^\ in DSOM OBSER1 um;i 



• IMBR1DGE \NH HUDSON. 



mmon'S riR8T LIMB 



Mean of twenty-nine determinations from moon's jliral limb, 5A. 26m. 32 v. 



Probable error, ± ls.O. 



Mean difli I 8 B 



1839, August 2, 

 25, 



I3m.51*.18 



1 1 55 . 1 1 



UOOH'a SI c OJfb LIMB 



October 24 



5/i.25m.62s.i 

 62 .8 



1 r.„l. 30 i I.'.;/,. 0:i.,. !l 



November 22,1 15 64 .44 



Meanoffour determinations from moon's second limb, 5/i. 26m. Is. 7. Mean difference ±1 ■>■.'.•. Prol fcO.8 



Mean of thirty-three determinations from both limbs, allowing double weight to the first limb, 5A.26m.2 ' 

 Longitude of Cambridge, — 23s. 5. Longitude of Hudson, from Greenwich, 5A. 25m, 89».2. 



OXFORD AND 111 DSON. 

 MOON'S F/RST LIMB, 



Mean ofl3 determinations from moon'syirsi limb, 5//. 20»/i. 32*. 7. Mean different bteanor&ll.4 



MOl '\'s -; , OtfD 1.1 M it 



1840, July 15,' 11m. 17s. 68 



August 14, 10 42 .12 



October 12, | 13 42 .08 



Meanof 5 determinations from moon's second limb, 5/i.20)/i. (8 5 Mean difference, ±4 B I' 



Mean of eighteen determinations from both limbs, 5/i. 20m. 36s. 3. 



Longitude of Oxford, -f- 5m. Is. 5. Longitude of Hudson, from Greenwich, ttA. Mm 81 B 



» The correction for defective illumination of the moon'l firM limb 1 — mooted from the formula, 



moon's radius x versed sine of'/; where 6 is tin- difference of A. U. of the sun and moon, rHmtnteh t n ' 



and multiplied by the cosine of the sun's declination. 



\ "L. X. — 3 



