C 356 ] 
Venus’s exterior limb. Neverthelefs, I would not 
hence infer, that obfervations made by adronomers in 
didant places fliould agree together within fuch nar- 
row limits ; for I know they will not even in the 
fame place, and that a difference in the fkill or 
judgment of the obfervers, in the telefcopes, and 
perhaps in feme other little circumdances, not eadly 
didinguifhed, may produce much greater difagree- 
ments, efpecially if the Sun be low, as it was here ; 
in like manner as in obferving the eclipfes of Jupiter’s 
fatellites, the immerfion or emerlion fliall often feem 
indantaneous, or nearly fo, equally to two obfervers in 
didant places, and yet the abfolute timesof the obferva- 
tions may differ a minute of time or more from each 
other, owing to the difference of telefcopes, weather, or 
other circumdances. Indeed, in the prefent cafe, the 
limit of differences is certainly much narrower} but 
what it is I fhall not at prefent venture to fugged, as 
that may better be done when all the obfervations 
that fhall have been made of the tranfit are colledfed 
together. The telefcope which I ufed was an ex- 
cellent refledting one of two feet focus, made by the 
late ingenious Mr. Short, and is the fame with which 
the lad tranfit was obferved here by Mr. Charles 
Green. I applied the magnifying power of 140 
times, and ufed fmoaked glades to defend the fight, 
which are much preferable to black or red glades, 
as diewing the objedts more didindt, and being much 
more pleafant to the eye. 
I fhall now endeavour to deferibe, as accurately as 
I can, fome other phaenomena which I noted during 
the immerfion of Venus, and to mention fome others, 
which by fome ingenious perfons were expedled to 
have 
