[ "9 ] 
XVI. Propofal of a Method for meafuring 
Degrees of Longitude upon Parallels of 
the /Equator , by J. Michel], B. D.F. R< S. 
Read May 8,r|"1HERE have been already feveral 
| attempts made towards difeovering 
the figure of the earth, by meafuring the length of a 
degree of the meridian in different latitudes : now if 
thefe meafures had been diffidently accurate and 
numerous, and we could alfo depend upon the uni- 
formity of the earth’s furface, we might then immedi- 
ately difeover from them the form fought ; but thefe 
meafures, not agreing exactly to any certain rule, 
leave us dill in fome degree at a lofs. It is therefore 
much to be wifhed, that more meafurements of 
degrees upon the meridian were to be made, in order 
to determine with greater accuracy a quedion of this 
importance. 
But what would tend yet more to determine this mat- 
ter, would be the meafurementof degrees of longitude, 
as well as thofe of latitude. Adronomers have indeed 
expreffed their wifhes that this might be done ; and 
though no attempt has been hitherto made towards it, 
yet as it is probable, that fuch meafurements may fome 
time or other take place, it will not be amifs to fugged 
a method, which will admit of more exadtnefs than 
any I have feen propofed for this purpofe, all of which, . 
depending upon an obfervation of the time, are there- 
fore liable to an error of fifteen feconds of a degree for 
every fecond of time; but the method, I mean to re- 
commend, dands upon the fame foundation with the 
i meafure- 
