[ i9 1 
Caftttis , Clair aut the Son, and Monnier the Son, who 
have been fent to the North, they departed from 
France in April of laft Year 175 6, with Mr. CelJiUs , 
Profeflbr of Aftronomy at Upfal , who accompanied 
them to Sweden , as far as the Bottom of the Gulph of 
Bothnia , where they might meafure about a Degree 
on the Meridian at its croffingthe Polar Circle. But as, 
by the laft News I received from them, they had not 
finifffd their Operations, *tis not yet known whether 
the Magnitude of the Degree meafured bjthem, fa- 
vours the Opinion of M. CaJJini , or that of Sir Ifaac 
Newton . All we know is, that they have found the 
length of the fimple Pendulum favourable to the 
latter, that is, longer under the Polar Circle than far- 
ther South. 'My Brother *De laCroyere , had already 
found the fame Thing: For being at Archangel in 
1728, he there obferved, in the rtioft exaft Manner 
he poflibly could, the Length of the fimple Pendulum, 
which he found to be Parts of a Line longer than 
at 5 Paris, 
We are likewife informed hy the other Aftrono- 
merS’ gone to Feru, that in their Way towards the 
Equator, being at St . ^Domingo, in the Latitude of 
18 Degrees 37 Minutes, they there found the Pendu- 
lum Twinging Seconds, to be about two Lines Ihorter 
than at ‘Paris.. Thus, all we as yet know from thofe 
Gentlemen, on the Expeditions to the North and the 
Line, confirms the Opinion of Sir Ifaaz Newton 
and his Adherents : And yet M. Mairan , whom I 
have already mentioned, pretends, that this fhorten- 
ing of the Pendulum in. drawing nearer the Equator, 
is in one Seiife entirely independent of the Earth's 
Figure. 
Tim 
