The evening Argus. [volume] (Rock Island, Ill.) 1861-1871, 1866-03-30

Thus there is vast dItference SeswesH wv
Transparency of bodies, ana sneE power VI
transmitting heat. AGAIN tnsre are oef'ain
hos;ss vh;eh reiees heat of different refrsng |
;n;l;.. Snow sor instance, which reflects
I;yht Of ali degrees of refrangibility. rejects
hss, o,Iv of certain degrees. We don't, |
,hsr.fass. get much information when mere. |
10 tod that .'ice, like glass and air, is good |
CONDUCTOR of heat"
..Glacies'' illustratively telling US that
when s.the air is colder than the water, the
heat IL thrown into tho air." This, to con.
siderable extent, is true, for heat 10 very gen
erous, prone to comfort It's cold nelghbors.-
But he, no doubt, knows that air lets heat
pass dcvnwards much more readily than up.
wards. Tho atmosphere acts, like an envsl-
ope, which is easily pierced by the soiar
rays. bat which offers considerable resistance
TO the radiant heat escaping from our earth
it's action resembles that of a valve which
allows LIQUID 20 pass freely in one, but stops
the fl w In the opposite direction"
s.Glacies" assumes that in spring the suns
rays pass through the ice and raise the tenn
perature of the water below, aud that this
elevated temperature of the water melts thu
superinoumbent ice. Does the temperature
of water in contact with ice ever rise above
800? "a given weight of water at 172o,
mixed with an equal weight of water, at 320,
will acquire a mean temperature of 1922:
while water ct 1720, mixed with an equal
weight of Ice at $50 will be reduced to 320."
In support of his theory, ''Glacies" tells ms
of the ice in the process of disintegratiOn,
falling Unto neede-like pieces, tinkling in
the fall like tiny BELLS" And then be speaks
of the heated water or the lower surface Of
| the ice ''rising up through the ice and sepa
| rating it into delicate cylindrical pieces."-
Let us see how much disintegrating force
| there is in all this.
| Water has It's maximum density at 409.-
| Above that heat expands, below that cold
| expands it. To account for this exception to
| the general Law, that bodies are contracted
| by cold, various experiments have been made
on the physical properties of ice by DIR. Tyn-
| dell and Others The following quotation
may, perhaps, throw some light on the Soy
| indrioal pieces" and the supposed watery
air bubbles of ''Glaces :"
| seWhen a sunbeam, concentrated by a lens is
! allowed to fall on piece of apparently homogen-
eous ice, the path of the rays is instantly tded
| with numerous luminous spots like minute a.-
bub bles and the planes of freezing made ma nj
fest by these and by small assures. Stars, W.
like figures of six petals appear parallel to the
| planes oftreezing, and seemingly spreading out
! from a central bubble. These flowers formed
| of water When tho ice is melted in warm water
no air is givea off from the bubbles, they seem
! to be vacuums; II is, however, possible that
foc for the melting points of ice might be dIssov-
| ed by the water soon they came in coBtaCi
with 1T. Be this II may, the existence OF these
| points throughout the ice, where IT gives way to
the heat the solar ray, If IL does not prove actu-
al vacuums srform spaces to exist in ice proves
that it ia not homogeneous, that its structure j,
probably definitely crystalline, and that the mat
ter com posing it is in different degrees of aggre.
cation, that its mean specific gravity might
| well be less than that OF water
Tho chief ;rdnapca IF the alar,apt m tbs
Toe is not thermal. but mechanical, wsarin z
smoothing, polishing. till ittle for friction IL
left, as may be seen Ia these masses which
are piled up on the banks, and this meCbani
oal action. IN part, accounts for the breaking
up of the Rock Island skating park, which
had been located partly on sand bank nee
essarily causing an inequality in the cur
rent.
"Glaoies. b" in his last paragraph, has for
goa himself. lie says 1.-THE ice outside Of tht
skating parks had got large volume, for
while the skating parks were scraped ana
kept free from ali snow, the ice outside re-
tanned the snow, which, with the addition Of
the falling rain frOze upon it's surface y
Why, any farmer will tell him that az inch
or two Cf Stow on the sGrfacs will keep she
ice from getting volume and protect his late
sowr field and that if he wishes the leo Il
get volume, he has only to do what was done
, 10 the skating prrks-scrape on the snow.--
i moments thought, and "Glacies" mus
see that the reverse of his statement Ia tht
, truth The snow on the ice outside tn,
parks tended to restrict the volume Tht
sweeping of the snow from the parks, would
IF itself, increase the volume Of ice, eyeE
though they had not been, as they were, food
ed. night after night.
am not likely, Mr.. Editor, to trouble
you further on this topic, but / hope "Gla
cios" will cut up the blunders he finds il
I this.
''Glscies" and l are united in best wishe
, for navigation and skating parks, but wheth
or this means the destruction of either o
= them remains 10 be determined On that &c
termination this discussion ia not likely Il
: have much effect, but it may yield SOM
! pleasure and little mental Improvement +
those who engage in il.
. Yours, &c,
I0TA.