THE 
PHILOSOPHICAL MAGAZINE 
AND JOURNAL. 
I, On the Mean Densily of the Earth. By Dr. Cuarres 
Hutton, F.R.S. 
»: Hae the determination of the mean density of the whole 
terraqueous globe of our planet, is admitted to be a problem of 
the utmost importance to several branches of philosophy, parti- 
cularly to physical astronomy, and the figure and constitution of 
the earth; it would seem, bbe the discor dancy of the declared 
opinions of some eminent philosophers, that the problem is still 
in an uncertain state. Since the first notice of this subject by 
Newton in his admirable Principia, it has often been incidentally 
alluded to without receiving a precise determination, with the — 
exception of two instances only, in which it has been stated to 
be certainly or approximately determined by experiment, namely, 
in the case of the Schihallien experiment, by Dr. Maskelyne and 
myself; and by the Hon. Henry Cavendish, by a method invented 
by Mr. Michell. 
The former of these experiments was made by Dr. Maskelyne 
in the years 1774, 1775 and 1776, by means of that large moun- 
tain in Scotland, in measuring its dimensions, and in comparing 
its attraction on a plummet, with that of the whole earth on the 
same; the calculations on the same being made by myself, and 
first published in the Philos. Trans, of fhe year 1778; ; and since 
more correctly in the 2d volume of my Mathematical Tracts. 
The other experiment by Mr. Cavendish, was by observing the 
attraction on small pendulous balls, of two inches diameter, by 
larger ones of ten inches diaméter, as compared with the attrac- 
tion of the earth on the same. 
By some strange mistake, or perversion, for many years, it was 
customary among certain persons, to withhold the mention of 
my ame, with regard to the great share that I had in the ex- 
periment on Schihallien. But from certain complaints which I 
have made, some little justice has lately been awarded to ne on 
that head; though still it would seem with reluctance, as the 
Vol. 58, No, 279, July 1821, ° A2 opinion 
