ASTRONOMICAL PAPERS. 



43 



forenoon and afternoon obfervations, we were aflured of 

 the rate of our clock's going and the time of apparent 

 noon to a fingle fecond. We did not think it neceffary 

 to burden our minutes, with the great number of obfer- 

 vations of this kind, that we made. Let us fuffice to 

 fay, that they were made with the utmoft care, and that 

 our time-piece was fixed to a large port funk into the 

 ground four or five feet, fecured from fliaking by a brick 

 wall at the bottom, and no ways communicating with the 



fides of the building. 



The long expected day of the tranfit came, fo favour- 

 able to our wifhes, that there was not the leafl appearance 

 of a cloud in the whole horizon from morning 'till night, 

 and the fky was uncommonly ferene. The committee af- 

 fembled in the morning at the obfcrvatory, examined the 

 adjuftment of their telefcopes anew, and appointed two 

 aififtants to obferve the clock, one to count the feconds 

 with an audible voice, and the other to write down the mi- 

 nutes as they were compleated, to prevent a miftake in 

 that article. 



Every obferver being fixed at his tclefcope, at Icaft half 

 an.hour before the beginning of the tranfit; we obferved 

 the contafts of the limbs of Venus and the Sun at the 

 times mentioned in the following accounts, as they were 

 drawn up feparately by the obfervers themfelvcs, and are 

 here inferted in their own words. 



Account of the Co^TAcrSy by JOSEPH SHIPPEN, Esq^, 



" I obferved this very uncommon and curious phoeno- 

 menon with a new refleding telefcope, made by Mr. 

 George Adams, whofe tube is two feet and half an inch 

 long, its aperture 4,15 Inches diameter, and its magnify- 

 ing power about 90 times. After having well adjufted 

 its focal diftance, the Sun's limb appeared fo well defined, 

 that the leaft obfcuration of it might be clearly difcerned 



by a good eye, 



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