ASTRONOMICAL PAPERS. 



2 1 



OBSERVATIONS of th& ZmHh Dlfiance of the Suns upper and lower Llmh ; and the latitude of 



the Ohfervatory diductdfrom each pparatcly 



0's upper limb a Zenith. 

 May aj. 1 8^ 48'. 45' 



a6. 18. 



27. 18; 



^une I. 17. 



ft. 17. 



4. 1 7- 



doukfuL 6, 17.. 



7. 1.7. 



13. 16. 



38. 



a8. 



i3 



21 



43- 



47 



36. 



16 



21. 



51 



8. 



53 



3- 



ai 



41. 



la 



37. 



45 



Hence Lat. 

 40^. 10'. 17" 

 40. 10. 10 

 40. 10: 10 



cloudy, and 

 doubtful. 

 40. 10. X 



40. 9. 5a 



40. 9. 34 



40, 9. 47 



40. 10. 14 



40. 10- 8 



O's lower limb « Zenith. 

 June 



8. 



10. 

 II'. 



I4f 



17^. 29'. 33 



17. 

 17. 



17. 



24- 



20. 



15- 

 6. 



35 



5" 



59 



9 



Hence L?.t. 



40^ 9.' 48" 



40- 9- 47 



40. 9- 49 



40. 9. 5» 



40. 9. 58 



Mean of the above 1 

 f} obfervations of Q'sJ- 40 

 upper limb ii J- 



Do. from the 5 ob- 

 servations of lower 

 limb, 



Mean of both,., 

 And 



10'. 1". 33 



f!f 



Mean of the 5 oUO 

 fervations of the low- J- 40^. 9'. 50". 4 8^' 

 ,.er limb,, 



/ 



S 



40.. 9. 50. 48' 



40''. 9/ 56'' low 

 39- 56. 54 



for the lat. of Norrihn Obfervatory. 

 lat. of Philadelphia Obfcrvatory. 



The difFerence of the above obfervations Is greaterthan 



might be wifhed. AH that can be offered to excufe them 



is the want of better inftruments; though Mr. Rittenhoufe 



thinks the differences chiefly arofe from the adion of the 



fun on the wooden frame which fupported the quadrant*^ 

 For he always obferved that when the fhutter in the roof 

 was opened, the plummet-wire would, in a minute or two, 



leave the point, though it had flood over it quietly all the 

 forenoon. Yet, not withftanding thofe differences, a MeaUf 

 from fo many, maybe fuppofed very near the truth; fince,, 

 if we leave out that of June 6th, which differs moft 



from the others, the mean of the reft v^^illbe but 2" great- 

 er than it is fet down above. 



So far I have given y[v.'Rittenhotife% obfervations, pre- 

 vious, and fubfequent to the Tranfit^ for afcertaining the 

 going of his timepiece and fixing the latitude and lon-^ 

 gitudeof the obfervatory, from February 15th to July 8th;; 

 by which it will appear what laudable diligence he hatb 

 ufed in thefe material articles. He hath taken many more 

 obfervations fmce; but thofe given above, are judged fully 

 fufficient to ilicw that both the latitude and longitude of 

 the obfervatory may be'^ depended on, and alfo the times 

 given on the day of the tranfit.^ It 



* Aathc mcnfurallon of the ground between the Ohfermatcries of Philadelphia and Norrlton,, 

 will give the fame di/Tercnce both of longitude and latitude, which was got by the different 

 agronomical ulfervations at each place, they may be therefore taken as ft confirm.ition of each 

 •thers. 



