n 
«'» » 
•ftte'Ssrs. Editors — 
I °fter to the public, through the medi¬ 
um of jour Journal, the following dia¬ 
gram or map, as a delineation of the north¬ 
ern verge, impressed from a wooden block 
carved with my penknife ; this, with the 
explanations, I present, rather as an ex¬ 
position of the constituent principles of 
mv Theory of the Earth, than as a collec¬ 
tion of proofs of its truth; still however,I 
arn^ induced to hope a minute observer 
wi‘1 find much evidence confirming its 
correctness couched in the explanations I 
adduce. 
The large, dotted circle, bounded on 
the lower side by the edge of the mapre- 
ptesents the locality of the real verge; 
the lesser dotted circle, represents the 
ridge of th e apparent verge: to this place, 
refraction apparently elevates and brings 
up the interior concave surface; every 
where between these two circles, a navi¬ 
gator, or an astronomer, should find the 
situation of the celestial bodies the same 
-Ryif apparent verge with its declina¬ 
tion was real and as if it existed without 
refraction; that is to say, the surface of 
the concave existing between the real and 
apparent verge, should, and it is con¬ 
tended does, appear unbent, or rather 
straightened out, and elevated by means 
of a degree of refraction (which may 
3eem to us extraordinary) to an apparent, 
continuous convexity, but gradually less 
and less convex. Beyond the apparent 
verge, there must appear to be a gradual 
a ling off in wardly, preserving, however, 
throughout the concave, from verge to 
veige, an apparent convex surface ; the 
space between the real and apparent 
verge must receive the sun’s rays very 
much weakened, owing to their being: 
greatly bent by refraction ; but it is not sS 
(accordmg, to the principle of this Theo- 
eyoml the apparent verge, for there 
the rays must fall more direct, and be re- 
is e n V n e, .h W 1 , m09t in ! ensit y- when the sun 
>S on the contrary side of the heavens It 
!, P rl, h»b |e that the reason the shadow of 
the earth on the moon appears nearly a 
true circle, even when the sun-anil m ~ ‘ 
are in the plane of the earth’s e(juator°is' 
