On the /ale Lunar Occullal'fon oj Jupilcr. 435 



Apparent time of Geocentric conjunction at Gieenwidi, Octo- 

 ber \S^ 5'' IS"" 14^-5. 

 Longitude of the moon and Jupiter . . 344** 7' l"-39 

 Latitude of the moon south, decreasing . . 46 11-44 



^Geocentric latitude of Jupiter 1 29 42'08 



Horary motion of the moon in longitude .. 36 56'80 

 Horary motion of Jupiter, retrograde . .,0 10-00 

 Horarv motion of the moon in latitude^ .. q o^ '^o 



towards the north pole .. .. J " ^^ 



Moon's equatorial horizontal parallax . . 60 3003 



Moon's horizontal semidiameter „. .. 16 29' 17 



Semidiameter of Jupiter by observation .,0 7*25 

 Sun's HI. at noon per Nautical Almanac 13'' 32 423 



Daily increase 3 45'6 



Equation time at conjunction .-14 4S-6 



The resulting times for Aberdeen are, in mean time, 

 Visiijle conjunction .. .. October 18'' 4'^ 52"^' 2S''7 



Last external contact .. .. 4 58 6*8 



Proportion of Jupiter's diameter immersed 1 5-54 



at greatest obscuration j 14^50 



At Aberdeen the beginning of the occultation could not be 

 observed for clouds. About 5'' 0^' mean time, the Moon and 

 Jupiter were seen for an instant very indistinctly. Jupiter ap- 

 peared a little to the south of the moon's vertex, and nearly one- 

 third of bis diameter was judged to be obscured. At 5'' V 30" 

 the moon emerged from the cloud, but a heavy shower of rain 

 was falling at the place of observation. The externa] contact 

 of the limbs at the end was determined to be at 5"' 1' 58". But 

 the apparent relative path of Jupiter was, for a short time, so 

 nearly in coincidence with the moon's circumference, that the 

 bodies separated very slowly. Owing to this, and to the unfa- 

 vourable state of the atmosphere, the aljove time is perhaps sub- 

 ject to an error of about 5". The telescope used was 3^ feet 

 achromatic by Dollond, with a power of 70. 



By comparing the above results of calculation with observa- 

 tion, it appears that the error of the tables of Jupiter in latitude 

 is nothing; the error in longitude, about 2' 23 " + or too far 

 forward. But as no observation of the time of the moon's pass- 

 ing the meridian cou'd be made, whether this difference arises 

 solely from the error of the tables of Jupiter, or partly from 

 those of the moon, could not be determined. 



I am sorry so few observations liave appeared respecting the 

 late solar eclipse ; one in yoiu Magazine, by Mr. Bevan^ ap- 

 peared to me to have been most carefully made; and 1 make no 

 doubt but the instants of beginning and end were observed 



•^ J '^ within 



