Had this globe been formed of one uni- 
I form substance-sand for instance—-of e- 
j qual fineness and weight, the whole sur¬ 
face of the globe would be one uniform le¬ 
vel, or perfect plain. Nor would it be 
subject to any changes in form, either on 
the surface, or internally. Their would 
be no eruptions, no volcanoes, no earth¬ 
quakes. No change could happen till the 
diurnal or annual motion of the earth suf¬ 
fered an interruption. Of these phenome¬ 
na the original cause is in the mixed ma¬ 
terials of the earth-and perhaps the yrox- 
j imate cause (as the doctors say) in the 
; rotary motion of the earth ; by which, 
II think, with Mr. Tufts, this globe first 
[ took its present form, and by which it fol¬ 
lows of course, that its form is sustained. 
Were the rotary motion of the earth to 
cease, I conceive its structure would be 
j instantly broken up, and, by the law of 
central attraction, it would collapse into 
a solid mass, the heaviest substances pres¬ 
sing most rapidly to the centre, ot not 
more, herhaps, than 500 miles diameter, 
or possibly much smaller. We know not 
how far matter may be expanded, or how 
much it may be compressed, when left to 
the power of central attraction alone.— 
Newton supposed that the whole matter 
of the universe might have been originally 
contained in a body of the size ot a nut¬ 
shell. 
I have long supposed the earth hollow, 
merely because a hollow globe would an¬ 
swer all the purposes et a globe, and a 
solid one would be a useless waste oi mat¬ 
ter; which is not agreeable to the econo¬ 
my of nature, as apparent in her works. 
But Mr. Symmes’ open poles are a subject 
I have not considered. 
Presuming you will publish Mr. i uit s 
letter, I have omitted some explanations of 
the rotary motion of the eaith, wui 
otherwise I should have made. - • ■ t5 * 
