2 2o Gen. Roy’s Account of 
had been employed in the North of France, the fame fort of 
refult as we have obtained in Kent would probably have been 
the confequence ; in which cafe it cannot be doubted, that the 
fpherical hypothefis would have been entirely reje&ed, and their 
lengths of degrees of longitude would have been fuited to an 
oblate fpheroid, whofe degrees of the meridian and of great 
circles perpendicular to it had nearly the proportion to each 
other of 60840 to 61239 for the middle latitude between 
Greenwich and Paris, being an excefs of 399 fathoms on each 
degree in the longitudinal dire&ion. 
On the whole, therefore, as matters ftand at prefent, it is 
fufficiently obvious, that, in the total extent of the kingdom of 
France from Strafbourg on the eaft to Ufnant on the weft, the 
difference between the old and new longitude amounts to be- 
tween 1 7 and 20 feconds of time ; that is to fay, the real dif- 
ference between the meridians of thofe places, it is prefumed, 
will not be found by future obfervations made on the occultations 
of the fixed ftars, to be fo great as it was formerly fuppofed to 
be by that quantity, or fomething approaching it very nearly. 
Art. XVI. The obfervations of eclipfes cannot be depended upon 
for determining •with fufficient accuracy the difference of longi- 
tude in vicinal ftuattons. 
/ - ^ m 
Finally* with regard to differences of longitude, it may not 
be improper in this place to remark, that, in vicinal lituations, 
fuch as Greenwich and Paris, the eclipfes of the fun and 
moon and Jupiter’s fatellites do not, in general*, give refults 
* The refult deduced by the ProfelTor Piazzi, of the Univerfity of Palermo, 
from the obfervations of the eclipfe of the fun on the 3d of June, 1788, made 
at Greenwich, in company with Dr. Maskelyne and M. d’Arqjiier, as given 
in the Phil. Tranf. for 1789, p. 58. is an exception well worthy of notice. 
