that thirty-four degrees {
cold produced expansion instead of contra
ton, and caused an upward as well as dow
ward current in the milk until it was coole
TO forty-two degrees, at which point III
cream was removed and the separation foun
to be almost perfect; nearly all the but
raceous matter, not usually eliminated fro,
the milk, being separated. | wish all il
terested, whether advocates of one theory {
the other, to pay particular attention to tn
experiment; as thirty-four degrees of col
applied at the bottom of fluid produces
double convex motion [9] which is kept u
until all the fluid becomes of nearly the san
temperature This milk being skinned b
fore stationary temperature was reache,
and showing such perfect results, is anoth,
conclusive evidence against stationary tel
peratures.
That this would not be practicable We
for dairymen to raise cream is evident, as