[ 489 ] 
according to the table in the Elemens d'Aftronomie 
by Mr. Caffini. By taking a mean of both, Florence 
is 44 / <4o // to the Eaft of Greenwich. 
The longitude of St. Peters at Rome is 49 / -54 // 
according to the French Aftronomers. The internal 
contact was obferved to happen at 2i h .09'.36 / '. But 
as it is not faid where this obfervation was made, the 
longitude given above will be found to be fomewhat 
inaccurate. 
Oblervations were alfo made at Madrid and Lifbon; 
at the former, the internal contad happened at 
2o h .6 / .$6" apparent time : and at Lilbon at 
i9 h .44 / .26 // . The longitude of Madrid, as given in 
the Philofophical Tranfadions, is certainly erroneous ; 
being more than a minute and a half too little, if the 
obfervation of [the tranfit can be depended upon. 
At Lifbon, the longitude of the place was not 
determined by Mr. Ciera, who obferved the tranfit, 
when Mr. Pingre, from whom I have taken the ob- 
fervation, left it in his way from Rodrigues. From 
the belt accounts that I can colled, particularly 
from the 385th number of the Philofophical Tranff 
adions, and from an account of fome obfervations 
by Mr. Short, Lifbon is about 36'. 2 6" to the Weft 
of Greenwich. 
Now in order to deduce the Sun’s parallax from 
the obfervations related above, 1 proceeded in the fol- 
lowing manner. Having fubtraded the difference 
of longitude between Greenwich and the Cape 
=i h .i3 / .28 // from 2i h .39 / .52 // the mean of the ob- 
ferved times at the Cape, and compared the remainder 
with the obferved time at Greenwich, I find that the 
internal contad was obferved 24" later at the Cape 
1 than 
