1809.] Remarks on the Climate in North America, by Mr. Tatham. 9 
For the Mouthly Magazine. 
REMARKS o” the CLIMATE im NORTH 
AMERICA; with Obfervations upon cer- 
tain Effects of Froft in Mountainous Parts 
of the Country ; Methods ufed to preferve 
Fruit Trees, by means of Straw Conduc- 
tors, Fire,Pavement, © ¢c. by Mr. Tatham, 
T feems to be fomewhat generally be- 
lieved by the people in Europe, that 
the climate of the American-Continent is 
wholly regulated by its fpherical grada- 
tions ; for we frequently hear it obferved, 
that a place muft be hot or cold, fickly or 
healthy, becaufe it is fituated in fuch or 
fuch a latitude. ’ 
If the whole weftern continent, indeed, 
had been a continued plain, corre{ponding 
with the fauthern banks of North America, 
which border upon the Atlantic Ocean, it 
is probable, that this doétrine might have 
proved generally true; but as the interior. 
parts of the country ate not only moun- 
tainous, but greatly elevated above the 
common horizon, and formed upon a mag - 
nificent feale, we muft fearch for an auxili- 
ary principle of temperament: in more ex- 
alted regions than this imaginary level. 
The bountiful hand of Providence has 
conitructed things in America of a mag- 
nitude widely different from that upon 
which men are. accuftomed to obferve on 
the European fide of the fea; and when 
we enter a river of the Tranfatlantic hemi- 
fphere, which we find to be ten or twelve 
miles wide at its mouth, and afcend be- 
yond the flow of the tide until we approach 
a vilible inclination of river current fimilar 
to that which moving water affumes in 
every country as it approaches the ocean, 
we are naturally led to contider the pofi- 
tion which nature muft nave afligned to its 
fource, according to the proofs which we 
behold in an exifting refult of the philofo- 
phical principle by which the defcent of 
fluid particles is neceflarily governed ; and 
- we form our conception of its diftant ori- 
gin to correfpond with its cubic contents, 
and the angle of its inclination. 
Beyond fuch a rule for judging of an 
unknown fource, we have, at this day, an 
authentic knowledge of the topography of 
the country, as far weftward as the banks 
of the river Miffifippi; and, in fuch parts 
where the heights of land which divide the 
eaftern ftreams of that wonderful river 
from thofe which fall into.the Atlantic, 
have not been actually afcertained, we 
have, at leaft, the fuperficial admeafure- 
’ ments of the States, and the obtufe angle 
which is indicated by the ref{pe&tive ealt- 
ern currents, as the foundation of an ap- 
proximate calculation. 
Monruiy Mac. No, 54. 
Affuming this kind of data, we fhall be 
enabled to forma tolerable conjecture can. 
cerning the nature of that exalted fummit 
which gives rife to the unexplored waters 
of the rivers Miffouri,, Oregan, Miffifippi, 
and other divergent ftreams which are yet 
but partially known to us; and when, by 
this meafure, we are enabled to compare 
their vaft extent. and regular fupply of 
moifture, with what we know ef the lakes 
of Canada, which feed the rivers Ohio and, 
St. Lawrence throughout the thirfty fea- 
fon of a fummer’s drought ; we hall, I 
think, rationally conclude, that the high 
regions of the American Continent, which 
are hitherto unknown to us, contain vaft 
refervoirs of ftagnant water, collected into 
lakes and morafles, which the wifdom of 
Providence hath contrived as a permanent 
refource to fupply the perpetual demand of 
fuch unparalleled channels as are elfe- 
where unequalled, and are exceptions to 
the ordinary operations of natural philofo- 
phy ; nor need we be furprifed, if the ac- 
counts of circum-navigators fhould cone 
firm this ideal theory with future proofs, 
that reverfed winds produce fimilar wea- 
ther and climate to that which is preva- 
lent at the oppofite point of a central line, 
which takes its tranfit acrofs the higheft 
fummit of the land, from one fea to tha 
other. 
-This fuppofition is, I think, greatly 
{trengthened by the well known faét, that 
north-wefterly winds -are the moft power. 
ful and piercing of any which the people 
of the United States experience; and cer- 
tain it is, that winds in this direétion . 
traverfe the cold regions of the higheft 
fummit on the continent, and bring with 
them the frigid quality with which: they. 
are impregnated in palling over 5; which 
neceflarily purifies the atmofphere, and 
fubjeéts the parts of the country which are 
moit expofed to the winds blowing in this 
direction to the greateft dominion of cold, 
and to the fevereft effects of the chilling 
blaf. : 
In refpeét to the degrees of cold, which 
obtain a more powerful agency in a line of 
perpendicular afcent (if it ¢an be fo ex- 
prefled) from the common horizon, I be- 
lieve the philofophical theory is well un- 
derftood by the {fcientific chara&ters of 
England; but in refpeét to the confirma- 
tion of theoretic experiment by practical 
proofs, this is one of thofe grand and for- 
tunate cales in natural philofophy, which 
affords the moft fatisfactory demonftration. 
Thofe who have dared to foar above the 
clouds in a balloon have felt and teftified 
the gelid perception; thofe who have a- 
B fcended 
