562 PHILOSOPHICAL TRANSCATIONS. [aNNO I76I. 



In comparing these observations together, you will perceive that they do not 

 agree so near as was hoped for ; and those which were made at Paris agree but 

 little better. 



XL. Observations of Venus on the Sun, made at Paris, June 6, 1761. By 

 Jerome Lalande. From the Latin, p. 21 6. 

 Clouds in the east obscured the sun from *A till 7 o'clock, at one interval be- 

 tween which, he took some observations of the limbs of the sun and Venus at 

 the vertical wire of the telescope, whence he concluded that the longitude of 

 Venus, freed of parallax, was 2' 35" west of the sun's centre, and the latitude of 

 Venus 9' 58"; viz. at S*" SI*" 46*. After many other observations of the same 

 kind, as well as of the distances of Venus from the sun's limb, Mr. L. at the 

 planet's quitting the sun's disk, observed the internal contact at 8'' 28*" 25*, and 

 the external at 8*" 46"^ 54*, apparent or true time. Hence he infers, that the 

 apparent time of the conjunction was 5 52*", the planet's latitude 9' 30", tlie 

 longitude of the node being 8* 14° 32' 20". 



XLL An Account of the Observations on the same Transit made in and near 

 Paris. In a Letter from Mr. Benedict Fernery Professor of Astronomy at 

 Upsal, and F. R. S. From the French, p. 221. 



Messrs. Maraldi, De la Lande, De Lisle, and Messier, remained in town, at 

 the Royal Observatory in the Luxembourg palace, and at the Hotel de Clugny ; 

 Messrs. de la Caille, Le Monnier, De Fouchy, and Ferner, went out to Con- 

 flans, St. Hubert, and to the Chateau de la Muette, where the King's philoso- 

 phical and optical chamber is. It was in this last place, which is situated 144-'' 

 of time to the west of the Royal Observatory, that Mr. F. made his observations, 

 in company with Mons. de Fouchy. 



To take the distances of Venus from the limbs of the sun, for want of a good 

 micrometer. Mr. F. made use of a quadrant of 24 feet ; and for obser\'ing the 

 egress, he had a good reflecting telescope of 28 inches focus and 5 inches aper- 

 ture, which magnified about 80 times. Having calculated and reduced his ob- 

 servations to the Royal Observatory at Paris, he found that the western limb of 

 Venus toudied the western limb of the sun, or that the luminous thread of the 

 sun was broke by her, 



At 8^ ^8*" 29^* True time, morn. 



Last contact, at 8 46 43 



i Conjunction of with 9 . . 5 52 20 



Southern latitude of O 9 32 



Longitude of ^ being . 2» U** 32' 23^ 

 During the whole time of observing with the telescope, he perceived a light 



