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

water is greater than The hume
over land 81 we find
the velocity far
above The carih's surface much greater than lowe
down. Balloon voyages snow occasional Veiocltles
100 Miles PEI hour The hi2hest gales On the earll
surface rarely exceed eghty-nVe miles tnout
doubtless this has Deen exceeded III certain TORN
Goes and mon.eltary gusts, &C me curry uts on
q few hundred feel above the earth nave frequent
twice the velocity OF those observed on tue sur az
as SHOWN by observation OF the velocity oi passi
cloud shadows.
ward Immediately attend the areas wllhin whl
the lsObarIcs arr very near 10 each othef ana 9
away soon as these lines are seen 20 sepaTa
In the case OF yIoieat but very local storms I
stations VIII generally fan 10 give more ,iiah
general indication OF The dlstur Dance, anu hei,
Ii cannot be expected OF the signal bureau 10 =,
productions or probabilities 0i sucl locai u
turbanceS
TEE TEMPERATURE.
Although The average temperature Is hiSner W /
southern stations than at the northern ones, "a
higher in the daY than night time. yet ne weati
map VIII disclose mnunerable departures rom y
law, and Especially So II any great 0lAciehccS III
pressure or any eX.ended cloudlness exist
Tie temperature OF the lower air depends pl
marty, indeed, upon the amount OF heat pour
down upon the earth 10y the sun, ana ne anou
absorbed by ne aii, as the earIh radiaCes us ne
Dack nto space; hut, in addition TO TINS. tle ne
held latent N the vapOr that Goats III the ar Is
times liberated by the condensation OF lne sap
III log. rain and snow, ano then II becomes sen
be TO tne thermometer. Daring the day mo
atmo nheve Will become warmer than one thil Is VI
ana dur1ug the ngnt the radiatlon o. neat throu
a MOST atmosphere will DC less than that tnrou
q dry one. during cloudy or hay weather the la'
alton Is almost wholly cut OIL so thar very uniio'
temperature prevails on the oinef maui sul.os.
heat - a sorhea q. e., becomes lateht) IN tEe VI
cess OF evaporation TO materially rednce the tenn
peralure OF the air; so "drylng winds" are also
''coOlinE." An increase OF DarOnetric PRESSURE
by increasing the capacity OF the air ior moisture
serves 70 stimulate evaporation ana temporarily
reduce The temperature.
AGAIN, the lower strata OF ar receive heat from
the upper strata ana radtate PACK 10 theIu, 80
hot sf1at.s INV
part the result OF this Interchange. In the norman
condition Ut clear Ky me temperature above
should be less than tEat prevailing below Inc
abnormal CONDITION Is generally the consequence
q The elevation OF moist air luto the regions nig
above the earth aud the condensation OF lts mos
! tore consequent upon the expansion Oh the All.
! The undue heat tits generated IN vhe upper
| strata IS radlated down 10 the earth IS wen us
! out into space.
show that The ienneraturo varies much less over
cloudy than over clear districts; mat IL varies less
III l0lC than in elevated regions; that II Is warmer
on one side OF an area OF 10Y or hgh pressure
than the other. and generally tcdF2ntf M al
Ud~ce Of u"J storm cefttFe ana cotatr "a me
rear.
by attention 70 the position OF Tie areas OF
rislng and iallIng temperature we receive an
early mJMatl0u OF approaching storms.
TEE MOISTURE.
This important element is given in the bnlle
tins as a percentage Of iull saturatlon. Watery
Napor dlssolses III air very Ruch as salt us
solves III water, and as tAe salt IS deposited III
crystals whenever the water Is July saturated,
So ~ il with The atmospheric yapor.
One cube foot OF air, having temperature or
81 degrees and under unifcrm pressure OF 5000
lucaes, VIII hold .lS grains OF water wnen fully
saturated. IT. then we lower the ne, temperature
position OF q portion OF lie water, ana That either
III the form vi log, dew. rain, frost, CT snow and
haI. On The other hand II we increase the iem-
perture or the pressure, the air becomes capa-
bic Uf holding larger quantity oil yapOr and
ceases 10 he fully saturated.
