The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1871-08-06

water is greater than The Nume
over land we fnd
the velocity far
above The earih's surface much greater IMAM lowe
down. Balloon voyages snow occasional Velocltles
100 mile, nc. hour The highest gales on the eartn
surface rarely exceed eShty-nve imles, tnoue
doubtless this has Ueeu exceeded III certain TORN
does and mon.entary gusts, &C. me CUR Jus on
a few hundred iect above the earth nave frequent
twice tue velocity OF those observed on the sur ac
As SHOWN 10y OBSERVATION OF tue velocity Oh passli
cloud shadows. .
ward immediately attend the areas wIhin wh,
the lsOharlcs are very near 10 each other ana y
away 50 soon rs these lines are seen 20 separil
In the case OF voleat but very local storms q
stations WIN generally fan 10 give more tiah
general indication OF the disturbance. ana nei.
II cannot DC expected oI the signal bureau 70 Z,
predictions or probabilities Ol sucu local "a
turDanceS
TEE TEMPERATURES.
Although The average temperature II higHer ~ "
southern stations than at the northern ones, III
higher in the daY than AT night time yet the weat
map Will disclose mnumerable departuieS from U
law and Especially SO II any great diheiehces III u
pressure or any extended cloudIness exist.
The temperature OF the lower ar depends pi
marily, indeed, upon the amount or heat pours
down upon the earth 10y the su1, ana me ainou
absorbed by ne ALI, as the earIh rauiates us ue
back INTO space; but In addition TO tilS, inc :, ne
held latent N the vapor that noats IN the air Is
times liberated by the condensation oil the vap
In Fog. raln and snow, ana then II becomes sen:
be 10 the thermometer. Dating iae DAY mo.
atmo rhere Will become warmer than one that Is or
ana durug the night The radiation Of heat tnroul
L mos. atmosphere Will &c less than llat ,.liout
dry one. during cloudy or hay weather tue lst
alton l. almost wholly cut OIL so that q very ulIov
temperature PREVAILS ON the otnef manu- suinoic
heat Is 4 tsorpeu &. e., becomes latent in the pr
cess OF evaporation 10 materially reduce tine tem-
peTature 81 the air; so "drylng winds are ALSO
''coolinE." An increase OF parometrlc PRESSURE
by ncrea ing the capacity OF the ar ior oistuIe,
serves tosumulate evaporation ana Temporarily
reduce The temperature.
AGAIN, the lower strata OF AR receive neat lronh
TIE upper strata ana r:idIate back To them, SO
thai the temperature on the earths surface Is III
part the result OF this interchange lnthe norman
condition VI clear SKY Inc temperature above
should be less than tEat prevailing below. Inc
abnormal condition s generally the consequence
Cl The elevation OF moist air utothe REGIONS ntgh
above the earth aud The condensation OF its mos
tore consequent upon the expansion Oh the ai..
! The undue heat thus generated IN the upper
strata - radiated down 10 the earth Is Wen as
Oui INTO space.
me examination or our weather chart VIII
show thai The temDerature varies mucn less over
cloudy than over clear districts; mat II varies less
III lor Than in elevated regions; that 1t IS warmer
on one -idc OF an area OF 10Y or hisn pressure
ihan the other. anG generally trd1W.r az az
cd~ce % 0ay Storm ce'ttTe ana co1r ia me
Tedr.
BY attention TO the position OF tie areas OF
r.s.ng and filling temperature we receive an
early IntIMGtton OF approaching storms.
TIE MOISTURE.
This important element is given IN the hulle
rims as percentage OF iull saluratlon. Watery
vapor dissohes in ar very mucn as salt dis
solves III water, and rs Tie salt is deposited IN
CRYSTALS Whenever the water Is July saturated,
one cubic FOOT " air, having temperature OF
50 degrees and under uniform pressure OF 5000
lncaes WIZ hoa s grams OF % ,ae w,ep luy
or the pressure ~ the air there VIII result de-
position OF portion OF The water, and that either
III the form vi log dew. rain, frost, CT snow and
hai. On The other hand, II we increase the Iem-
perlture or che pressure, the air becomes capa-
bic u holding larger quantity OF vapor aid
ceases 10 he itllly saturated.
