The Caledonian. [volume] (St. Johnsbury, Vt.) 1837-1867, 1840-07-07
.ARTIFICIAL RAIN.

MIR Espy far outstrips Xntippe in the produc,
ton OF artificial rain-as will be seen by the fol-
lowing Interesting letter from that gentleman
published in the National Gazette.
TO the Friends Of Science in the United STATES
! continued to hope that might he abs TO pub
lish work on the "Phiosophy Of Storms, y
which is tow very nearly ready for the press
before I sailed for Europe; but as 1 now find il
impossible 20 do so in time TO meet the British
Association ut Glasgow, OH the 11ll of Septenl-
Der, have determined o leave wih'the editors
Of the National Gazette, for puhicaton after
my departure, very brief summary oflny the
DRY OF storms, &c. My work will bntain nhun
dans facts to prove all the principks contained
in the summary.
The numbers used in this paperare not inten-
died. to he any thing but near approximations to
the truth; they will serve howeveito show that
Meterology will soon take its RAM among the
exact sciences. AS to the POSSIBILITY of produ
cling rains artificially, in time of dpugh, learn
ed from MAJOR Tenney and Mr. O@en, of Lou
isiana, that they had both separately tried the
experiment last summer, in tine of drought
with entire success. Maj. Tehey saw the
cloud form over the fire and the r;sl come down
through the clear blue sky below and MIR Og.
den informed me that it rained ornll his neigh
bors east of him. but not in the vest. One Of
3
which had been cut down to cleai his land and
the other had salt mash on the west of his
farm, which burns freely i'm time drought.
request gentlemen who may hive the means
ofrying this experiment during ny absence, to
send an account of their success & failure, to
William Hamilton, ESD, Actuary IF the Frank
lin Institute, Philadelphia. They must 81, fire
to their materials only WREN all he following
circumstances occur. A drought- "a calm mir
or very gentle breeze from the eastwar,l-a
clear day, and a high dewpointi This latter
may he ascertained by putting thermometer
(Fahrenheii) into n tunbler of water, and find
ing how many degrees it will haveto he below
tho temperature of tho mir from !2 to O'Clock;
i'm the DAYS that the vapor in the or will con-
dense on its outside. The highef temperature
NJ which it will condense is called the dew
point and il it should not be MOB than ten de-
grees below the temperature othe air at noon
il may be considered favorable; ad II II should
he less than ten degrees it wout be better. /
hope this experiment will he rseate,lly tried
this summer, and the news OF success reach me
in a foreign land. ae'
IL it should succeed, it is prohble the rain
will widen ont from the place Pf beginning,
moving eastwar,lly or south ea$vald until 1t
rcache tn the Atlantic, not rainin much if any
west of the place OF commemorate. Nothing
however but experiments can letc these points
and others which might be ntneh, such AS
whether steam powee.: in the air nay be SO kept
down Ivy regular artificial rains aso prevent the
possibility OF tornadoes and distinctive hail
storms, which can only occur Ylen the dew
points AFRO high. e''f ~;
When return from Europe shall immedl'
ately examine all The records Of orms, whether
natural or artificial which may sent as re.
quested above. In the mean tine, remain
your very humble servant, JAEs p. EspY.
PHILADELPuIA, June 9th lS4.