rOL. XIH.] PHILOSOPHICAL TRANSACTIONS. ()43 



With the Sextant again. 



May 9, 10** 20" .... Jupiter from B in IT)^ 38 



23 .... repeated 38 



26 .... Saturn from the same star 38 



28 .... repeated 38 



1 J , 9 28 ... . between their centres 



31 .... repeated 



16, 9 22 ... . between their centres — dubious 



From these observations I state the distances of the planets from the fixed 

 stars May 7, at 9h. 5 m. P. M. as follows : 



Saturn from the Lion's heart , 10 



Jupiter from the same 10 



Saturn from E in the Lion's head 8 



Jupiter from the same 8 



Hence the true longitude of Saturn ^ 14° 27' 41''; lat. 1° 12' 4&' north 



of Jupiter ^. ... 14 26 37 ; lat. O 56 43 north 

 Difference of longitude 1 4 ; lat. O 1 6 3 



The difference of latitudes something exceeds the distance measured with the 

 micrometer, by reason that the wind then shaking the sextant permitted us not 

 to be so exact as usual, but the difference, being less than half a minute, I 

 esteem inconsiderable. 



The diurnal motion of Jupiter from Saturn was now 3' 15''. Therefore as 

 3' 15", one day's motion, is to one day or 24 hours, so l' 4" the distance of 

 Jupiter from the c5 with Saturn, to 8 hours; the interval between the observa- 

 tion and following conjunction, which was therefore I7h. after noon, or accord- 

 ing to the vulgar reckoning, May the 8th, at five o'clock in the morning. At 

 which time the true place of the planets is SI 14° 28^', the difference of their 

 latitudes 1 5' 40", Saturn being so much more northerly than Jupiter. 



In all the best esteemed astronomical tables extant, the mean motions of the 

 planet Saturn are too swift, of Jupiter too slow, considerably ; hence it came to 

 pass that they made the direct conjunctions some days later, the retrograde 

 earlier, than they were found by observation. 



Traite de VOrgane de VOuie, par Mom. Du Verney, 8vo. ^ Paris, l683. 



N° 149, p. 259. 



This work is divided into 3 parts, the first of which contains an anatomical 

 description of the organ of hearing. • The 2nd the use of all the parts of that 

 organ, grounded on the mechanism of the whole. The 3d and last, the dis- 



4n 2 



