[ 2 73 3 
made at both ends of the meridian, with the limb of 
the fedtor turned both eaft and weft at each extre- 
mity ; this meafure of a degree feems to me to be as 
well ftated, and as much to be depended on, as any 
that has been made ; and will, I prefume, be thought 
a valuable addition to the other meafures of degrees, 
which have been taken with great care and pains, by 
various learned men, particularly the members of the 
Royal Academy of Sciences at Paris, who have ac- 
quired fo much juft reputation by their valuable la- 
bours beftowed on this fubjedt. 
It may not be improper to remark, that the level 
difpofition of the country this degree paffes through, 
which, as I underftand, alfo obtains further to the 
fouth, and, in a great meafure, to the north of the 
limits of the fame, gives fome advantage to this mea- 
fure, with refpedt to the ufe that may be made of it 
in inquiring into the figure of the earth ; as there is 
no room for fufpicion that the plumb-line of the fec- 
or could be defledted materially from its proper poli- 
tion by the attraction of any mountain, or even ele- 
vated ground of a more moderate height, continued 
for a great length ; which latter circumftance, not 
taken notice of before, the learned Father Bofcovich 
has fhewn, may produce a very confiderable devia- 
tion of the plumb-line, in the elaborate treadle of the 
meafure of a degree of the meridian between Rome 
and Rimini, taken by himfelf and his learned co- 
adjutor, Father Le Maire. 
N n XLII. Ob - 
Vol. LVIII. 