Denoting illli Satuiation by 100 per cent and
absolute
map the relative moisture OF tue air al tie die
rent stations.
mai condition Of lae atmosphere decreases as We
ascend ABOVE the earth's surface. but The law OF
decrease IN cloudy and falling weather Is, or
course, different from that ia clear weather. The
dcgree OF saturaton oil the atmosphere increases
UP To the lower ciouu stratum, ana rapidly de
creases above the Top OF that stratum.
Fog ana dew attend the approximation OF inc
lover strata OF air. Rain and snow are merely
tie moisture deposited from supeisatufated
strata above TIE weather chart VIII snow Us
an increase OF moisture near bodies OF warm
water, hclds o snow, extensive forests ana
meadows, &C., as compared with dry plans 2ud
rocky mountains. LAe humidity VIII he lGnid
large ~ advance o. storm centres aud small IN
ihor rear. u wil be greater over warm, cloudy
districts than over cold or clear.
In ness will be found attending clearing up
weather. DaWpnesS almost Invariably preCedes
threatening weather several hours.
the CLOUDS AND The wEATHFh.
BY entering graphically on our map the gene
raj Ieatuies OF tie weather ana sky we complete
C0nduOu. The CLOUDS Dy their KINDS ana
changes are sIi index 10 the relative ienpera-
ture, moisture and pressure existing at high
attitudes; Dy Their motions they indicate the
nature o. The upper current o. ar.
Jhe casent OF expanding warm air gives rise
TO tie cumulus clouds whose nat bases are All
on pretty uniform level. These suhside ana
dissolve when they cease 10 DC led by rising cur
rents Of air. The cirrus clouds are probably
heat outward INTO thehgnest regions OF
the atmosphere, in which case they
are composed Of spicul@ OF Ice. and
they are also formed or the remnants OF
the storm clouds, In which case tBey are gen
orally composed Of warmer vapor Tue strong
winds that attend areas or low barometer
&C., as before stated, to ascending strata
OF moist air. In which, by expansion or
and rain clouds OF which we nave linc example
the castery OF the Atlantic coast. Tins SCI
cloud, which Is an amorphous cumuus, spreat
INTO broad sheets OF stratus.
Two LAYERS ol clouds almost invariably coexi
wherever extended rain storms prevail the upp
layer stretching far In advance 0i the lower b
descending ana Joining 10 the lower In the rear
the area over which rain IS FALLING. general 81
vev OF Inc map VIII show that cumUli or the cirtl fir
men toned are not inconsistent with fair weather.
A increased accumulation OF cumnl0us clou
becomes cloudy weather, but does not generally pI
sage the extended storms OF winter. The cirrus
the second class, sometimes called clrro-stratus
most always prccedes ct some distance the stOi
clouds Of winter and OF summer.
II we keep IN mind the existence or two inmen
hu 'Nci-Io" ihE tut tcu,a vi dui' "hc 'on ,hc ~
ana the other from the Equator one cold aud DIR
the other hot ana moist, we snail soon get q
quainted with the signs OF the weather. The air
The equatorial current ~ nghter than that OF q
polar, and 50 southcrly winds VIII begin TO bio
alOit before they are felt on the ground, WINE mort
erly Winds VIII begin 10 blow close 10 the groun
Accordingly. southwest winds give much mo
warning OF their coming than norihcastery ones.
The southwest wind Will often show itself first
long streaks OF cirrus clouds at great height, CALI
sometimes "Mare's Tails;" or wnen a gale IS We
near, 10y driving scud.
DR.. Gibbons noticed win great care at San Fra
cisco the the course OF the higher strata
ciOuds--the cirrus ana the very high stratns-wh,
they were visible. and found Dhcm 10 come uniform
IRON some westerly point as he hat also 0bServ,
tor many years at Philadebha. The writer h
long observed the same lactk in western New for