077) 
the Inner. Thus the Diameter of the Earth being about 
eight thoufand Englijh Miles, I allow five hundred Miles 
Aot thethicknefs of its Shell, and another fpaceof five 
hundred Miles for a Medium between; capable of an 
immenfe Atmofphere for the Ufe of 4 the Globe of Fe- 
rns : Venus again I give a Shell of tha&m^;tHicknefe, 
and leave as great a fpace between her* CdncflVe and 
Mars 5 fo likewife from Mars to Mercury, Vvhich latter 
Ball we will fuppofe folid,and about two thoufand Miles 
Diameter. Thus I have fhewed a poffibility of a much 
more ample Creation, than has hitherto been imagined ; 
and if this feem ftrange to thofe that are unacquainted 
with the Magnetical Syftem, it is hoped that all fuch 
will endeavour firft to inform themfelves of the Matter 
of Faflr, and then try if they can find out a more 
fimple Hypothefis, at leaft a lefs abfurd, even in there 
own Opinions. And whereas I have adventured to make 
thefe Subterraneous ©rbs capable of being inhabited,.. 
*twas done defignedly for the fake of thofe who will be 
apt to ask cuibono^ and with whom Arguments drawn 
from Final Caufes prevail much. If this fliort EfTay 
lhall find a kind acceptance, I fhallbe encouraged to en- 
quire farther, and to Polifli this rough Draft of a Notion 
till hitherto not fo much as ftarted in the World, and of 
which we could have no Intimation from any other or 
the Vkmomena of Nature. 
Since this was written, a Difcovery I liave made in 
the Celeftial Motions, feems to render a farther ac- 
count of the Ufe of the Cavity of the Earth, viz. To 
diminifti the Specifick Gravity thereof in refpe£tof 
the Moon : for I think I can demonftrate that the Oppo- 
fition of the Ether to the Motions of the Planets in long 
time becomes fenfible: and confequently the greater Bo* 
dy muft receive a lefs Oppofition than the fmalkr, un- 
lefe the Specifick Gravity of the fmallerdo proportion- 
ably .exceed that of thegreater> in which cafe only they 
can- 
