w 



4.Q 



A ST R O N O M I C A I, P APE R S. 



1 he committee having defired me to ufe the large re 

 fleaor mentioned above, I chofc that power which man-ni- 

 les the diameters of objeds 300 times; with which l"ob- 

 iervcd at 2\ 13'. 48". apparent time, an obfcuration on 

 the north-eaftern limb of the Sun, gradually adv^nchm 

 iorwards with a tremulous mbtion, which, from its irre- 

 gular and duikj appearance, I conckided was occafioncd 

 by^he refradion on the Sun's rays ihrongli tlie atmofphcrc 



" J»ch atmofphcre foon afterwards became very 



w 



of\'enuc,, 

 oI)fervable to us all. 



From tl)is 1 was led to conclude that 



c 



tae contad did not happen till about i j or 16 feconds af- 

 terwards, when there ^vas n large and evident imprcffion , 

 made on the limb of the Sun; but as the precife moment 

 ot the external contad cannot be noted by an obfcrver, the 



body 



o. Venus not yet being intcrpofed between the Sun's 

 hmb and the eye; this coatad muft have happened about the 

 time that her atmofphere made tlic abovementioned obfcu- 

 ration, and thereforelam of opinion that the true timeof the 

 contad Ihould be accounted at 2". 13'. 48", or it may be 3 

 or 4 feconds fooncr, when nothing but the atmofphere of 



Venus, which preceded her body, appeared on the limb of 

 the Sun. About the time that the center of Venus ap^iroach- 

 ed the Sun's difk, I faw the whole body of Venus, hercaftern 

 edge being furrounded with a faint light which was doubtlefs 

 occafioned by her atmofphere refrading the Sun's rays. 

 At 2\ 29' . 1 1 " mean time, or 2\ 3 1 ^ 26" apparent time, I 

 law the mternal contad, when the whole body of Venus 

 was u.L:oduced within the difk of the Sun, and the thread 

 of light had compleatly furrounded her, although not as 

 bright as It became in two feconds afterwards. 



From what has been faid, it appears that the apparent 

 times of the contads may be reprefcnted at one view in the 

 following table, as they were noted by the different obfervers. 



ift T^xcter. Contad^. 

 h. m. fee. 

 a. 13. 47 Ap- T. 



2. 13. 46 



a. 13- 50 



/>r. IVillia/nfotiy 

 Mr. Pcarfon, 

 Mr. Thoni^fon^ 

 Mr. Prior'. 



\U>:' 



A well-flcfincdbLick 



dentin Q's limb, at^ 



Vol. L 



a. 13. 41 

 a. 13. 48 



a. 14. _3 



ift Inter. Contata, 

 h. m, fee. 



2. 31. 34 Ap.T. 



2. 31- 35 to 27 



3. SI- ^6 to 305 



a. 31. a8 



a. 31- ^6 



MagnifyJHjT 



Powers, 

 So times. 

 90 times. 



Co times. 



100 times. 

 300 times. 



G 



After 



