[ 7 * ] 
require fo great a number of aftronomical and geo- 
graphical obfervations, it will be thought, that an 
error a little larger may be fuppofed, without difpa- 
raging either our operation, or Mr. Picard’s j and thus 
theory and experience would agree. 
Suppofing, for example, that the difference be- 
tween the degrees of Paris and Tornea has been found 
too great by 80 toifes, the difference between the 
two diameters will come out of about —£-5, which, 
fubtradted from ytj gives 7— for the diminution of 
the gravity from the pole to the equator. And fuch 
a conclufion would agree pretty well with the obfer- 
vations made in France and Lapland with the excel- 
lent clock of Mr. Graham. 
However, altho’ the errors to be fuppofed in the 
operations, to reconcile them with my theory, be in 
themfelves fmall enough, I fhall abflain from affert- 
ing, that they have been committed. It is a fadt 
not to be decided, till after the refult of the ob- 
fervations, which are expedted from Peru. For 
the great difference, which is to be found between 
the degrees of Quito and Tornea, is the only means of 
knowing, whether the diameters be lefs or greater 
than 230 to 231. 
Were the queflion only to demonflrate the flatnefs 
of the earth, the meafures of the degree of Paris and 
Tornea would be full fufficient ; but to difcover the 
true ratio of diameters, is what can be performed only 
by the comparifon between the degrees, whofe mutual 
diflance is the greateft. 
Such a ratio once fixed, if it happen to be lefs than 
230 to 231, it will be very eafy, by the preceding 
theory, to imagine fome hypothecs for the infide of 
the 
