Edgefield advertiser. [volume] (Edgefield, S.C.) 1836-current, 1839-06-27
Miscellaneous.

Miscellaneous.
Professor Espv delivered on Saturday
evening the lUIh inst. at Clinton Hall, The
first of hi, lectures on The causes and for
nation of clouds and storms. About two
hundred persons we'rpresent, WIN listen
ed with great attention ard interest lie
commenced his lecture by SIaline The prInci-
pies from which his theory olme,e"ruloay is
deduced. These, he Observed were al
| really well knnwn to men of science. tho
their consequences had uot hitherto been
traced OUT. He showed that Ivy cooling
Tie atmosphere, at the surface of The earth
dawn to a certain degree of temperature,
i fog or vsi lc vapcr. or what in Il higher
region of the atmosphere is called cloud,
is always proluccd. This degree oftem-
prrature is called by philosophers the dew
,,on', aud il is higher or lower according
TO The qn'nli'y of moisture contained in
Tic atmosphere. II the atmosphere is
highly charged with moisture, slielh de-
.irc'i,le of .';a temperature will effect Tie
;h4asr: II il lie unusually dry. it must be
,.l;!, :, c,'i,iar:ahlv more. Professor Els.
py hen stated lie law Of temperatures
II :l.if".2 2rr heights Of the atmosphere. At
Il hunreh Sar;is abnve The surface Of the
ea:"'h, til" dir i i'nund 10 he Il very little
r.orr r!,tn ,us. degree Of Farrnhril's ther-
mutne'e er colder than al the surface of the
earth, twn hundred yards al little more
Than iva tlcglrcs colder, and so on, one
degree for every hundred yards that YOU
ri.r in the atmosphere. The air which is
rarlicl aml nadc lighter by the heat Of
The sun al ihr surface Of the Garth, there.
! fare, is cooled down to he dew point so soon
as ii arises 10 III" proper height from the
..rnund au; cloud is sproduccd Bnlihere
is anolI:rr cause which operates to reduce
the temperature of rariird air as it mounts
10 the higher regions of the atmosphere
Air suddenly expanded, always bcco'..;.s
roulrr. II by means of an =. pump, you
| exhaust :: receiver of half the air il con-
lains. he rcGaintier will immcdiaelv rx-
pand SO as 10 fill the receiver. aud at the
same time become ninety degrees colder.
Apply this principle TO column of water
ascending in the atmosphere. As il rises,
ii becomes relieved Ul Il portion of the at
mo>pheric pressure which it sustained AT
the surface, and consequently expands in
10 larger space, and becomes proportion
ably reduced in temperature.
From these laws Mr.. Espy proceeded
10 deduct. his theory of clouds and slorms.
which he did, so far as he proceeded on
Saturday evening, with much ingenuity
pertinent The formation Of a cloud IN Il
glass tube, by the mere expansion Of al
mosphcric air. He gave briefly The Gle
ments of calculation by Which The hei.hl
of the base OF cun!uusc cloud from rlI.
surface Of the earth, may be at any lirue
ascerlained by Il thermometer and Il
rumhler of wafer. He gave beautiful
theory OF hail storu's, showing them to h"
produced by ascending columns ofrariiied
air. which expand prodigiously as they rise
in the atmosphere and throw off the hail
on each side, from the edges of the cloud
and nnl from its centre. II is owing to this
cause that hail storms fall. as is observed
10 he The case, in tracts with intervals be-
tween thcm. Concerning the relation Of
winds to storms, Mr.. Espy observed, thai
il has hcen fully ascerained that they
blow iIon all sides towards the tract Of
country where the storm is generated;
while in that tract there is nearly or al
most calm. He gave several examples
of storms extending over considerable
tract nfcountry, in regard 10 which il had
been fully ascerlained that the winds blew
towards Them from every quarter of the
surrounding region where the storm was
not fell.
In his next lecture, Which is delivered
TO night. Mr.. Espy proposes 10 unfold his
method Of predicting storms, and this and
his subsequent one will be devoted to
The practical application Of the principles
laid down in The first. They will, there
fore, probably he more entertaining TO
general hearers.
Professor Espy's manner is cnlloquial
and clear, his enunciaion is little too
rapid at times, but never iuhisIinct. He
is evidently profoundly acquainted with
his subject, and we have no doubt has
made discoveries in relation TO branch
of natural phenomena hitherto moi reduced
To exact principlps-liscoveries valuable
10 science, autl useful in practice. He is
TO visionary weaver of fanc!fnl theories,
bul man of science, and patient ques-
toner of nalure.-N. Y. Eve. Post.
Bravely 10 contend for n good cause ia