Y-.C ^ 



'^if^n 



M 



PAPER S 



33 



10 minutes, 



intervals between them muchfhorter than 8 or lo mmutes 

 they would have been of little ufe in the proied^n an i 

 would have crouded it too n.uch. Nor coufd we hav^ be- 

 tter nt r -r '" 'fr' '^ '"^^^""^-^' ^^^^^o^ 



the vern e. , &c. f a much larger number had been taken 

 In order to judge of the errorof the micrometer f,f am ) 

 Jupiter'3 diameter was not only taken with it bo h lays 

 V.Z to the right and to the left, but Mr. Rittenho L Til e ' 

 w,fe took .nuan to the right of ro diameters of a wh e~ 



m nlt'^lh 'lt"''ff ° yards diftant, and alfo a „.an of 

 many to the left I his work was performed early in tlie 

 morning before fun-rife; when the air was free fmm 1 

 tremulous motion; and the refult gave an error of alf 



ment of i 



meafures. 



1 2 to be fubftraaed from all th 



e micrometer 



It was onee intended ftill further to confirm the work 



of tt a".nuTr"^':^r''r ' l^ ^PP'>^'"g ^'- obfervation 

 ot the appulfes of the hmbs of the Sun and center of Fatus 



mentioned to have been taken above. But the lines necef- 



fary for this would have confufed the figure; and the 



rofTe^he Tb"" '""?^""^^ ^'^^^^'^' -yfurthe 



ult ot the others, than to try how well they would agree 

 was thought to be needlefs,efpecially as the fradions of £ 



the ac ;? '''"/r" ""^ ""' ^^^"^^ '^^' '- - 'o com upTo 



Lol rdo7n.^'^'^ "^™^^^^- ''' ''''' -^-^' ^h^/are 



Dr/ineation ofthcTranJlt of Venus over the Sun, accordin<r 

 to the foregoing Ohjerimtwns, ^ith the principles of the 



By Mr. Rittenhouse, 



HE Sun's horizontal parallax is affumed 8^6c 

 .^ at his mean diftancefrom the cwfh- -T..^^ i • !' 

 ai.d theobfcrved leaft diftanceof the cent ^of 1 e's^^^^^^ 

 Venus the chord of the tranfit line was laid down "rhe 

 J^un s femidiameter and that of Venus are taken as by the 



aj by the hrft m icrometer diftance of the limbs at ' 



vol. T. n 



3 -7' 19'' 

 apparent 



