New-York tribune., 1874-11-06

method or measuring electrca eHects, WHICH occur III
almost inconcevaby small spaces of time, was ex-
planned.
"WHERE DOES THE COLD COME FRONT"
BY Prof Elias LOomts.
The title of the first paper read to-day was
Results Derived from Examination of the United
States Weather Maps for 1872 and 1872 and 1t recorded
the results much panstakng investigation OF record
ed atmospheric phenomena, with view TO the discovery
OF laws governing the relation between the direction
and velocity wind and the pressure of the barome
ter. Incidentally, and curious theory as 10 the
cause sudden fails of temperature or "cod snaps
was deduced from these investigations quite at variance
with the received explanation OF cold currents OF air
pouring from tue polar zone This theory Is that
an overturning OF the atmosphere strata taxes place.
the cold air OF the upper aerial regions beng
upon the earth. In order to deduce from the
weather maps the law of the winds motion with
IN areas of maximum barometrlc pressure rroi.
Iooms selected cases which area or hlgn harom-
eter situated that the direction and veiociy OF
the wind was given al conslneraOe NUMBER OF staons
for at least half the area. Ihen, pdeing WrecIoss
across the weather map over the center OF an area OF
maximum pressure, VITA the wires pointing north east,
SOUTH and west, the area was divided INTO four Quad
rants, designated as the north east sOu.h ana @est
ouadrauts Then lie noted the velocity and direction OF
Inc wind as reported from the different stations within
each quadrant This process he appeu 10 Ios ulHcfeht
weather maps. All observations made near the center
OF an of ssure were rejected ana none were em
DOyed beyond the isobar 3o0J He then added the az
cregae OF observations for each direction OF tue
wind in the several qladrants and thus computed the
winds average direction for each quadrant Ine iol-
tions line being added TO snow the angle made by the
winds direction. with radius drawn from the point Vi
greatest pressure:
FOR HIGH BAROMETER.
" g 9oaS[It Ia. 2uaSt slt; 9nsdr, e 91ar.
Direct Of Winds g. 0E N296lE NSS ogK s5s3l5w
Inc Importance Of these Results will be os apparent when
low barometer, which were as follows:
FOR LOW BAROMETER.
91aiI! 9;Ia 2iaGiE < 91adlr. o1l.. 91aSi. ir,
Hsssioa Ds,ass Of SlGD slSsS i sl5$
An Fsr "ln hrG the average ange which the
winds make with radl drawn IRON the point OF greatest
pressure 400 49, for low barometer the average anglo
with rad drawn from the point .! least pressure 45
In each Gase Ine Gd rasd a
movement. variety OF inierences are suggested by
We Hsse he resryed others for future treatment The
eraqe velocity OF the wind for an area OF high barome,
norton of the Winds motion in the direction of radius
Is Al niles. This represents the velocity OF the out
ward flow OF air of high barometer at the
earths surface. Observations Mount Washington at
an elevation of 62S5 feet show tnat the law which pre-
there Suppose that the OF high barometer Is
circle 1900 miles in diameter that the barometer In the
center .at inches the velocity
of the entire column of miles hour, which
Is t1c mean between Veloctles observed on Mount
Washington and at the seaIevel. Assuming tnat me
average inclination to the radus is 420 o we find the
resolved portion of the wnas motion III the direction OF
radius is 1873 miles per hOur. mhat mus. oc 'o ehect
on the barometer of this outward movement OF air from
the OF maximum pressure i % less n s1aa tnfee ne
were movement III the upper regions OF the
atmosphere. Now, we KNOW tnat tncse areas VI nHh
pressure ha We considerable
fung without much change for 4hours, aud OCCASION
aly much longer. These facts appear 10 show con-
finua accession Of air from the upper regions In the
center OF an OF low barOmeter strong upward
movement been Observed, ana IL now appears GER
rain hat downward movement prevails over areas OF
biph barometer The result OF this downward now
mist he q considerable fall OF the Thermometer. A
series of observations OF tue lowest temperature Tor
each month IN 1872 and 1873 at New-hiV9D, COnl',
shaved that ip two-ihirds OF the Newaven was
included within Of high barometer ana hat IN
several remaining cases such an area exsied at
the West, and rapidly approaching that Guy Inese
appear to prove that the extremely low
which at irregular intervals III every
month and particularly In the Winter months are due
mainly 10 tine descent of cold air in the neighbor-
fr"m the outward movement which gener-
alIy takes place from the center OF an area
of hCD barometer Many interesting facts were cited
10 establish this hypothesis To show that 1t Is more
reasonable explanation OF sudden cold than the theory
of cold currents from the north sweeping over the
earth observations were referred 10 inade at
Melville Island latitude rs degrees north at hepsscaer
Harbor, latitude rs degrees north, ana at lrKutz IN
Siberia At all these places sudden falls OF the tner-
mometer going below the mean as has ever been
observed in this country. accompanied Win tle
same high pressure. II IL be Maintained hat the cold
sweeps down 10 from the north, whence does
n come TO these coolest Known points on the eaftns
surfacoi We are shut up to the conclusion that this
cold results from the descent OF the upper atmosphere
10 the surface OF earth In sum mer during huu-
der-sorm the temperature often fals l0' IN lew nl
hut show that there no current OF
air from the These sudden gusts OF coid must
descend from the higher atmospheric regions. 49,.
In the discussion which followed the ieaulng OF tn
paper Prof. Joseph Henry suggested the possiDy OF
sions in bringing down cold air which afterward
preciptated the earhs surface IN the areas OF neu
barometer where the outward motou VI the "ihu 10
observed.