[ 62 3 ] 
by a company. The Abbe Barthelemi has read very 
well a page, -except a few words, which he had not 
time to fludy, The account of the manufcript on 
mufic is true. 
The meafures of the Abbe de la Caille, and thofe 
of Father Maire and Father Bofcovich, whofe 
book muft now be in the hands of the Royal Society, 
do not agree with the elliptical curve of the meridian, 
or with the circularity of the parallels. And the 
earthquakes felt on the fame day on all the coafls of 
Europe, and in Africa and America, at Ancona, 
Morocco, Bofton, and in the Baltic, may contribute 
to convince thofe, who fhall doubt of it, that the 
earth has immenfe cavities, and that it is very hete- 
rogeneous, or rather of a very unequal denfity. Con- t 
fequently its figure is a little irregular ; or, if the cur- 
vature be fuch, as the laws of ftatics feem to require 
in the hypothecs of homogeneity, that figure muff 
be altered by changes happening in the internal parts 
of the mafs. It was at firft fuppofed to be fpherical, 
and the orbits of the planets were confidered as circu- 
lar. It was afterwards found, that they were ellipti- 
cal, and the earth an elliptoid. Every ftep made in 
the ftudy of natural philofophy has di (covered l'ome 
apparent irregularity, according to our manner of 
conception. The refractions, the aberration of light, 
the nutation of the axis of the earth, have all been 
reduced to a calculation. Afterwards was found out 
the irregularity of tire refractions upon final 1 emi- 
nences, which perplex aftronomers. The hetero- 
geneity of our globe will puzzle the mathematicians ; 
and earthquakes will perhaps do fo more than all the 
reft. I have probably obferved to you before, that 
4 K 2 I am 
