1800.} Remarks on the Climate of North America, by Col. Tatham. 12% 
lofophical principles which I have hereto- 
fore adduced are to be depended upon: 
the coafts of the continent (for inftance) 
from the mouth of the river Saint Law- 
rence, to Sandy Hook fouthwardly, are 
re(peétively near to high land, and at no 
great diftance from the main ridge of di- 
viding mountains, which feparate the 
ftreams of the Atlantic ocean from the 
waters of the river Saint Lawrence: this 
grand fewer of the whole Canadian coun- 
tries, again, is ftill nearer to thefe dividing 
mountains ; and Lake Erie (which is the 
lowe/? water of the upper country), cannot 
be much lefs than three hundred feet per- 
pendicular above the level of Lake Ontario, 
which is at the very head of the great river 
Saint Lawrence. Hence it is exceedingly 
clear to me, that nothing impedes the free 
circulation of the winds, nor the aétion of 
cold, in the purification of the atmofphere. 
But when we take our departure fouth- 
wardly from the highlands of Neverfink, 
and thofe of Staten Ifland, we bid adieu to 
an elevated country, and purfue a level 
coat from hence to the gulf of Mexico; 
for the entrance to New York is the laft 
fouthern latitude where the high lands ap~ 
proach the fea; and from hence they take 
a fouth weftero direétion in broken hilis, 
and continued high chains until they join 
the Allegania and Appalaches, and ter- 
minate among the fources of the Tombig- 
be and Alabama rivers, on the one hand; 
approaching the Miffiffippi on the other, 
not very far below its confluence with the 
Chio. 
Now, for the better elucidation of the 
degrees of climate which prevail through 
this vaft extent of level country, which is 
greatly fheltered from the diffipating blaft 
by a lofty chain of hills, which deferibe © 
its boundary on the one fide, while the 
ocean adjufts its limits upon the oppofite 
extreme ; I will endeavour to give a fcale 
of diftances, as nearly as my recollection 
of the premifes will permit me to afcer- 
tain the longitudinal admeafurements and 
direét lines to the fources of the refpeGive 
rivers; and between the banks of the 
ocean and the &ftle mountains, or firft 
highland countries, which thefe refpe&tive 
lines will approach jn their tranfit over the 
level lands. 
A Taste of direct lines, from given points upon the ocean, to the firft high- 
land interfe&tions; and from the mouths of the chief rivers to their fources in the 
principal mountains. 
<<<  RRVITC 
River line to |Miles to the 
ae ee ee —n— a ee  — — — —————————_:._—_00—_0—°00E eee 
Places upon the eSaliliog eerene oe 
Sd ee N. Latitude.| miles to high 
Coat. : land. 
oO P) um 
Neverfink. Oe Ora ° 
Cape Hinlopen. {38 o 46 125 
Cape Henry. 36 NO" 57 2co 
AlbemarleSound.|36 oOo 0 200 
Cape Hatteras. |35 7° 50 300 
Cape Fear River.l34. 0 0 300 




ean Ge Remarks. 
Miles. jHigh land at fea 
100 200. }UpDelawareriver 
200 250 Up James river. 
200 230 ©6©4Up Roanoak river} 
T-GO +, Hills. \Up,Neufe river | 
200 250 Up Cape Fear riv.’ 

From the latitude of Cape Fear to the 
fouthward, the country falls off ftill more 
level, and the lines of /atitude nearly mifs 
the highlands (a degree or two excepted) ; 
but in re{pect to the width of the level 
country, a line drawn from the mouths of. 
the feveral principal rivers to their fources, 
may be computed at about the following 
diffances, viz. 
From the mouth of Pee Dee river to its 
fource 200 miles.——From the mouth of 
Santee river to its fource 200.—-From the 
mouth of Savanah river to its fource 200. 
—From the mouth of Alatamah river to 
its fource 250.—From the mouth of (in 
the gulf of Mexico) Appalachicola river to 
its fource 300.—From the mouth of (in 
the gulf of Mexico) Alabama river to its 
fource 300.—From the mouth of (in the 
gulf of Mexico) Miffifipi river, follow- 
ing its general courfe to the falls, fay 10¢0. 
=~Ditte te its fource, fay 1502, 
4 
The greateft part of all thefe refpeftive 
diftances may be claffed as Jevel country 3 
and much contained in it (without efti- 
mating the Peninfula of Eaft Florida, 
which covers fix degrees of latitude, from 
25 to 34 inclufive), is interfperfed with 
morafies, {wamps and lagoons, retaining 
many ftagnant waters. 
It will be hence perceived among the 
abfolute caufes which may be fuppofed to 
influence a climate, that in fuch a vat 
{cope of low-fituated country as I have 
defcribed, it is not eafy for azy wind to 
make fo permanent an impreffion as would 
be dgmanded for a complete purification of 
the atmofphere: for when a fea-breeze 
blows, it meets the refiftancé of the folid 
mafs of the mountains, and muft become 
exhaufted for want of fufficient vacuum (if 
I may fo term it) to increafe its velocity, 
as would happen in croffing an ifland ; and 
if 


