Delaware journal., 1828-10-21
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FoR THE DELAWARE JOURNAL.

TO the Editor, al
Sir a
By giving the following observations on winds, Il
place in your paper, you will confer avor r. on
the author OF them. JOSEPH b. HARltlo.
The earth is surrounded on all sides by an nvisi-
ble elastic, ponderous, compound fluid, which we e
call the air atmosphere.
This fluid is capable of being expanded by heat t
and contracted by cold. When expanded by heat q
its relative gravity is diminished when contracted t
by cold its relative gravity is increased we say Its
relative gravity, for its actual gravity remains the
same in both of these states.
This relative dIminuton the gravity OF the air
on the application Of heat and increase of it on the
! application of cold is the of wind.
Wind is a current of air created by the heavier
AIR pressing in upon, and pushing upwards the light
er air
The causes of wind must be sought for in the
agents producing the loss of equilibrium IN different
portions of the atmosphere and OF which there are
lnany-as lst the diversity of the earth's surface OF
sea and land the difference in the surface of the
land of yaes and mountains, the difference OF Gil
mates as cold and warm, sc. SC. but the great and
f principal agent, the OF nineteen tWeneths OIL
the winds that blow is to be found in rain.
: Let the atmosphere be cleared Of clouds, let no
rain descend to the eart and we should never expe
ricnce any other winds than the most gentle, stea-
. DIV and uniform breezes. ln the winter they would
4 be from the South West, West, North West and
= North principally in the summer from the East,
h South East South and South West principally. In
the spring from the East, and in autumn there would
VI be almost perfect calm for two or three months
These winds would originate principally 10 the
difference of heating and cooling of the sea and and
). they would all be light and gentle breezes they
: Would be steady and uniform, change mildly and
gradually and be of certain and fixed duration.
But let the amos sphere be loaded with clouds, let
deluees of rain decend from them to The earth and
IS an entire change will take place in the winds, and
r instead OF zephrys, shall have storms and temp
.s ests arising suddenly from all points, at all times OF
r. no fixed duration and alternating with Gains and gen
k tie breezes
Sc In order duly to appreciate the influence of rair
,r in the production of wind, will present to vie"
the case IN which its effects most strongly exeH
pied, viz : thunder storm.
These are the most sudden, the most violent ane
= of the shortest duration OF all empests, ana Inv
no doubt arises from the almost instantaneous pour
.rs ing down of deuges of cold water into the column
w. air beneath the cloud whereby an Immediate ant
no great condensation is produced IN this ar, al IN
ns same time that great degree OF rarelacuoh eAst
ted in the surrounding air.
M This condensed column OF air will rush INTO IN
surrounding air with violence proportloneh 10 VI
loss of equilibrium produced by the sudden AN
great condensation the one hand, and great rare
- faction on the other and will continue to move there
ia CARRYING WIN III tne Clouu uili a
the latter are exhausted, when it will gradual
cease 10 move from its becoming warmed and e'
e panded by its acquiring the heat OF the ar throue
90 90 which it passes.
loo The direction in which this column ofcondensf
air will move, will depend upon the state OF rar
faction Of the surrounding air and this being grea
est in South, West, II North or an last drectio
!, it will take either of these courses accordingly.
ket The cloud does not always follow the course
the wind and this is less likely 10 happenit it be
a South IA Vest or a North direction than 1t 1t be
easery one circumstance which merits iurth
consideration.
LIE, no aas,on,,, dnoot;nn Of tb;s we m
an convince ourselves by observing the motions OF
az then white clouds which float in it, which we sh
by iiho ~ pI ~ ~ H., t,a huan Of mar.
es in The spring of the year when they have alta
e,y ed certain elevation invariably move easterly,
~ the wind be blowing from whatever point 1t ma
ree This easterly motion Of the higher regions OF
anu atmosphere to be Slow steady and unltor
>. being very little affected by the movements OF
>" strata next TO the EARTH
If the whole of our horizon were to be overc
pro- with clouds and if in this state perfect calm we
eau' to ensue still the sky would soon become clear
: this clearness would commence in westward
"' rection, owing to the easerly movement OF the
:, bifcrous strata of the atmosphere.
81 Now it is this easterly motion of the higher re
- ons Of the air which causes the thunder cloud
move in the direction Of the condensed column
with air oener when that is its course, than when it
ENTs the South, the West or the North.
are 1t is owing likewise to the same cause that c
re- Of small extent seldom passes us, if it raise
orter ,ny other direction than due west
All rains will be productive of winds accordin
acter, hev are local or general as they fall in great
Della small Quantities, suddenly or gradually, by day
by night, in cold OF warm weather, on the lant
sgularI in the sea- from low or highly elevated c
and many other circumstances, in all Of which