ASTRONOMICAL OBSERVATIONS 



III. OBSERVED OCCULTATIONS OF FIXED STARS AT HUDSON OBSERVATORY. 



No. 



1841, June 2 



1842, June 20 



rt Scorpii 

 a Scorpii 



Immersion. 

 Sidereal Time. 



Emersion. 

 Sidereal Time. 



12A.43m.28s.32 14//. 

 12 57 17 .82 13 ! 



lm.2Us.90 Im. pretty good obs.; Em. tolerable obs. 

 i2 16 ,8911m. and Em. both good. 



IV. LONGITUDE OF HUDSON OBSERVATORY. 

 Havinc obtained a few corresponding observations of the moon from European obser- 

 vatories, I have derived some determinations of my longitude. The results are exhibited 

 in the following tables. 



GREENWICH AND HUDSON. 



MOON'S FIRST LIMB. 



Vlean ol' fifty-three determinations from moon's first limb, 5/t. 25m. 39s. 9. 

 Probable error, ± Os.65, 



Mean difference, ± 5s. 6. 



MOON'3 SECOND LIMB. 



Mean of nineteen determinations from moon's second limb, 5/t. 25m. 42s. 0. Mean difference ± 4s.7. 

 Probable error, ± 0.92. 



Me: i seventy-two determinations from both limbs, allowing double weight to the observations of the first 



limb, '.ih. 25m. 10s. 6. 



