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198 
numbers of stars obtained is below the average of the year. 
Lastly, were he to select December as the month producing 
the greatest number of hours dark enough for his purpose, he 
would again be foiled, the number of stars obtained per hour 
of darkness in this month being considerably below the average 
of the year. It will be perceived that September has proved 
to be the most productive absolutely, although three other 
months stand higher in horary results. At this season there 
is little to contend with, excepting clouds. The nights are long 
enough for the strength of the observer, and there is no frost 
to coat the object-glass. The latter is a serious obstacle in the 
colder months, and especially in this Observatory, where the 
large equatorial is completely exposed ; and the object-glass 
too heavy to be frequently removed with prudence. 
‘‘Tn my general examination of the zones, planets were sought 
for, but only two detected :—Neptune, in vol. 1., page 196, in 
right ascension, 22" 27" 26°; and Melpomene, in vol. u1., 
page 177, in right ascension, 8" 6" 34°. The paucity of ob- 
servations of planets found in the zones may be thus accounted 
for. The telescope is almost invariably used near the meridian, 
and, the time of a planet’s passage being known, the zone-ob- 
serving was frequently abandoned to obtain the most accurate 
place of the planet with the meridian circle. Facts indicative 
of an unknown planet were always noted in forming the cata- 
logue, and many places have been subsequently examined with 
the meridian circle. Hitherto the only results have been notes 
of two or three missing stars, on which we cannot at this mo- 
ment lay our hands. A comparison by Mr. Graham ofa por- 
tion of his maps, in course of execution, with the heavens, gave 
_ the following stars as missing :— 
Vol. 15 page 73, ..°'. (4° 18" 248 
“ip LOO, > car 201848 
i Sy etbiay si ape Oo . ae 
- “AR hdr Pome te aarti ie 
Vol. 115 page: (8,4 a. 4 Ba 
Sie gh MUR 4 ea eee 
