Dallas herald. [volume] (Dallas, Tex.) 1849-1873, 1856-02-09
NO. AZ.
Tug Nonrnrss of Texas re great puzzle


they blow is evident enough upon the hypoth.
csis that the cold air of the winter, from the
plains and mountains Of the North, rushes in
to displace the warmer and lighter atmosphere
of the AIcx,can Gulf. This latter, in conse.
quence of lis reimclion, rises, and the colder
air from the North flows in 10 supply It's place.
Ii is held BY the learned that in the torrid
zone there is continual ascent OF air, which,
after rising, spreads itself 10 the north and
south, in an opposite direction to the currents
below; and that, these upper currents, becom.
! ing cooled at length descend and mix with
those below thus constituting what is known
rs the trade winds. Similar winds have been
conjecturcd 10 originate from the decomposition
Of the atmosphere towards The poles, from part
Of the air being coyer,ed into water. Those
views are, to the presen, day, in great de.
gree, merely speculative.
Winds are no; necessarily cold. The Phil.
osophical Transactions of the Royal Society
of London give a table Of the different veloci.
tics and forces of winds from which it appears
that the motion Of The mir moving At the rate
Of a mile an hour is scarcely perceptible; two
and three miles Just pcrccp;ibic lour and five,
gently pleasant; ten aai iieon brisk ;'twenW
to twenty-five, very brisk; thirty TO thirty-fvc
constitutes high wind forty and forly-ivc,
very high; fifty tn sixty, storm eighty to one
hundred, hurricane, tearing up trees and pros.
;Inting buildings yet the hurricane may be no
colder tiian the mir moving Il; the rate of five
miles an hour.
Cold is simply the absence oil heat 0. caloric
itself only hypocriticallv understood. This
last is said to urXist in Two different st tcs--frce
or uncombined, and in u state Of combination.
In the first, it causes the sensation OF heat, and
produces the expansion of other bodies. A
large quantity of free ca!oric in any substance
constitutes hcat---a small quantity constitutes
cold. However prone we mny be TO the oppo-
site view. philosophers ;c Us that our senses
are not sufficient 10 enable lis 10 decide as TO
the degree of heat or cold in different bodies ;
and, in proof, they cite us to The fact that the
same portion Of water will feel warm TO a
hand removed from contact with SNOW und
cold to another hand heated before the fire
This Is the reason, "" suppose, why We COM
plain more from TIC sudden descent oil the tern
peraiure IN the South 10 50 degrees than the
people Of the North TIA nt "stidGv cold" Of
10 degrees below 2ern. 'fhc difference, how:
ever, is not wholly Imaginary, Cor we have
known men 10 perish o cold in Texas; while
the mercury stood ahor" The trecaing point
We are 'utd thar ooulIpul, aHr atS,racCS caioTic
but tardily. II this b. true, our Sorlhcrs are
very uncommon airs. Dr. Fmnkln. Coun,
RumioEd, and Others, found that II vessel coated
with la.npback would give out its heat eight
times aS rapidly as linplatc, gold, silver or cop.
per. This is the reason the negro is SO much
H.,
or. Both liquids and solids, in their conver.
sion into varor or casscs, lose portion oi their
cnioric, producing what is known popularity as
cold, Heat is usually regarded as The cause If
evaporation, yet water IL converted into ,apor
at ,cty low temperature and, in the polar
rcGlone, Ice eraporatrs in The open mir. Evap.
omion itself is accounted for on Two different
hypothesis : the conversions Of fluids into elas.
tic vapor by their union with caiarc, und
real 9olunon of the fluids in the air De Luc
mot Le Duc) holds ,hat ia evaporation calort
is consumed, or combined with the cvapo'a'od
t.Ud and mUst thus produce sensible cold"
though we see no sense IN sTch cold rs ne
have had Of !a,c. Re further maintains ths,
air, Instead Of contributing 70 evaporation,
serves to prevent ii By pressure, and proves
this by The thCt that water cyapomIes more
rapidly in vacuum ,lan IN the air SaussuTe
says that, at the samc degree Of the therno M
eter and hyrrometcr, The evorora ,icn oi water
Is mare rhan double On monn'ains to that IN
valleys, where Inc mir is 'Arec tines The den.
sity.
The coidurys O, our Norhars, then, would
seem 10 resuIt neiheri'o tho simple motion
of the air, nor 'rorI e,apowtion; bu, simply
the transit Of lie cold air trrm laa monnnins
aaA h|cak plains OF the narth 10 the warm re.
-jon an the Mexican GGif.- G7i t'iriNca.