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XVII. A Letter from Monfeur Wargentin, 
Secretary to the Royal Acade7ny of Sciences 
m Sweden, to Mr. John Ellicott, F.R.S . 
relating to the late Lranft of Venus. 
Stockholm, December 24, 1762. 
Read March 17, 
1763 
T 
HE obfervations upon the lad 
tranfit of Venus over the Sun 
made at the Cape of Good Hope are excellent, and 
feem to decide, that the horizontal parallax of the 
Sun is 8" 1 or 8", 3 at mod. I had before found 
it to be that quantity, from the obfervations made 
in Europe compared together; but the oofervations 
made at the Cape confirm it with the greated evi- 
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It is of importance to be affured of the longitude 
of the places where the obfervations were made. I 
have endeavoured to determine them the bed I was 
able by obfervations of the eclipfes of Jupiter s fatel- 
lites, made at the fame places. That you may the 
better judge, I thought proper to fend you all the 
obfervations of thefe fatellites made at different places 
the lad year. I defire you would communicate them 
to Mr. Mafon, and all thofe who intered themfelves 
in the* refearch of the parallax. It is pity that mef- 
fieurs L’Abbe Chappe, and Rumoffi, did not fuc- 
ceed in obferving feveral eclipfes of the fatellites, at 
Tobiedce and Selenginfk, the better to confirm the 
Longitudes of thofe places. However it appears to 
me, that the difference between the meridians of 
K 2 Green- 
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