Uenotlr. iuli SaturatiOn by 100 per cent and
absolute drJDess by zero, We indicate Oh our
map The relative moisture OF the air al tie dido
The absolute quantity Of moisture IN the nor
maj condition OF tae atmosphere decreases as We
scend aSove the earth's surface. but me law OF
decrease IN cloudy and falling weather Is, OF
course, inherent from tia; in clear weather. The
Gogree OF saturatgoa OF the atmosphere increases
up 10 the lower cioud stratum. and rapidly de-
creases above The top OF that stratum.
Fog aud dew attend the approximation OF the
lower strata OF air. Rain and SNOW are merely
the moisture deposited from supefSaturated
strata above. Ihc weather chart VIII SHOW u
au Increase OF moisture near BODIES OF warm
water. nelds o; snow. extensive forests aud
meadows, &C., as compared with dry PLAINS aud
rocky mountains. The humidity WIZ be found
iher rear. IL VIII 90 greater over watm cloudy
districts than over cold or clear.
DR. ness VIII be found attending clearing up
weather DamPneSs almost invariably precedes
threatening weather several hours.
the CLOUDS AND TAE WEATHER.
BY entering grlpnio1ily on cur map the eene-
RAJ features OF tie weather anu SKY we compete
our detailed representation OK the ATMOSPHERIC
Conauou me clouds Dy Their kinds and
changes are sn index 10 the relative temporal
ture, moisture and pressure existing at high
attitudes: by their motions they indicate tae
nature OF The upper current 81 ar. -. -.
The casent Of expanding warm air gives rise
to tile cumulus clouds. whose ilat bases are all
on a pretty uniform level. These suhSlGe ana
dissolve when rney cease 10 pe lea " t1silg cur
rents OF air. The cirrus clouds are probably
formed independently ny tue radiation OF
heai outward into thehgnest regions q
tue atmosphere, in which case they
they are also formed or the remnants OF
tue storm clouds, in which case tIey are gen.
orally composed Of warmer vapor. The strong
winds that attend areas OF low barometer
give rise, through the influence OF friction,
&C. as before stated, 10 ascenn,ng s,raIa
cooling, a. tile ease may be, are produced the Sou
and rain clouds Of which we have rnc example !
rAe clsteriy rains of the Atlantic coast. Ems sou
cloud, which Is an amorphous cumulus spread
INTO broad sheets ~ stratus.
Two layers oi clouds almost invariably cocks
wherever extended rain storms prevail, the uppe
layer stretching far IN advance Oh the lower, b'
desg ending and joining 10 the lower IN the rear
the area over when ram y ialilng general s su
vev OF the map WI show that cumu or the cirri hr
mentioned are not inconsistent with falT weather
An Increased accumulation OF cumuous clou'
becomes cloudy weather but does not generally pr
sage tile extended storms OF winter. The cirrus
the second class, sometimes called cirrostratus.
most always prccedes at some distance tue stosl
, clouds OF winter aud OF summer.
If we keep IN mind the existence or TWO INN en-
ana evor-ro~lng currents Of air, one from the pc
anu Tue Otntr lrVui the Equator, one coiu anu or.
the other hot and moist, we shall soon get q
qualnted with the signs OF the weather. The air
the equatorial current u lghier tban that or "
polar, and 50 soutlerly winds Will begin to bio
alolt before they are lelt the ground, whe nort
crly winds VIII begin 10 blow close 10 the groun'
Accordingly. southwest winds give much inol
warning OF their coming than norihcastcrly ones.
The southwest wind Will often show itself first !
long strCahs OF cirrus clouds at great height Gale
sometimes MARES Tails;" or, when q gale IS vel
near, 10y driving scud.
mr. Gibbons upriepQ with great care NJ san Era
cisco the the course OF the higher strata
ciouds--tne cirrus anu the very high stratus-whe
they were visible. and found Dlcm 10 come uniform
from some westerly point, as ne hal also observe
Tor many years at Pnilade ihia. The writer M
long observed the same Iacf in Western New for
where al average OF not iQQte than one tnstans