( 2« 7 ) 
Surface of the Earth muft be deprefs’d towards G, and 
rife farther from the Axis towards I, in order to become 
perpendicular (that is, to have its Tangent perpendicular) 
to the Line L /, in which we have fhewn that the 
Plumb Line muft defcend. 
If there is any Body foTond of Monfieur Caffini ’s 
Hypothecs, as to deny the Diurnal Motion of the 
Earth for the fake of it, I hope they will be convinc’d, 
when I fhew the Meafures, upon which it is founded, to 
be inefficient for determining the different Lengths of 
the Degrees of a Terreftrial Meridian. 
But here I would not be thought to endeavour to 
leften the Praife due to the Gentlemen of the Royal 
Academy, for carrying on a Meridian the whole Length 
of France , from \ Dunkerque thro’ the Royal Obfer- 
vatory at Tarts, quite to the Tyre naan Mountains 
on the Borders of Spain, Aftronomy and Geography 
are doubtlefs much indebted to the Encouragement 
given by the French Government, and to the Care of 
their Mathematicians, who have omitted no proper 
Method for drawingtheir Meridian, and correcting it as 
they went on. So many Obfervations of the rifing and 
fetting Sun, fo many equal Altitudes of the fame Stars 
accurately taken, fo many Digreffions of Stars, fo many ' 
other Obfervations made with the Telefcope and good 
Pendulum- Clocks — all compar’d together, for the true 
fettling of the dired Way of this famous Meridian, leave 
no Doubt but that it is as perfect as the Nature of the 
Thing, is capable of. And, certainly, by the Help of 
this Line, and the feveral Triangles made ufe of for 
carrying it on, a better Map of France is made, 
than has ever been of any Country before : Nay, be- 
lides, I believe we may, at a Medium, very well re- 
ceive their Number of 5*7060, or 5*7061 Toifes, for 
the Meafure of a Degree of 3 Meridian of the Earth, 
one 
