[ ’9 ] 
I fhall not enter here upon a detail of the immenfe 
Labours of modern Mathematicians on this Head, as 
thofe of Feme l in France $ of Snellius , Blaeii , and 
Muffchenbroek in Holland $ Norwood in England j 
Father Riccioli , and lately Monfignor Bianchifii in 
Italy j and the Gentlemen of the Academy of Sci- 
ences in France 5 to get only the precife Magnitude of 
a Degree in the Meafures of their refpe&ive Coun- 
tries. But I will anfwer an Obje&ion which might 
be raifed hereon, viz. That it was needlefs to under- 
take thefe fame Operations in fomany different Places, 
fince the Magnitude of a Degree once determined in 
the Meafures of any one Country, may be eafily re- 
duced to the Meafures of any other, by the exaft 
Knowledge we now have of the Proportions of mo r 
dern Meafures. Whence it might be inferred, that 
after all the Exaftnefs which the Aftronomers of the 
Royal Academy of Sciences of Baris have detain'd 
by their Labours, in drawing their Meridian from otic 
'Sea to the other, it is unneceffary to enter upon a new 
'Undertaking of the fame Thing any where, elfe-: 
fince, in order to reap the Advantage of that Work 
for the Geography of each particular Country, no- 
thing more is requifite than exaftly to compare the 
Meafures of thofe Countries, with thofe made ufe erf 
'by the French Aftronomers in their Operations and 
Calculations. 
Now, taking Rujfia for the Example, thc-Gcogra- 
phical Meafures of which are Werfts, divided each into; 
500 Sagenes , and each Sagene fuppofed to be exadly 
feven Feet Englifh 5 this Relation once known, .as alfo 
the exa£t Relation of <the Englifh 'to the French Foot, 
iOr to the Toife of fc Feet, which the French Aftro- 
nomer# 
