564 PHILOSOPHICAL TRANSACTIONS. [aNNO 1761. 



XL II I. The Observations made on the same Transit at Upsal in Sweden. By 

 Mr. Torhem Bergman of Upsal. From the Latin, p. 227. 



The first appulse to the sun's border could not be observed; at 3** 21™, in the 

 morning, when first seen, the transit had commenced. The first internal con- 

 tact, or the complete immersion, was at 3** 37*" 43^ At the exit the internal 

 contact was at Q** 28™ Q*, and the external contact, or end of the transit, was at 

 ^ aQ^ 30'. The observed diameter of Venus between 57" and 58". 



On this occasion the observers thought they perceived symptoms of the atmo- 

 sphere of Venus; viz. because when the planet was partly on the sun only, the 

 extremity of the exterior part was faintly illuminated and visible ; also, on the 

 edge of the planet quitting or approaching the sun's border, something like a 

 drop of fluid seemed to connect them for some time. 



XLIF. An Account of the Observations made on the Transit of Venus over the 

 Sun, June 6, 1761, at Cajaneburg in Sweden. By Mons. Planman. Trans- 

 latedfrom the French, p. 231. 



Some new observations have shown that the difference of meridians between 

 Stockholm and Cajanebourg is only 38' 40" to a5", that is, half a minute less 

 than he before thought it. This correction has convinced Mr. Planman, that in 

 his observation on the interior contact of the limbs of Venus and the sun, at that 

 place, there has happened an error of a minute ; not through the fault of the 

 obsen^er, but that of his assistant, who counted the seconds at the clock : so 

 that instead of lO** 8™ 58*, it should be 10*" 7"" 58». Mr. Wargentin thinks it ex- 

 tremely probable, that this is the fact ; for on this correction all the observations 

 of Mr. Planman agree very well with each other, and with those of the other 

 astronomers. 



XLV. A Second Account of the Transit of Venus over the Sun, June 6, 1761. 



By the Rev. Nathanael Bliss, M. A., Savilian Professor of Geometry in the 



University of Oxford, and F. R. S. p. 232. 



The interior conjunctions of the planets Mercury and Venus, that happened 

 near the ecliptic limits, have always engaged the attention of astronomers, as 

 they furnish the best means of detennining some of the most important elements 

 in the theory of those planets. The transits of the former have been often and 

 carefully observed by the most eminent astronomers, ever since the invention of 

 the telescope; and it may be presumed that the elements of Mercury's theory are 

 established as accurately as can be expected. The opportunities of observing 

 Venus on the sun's disk occur so seldom, that the astronomers of these days 

 have reason to think themselves peculiarly happy in being eye-witnesses of so rare 



