The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1852-02-07

| until the 25th of February next.
The ion was put, but no quorum voting, the
question was not decided.
The meeting, at 10 minutes past IL o'clock, then
| adjourned to meet on Monday evening.
| PROFESSOR GUYoT's THIRD LECTURE at the 1.-The
neum, on Thursday Euening upon The laos that 60
vern the Distribution Of RAIN and Moisture the
EartRs Surface, and the Effects thereof upon the
Phenomena Of Vegetation. when we entered the
well filed lecture-room on Thursday evening, the
Professor just concluding his calculation of the
cause and effect of vapors. The atmosphere, he
said, always contains vapors-sometimes in large,
and sometimes in small quanttes-and this led to
the inquiry to the cause of rain-to answer which
we must ask for the cause Of condensation. Tempe
nature the regulator. If the temperature be-
came lower, the capacity of the air to hold vapors
was diminished, and rain was brought down sooner.
If the temperature high all the vapors dissolved
and therewas but little chance for rain The warm air
from the Southwest contained more vapor than the
| cold air from the North, and when they met to-
| gether, the vapor Of the air became con-
| densed, and necessarily there was fall of rain
Vapors assembled to the higher parts of the atmos-
| phere, because they lighter than the air-and
| there formed clouds.
| The mountains exercised great influence upon
rans-the Andes for exo mple. The moist air struck
against the Andes and the lower air forced it to as
cend, and coming in with the higher and colder
layers of air along the tops of the mountain, the
warm air became condensed, and along the slopes
| there were great rans-when, 10 the plains below
| there was scarcely any rain.
| ttvo ~, a. tL,o
| tributon of rain was quite different Each had pc
culiar causes of condensation-and these were the
| tropical and temperate zones. In the tropics i'm
mense quantities OF rain fell in very short periods of
time-particularly when the sun was vertical.-
Twenty-one inches of rain would sometimes fall in
twelve hours. In these instances the heavy rain
was occasioned by the powerful heat causing the
ascending of air to destroy the horizontal
| currents accompanied by vapors and to arise much
higher than the cold layers of atmosphere and form
ing into immense clouds, descend in masses ofsrain
In the region where the trade winds met there was
zone OF Gains where the winds did not blow, and
here because of the ascending currents, there
constant thunder storms. Ia this zone of cams the
water fell during the year to the depth of one
hundred and fifty inches Mr.. G. then proceeded to
show, by description and illustration that at the tro
pics there was the greatest amount Of ran-that
amount diminishing as one proceeded northward -
At the zones of calm rain fell during the year tothe
depth of one hundred and fifty inches-at other
points of the tropics Que hundred nches-the region
of Florida fifty inches-New York forty inches-St
Louis thirty inches-Arctic region ten inches
Where the largest amount of rain fell, the number
of rainy days was 1ess-and greater where the
c,1t ~.
days rain in the tropics and two hundred in the po-
lar regions The difference of the amount of rain in
the winter in the temperate regions, from the
amount in the sunmer-was illustration of the
difference in the amount of rain that fell at the
tropics and in the cold regions. Explanation was
then made by the lecturer of the canse of the i'm
mense drops that fell at the tropics The rain fell
from the height of 1000 feet-the drops becoming
larger and larger they fell through the masses of
vapor. In the colder regions, the clouds of rain
were nearer to the earth, and the drops smaller
There were many exceptions to the great rules for
the distribution of rain. On the coast more rain
fell than in the int erior, and this was owing to the
form and position of the country. A contrast was
then instituted between the Old and New World, in
regard to the amount of rain that fell in both re-
gions. In the New World, at the tropics one hun
bred and fifty inches of rain fell while at the same
place. in the Old World, only seventy seven inches
fell. This owing to the continental or relative
FORM of the couatries-to the simplicity of struc.
ture in the New, and the complicated form of the
Old World
The Professor here enlarged upon the effect of
these heavy rains-contrasting the immense and
luxuriant vegetation of the regions favored with
penteous rains with the scarcity of vegetation ofthe
colder countries with less rains.
Mr.. G. then gave very interesting account of the
distribution of rain and its effect upon vegetation in
South Notwithstanding upon the cause and
condition of seven different regions, four of the ill.,
terror, and three of the mountainous regions-hav
ing different notifications of rain, temperature and
vegetation. For instance, Patagonia In that eoun-
try there plains eight nine hundred miles in
extent They had slight sains, feeble vegetation
and its inhabitants were of the lowest type Why
wasits The great trade winds from the West
could not cross the snow-topped Andes with their
moisture-and the plains beyond were, therefore.
destitute of vegetation. On the contrary, on the
Western side of the Andes, Terradel-Fugo for in
stance, vegetation was most luxuriant Perpetual
rains there causedby the vapors coming against the
walls of the Andes, and being condensed in great
clouds, they fell in masses of rain The island of
Chloe was remarkable for fertility and receiving
greataad constant rains. In fact it said of it,
that il rained there six days in the week. and show
cred on the seventh, One could there walk on the
top of vegetation--and between interstices peer
through to the ground at distance of fifteen feet
The plains openingto the Atlantic then spok
of This opening led to the reception of vast
quantity Of moisture from the ocean, causing rains
and fertility. In connection, the influence Of the
Amazon and great rivers of South America was re.
ferred to-
In concluding, the lecturer adverted to the cont
nenf of North America, applying the rules he had
before laid down, and noticing the Iexcepdons-as.