782 Mr. hutton’s Calculations to of certain 
ftru6ture of the hill. And the ealieft method of doing 
this would be to procure holes to be bored, in feveral 
parts of it, from the furface to a fufficient depth, after 
the manner that is practiced in boring holes to the coal 
mines from the furface of the ground; for by fuch ope- 
ration it is known what kind of ftrata the borer is pafled 
through, together with their dimenfions and denfities. 
The proper mean among all thefe would be the mean 
denfity of the hill, as compared to water or to any other 
fimple matter; and thence we fhould obtain the compa- 
rative denfity of the whole earth with refpect to water : 
but in the prefent inftance, we mu ft be fatisfied with the 
eftimate arifing from the report of the external view of 
the hill ; which is, that to all appearance it confifts of an 
intire mafs of folid rock. It is probable, therefore, that 
we fir all not greatly err, if we affume the denfity of the 
hill equal to that of common Hone; which ds not much 
different from the mean denfity of the whole matter near 
the furface of the earth, to fuch depths as have actually 
been explored either by digging or boring. Now the 
denfity of common ftone is to that of rain water as 2 ~ to 
1 ; which being compounded with the proportion of 9 
to 5 above found, there refults the ratio of \\ to 1 for 
the ratio of the denfities of the earth and rain water; 
that 
