hJ-' 



104 



MATHEMATICAL a nb 





lefs than it flaould have been, from the obfervations made, 

 with the like inftrument, at the tranfit of Venus, in 1 761, 



Mr 



Mr Mafon 



•when the Sun was at a confiderable aUitude; and moft 

 likely the Sun^s diameter was enlarged in proportion, 

 though it might have been difficult to have afccrtained it 

 by adual meafure, had time allowed me to make the ex- 

 periment with the fame micrometer before the Sun entered 

 into a black cloud near the horizon. 



Six other perfons alfo obferved the contacts of Venus 

 here, and noted fome other phoenomena. Their names 



are, 



Mai 



ac- 



> 



quainted with aflronomy and allronomical calculations 

 who has made and examined many belonging to the nau- 

 tical almanac, and has been fo obliging as to come here 

 and aflift me in making aftronomical obfervations, during 



Mr. Will 



who is 



gone to the North Cape, by appointment of the Royal 

 Society, to obferve the tranfit of Venus there. The others 

 arc, the Rev. Wiljiam Hirft, who obferved the former 

 tranfit of Venusi in 1761, at Madras; John Horfley, 

 Efq. a gentleman whom I had the pleafure of firft com- 

 mencing an acquaintance with during my voyage from St. 

 Helena to England, in the Warwick Eaft-India fhip, and 

 who then, and in feveral voyages fmce to the Eaft-Indies 

 and home again, obferved and calculated the longitude 



from diflances of the Moon from the Sun and fixed ftars 

 with the greateft accuracy; Mr. Samuel Dunn, who has 



had a good deal of pradice in making aftronomical obfer- 

 vations, and who carefully obferved the former tranfit of 

 Venus, ini76i, at Chelfea; Mr. Peter Dollond, whofe 

 great {kill in conftruding achromatic and refleding tele- 

 fcopes; and Mr. Edward Nairne, whofe {kill likewife in 

 the fame way, and in making all kinds of mathematical 

 and philofophical inftruments, are fufficiently known to 



the public. 



Mr; 



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