Trial of the Meridian Circle, &c. 45 
vy Pegasi 2% +0,021 a! Libree alte 40,032 
a Arietis .. +0,036 a? -. +0,055 
a Ceti -. —0,042 a Corone .. +0,081 
a Tauri -. +0,131 a Serpentis .. +0,074 
a Aurige .. +4,137 a Scorpii .. —0,105 
8B Orionis .. +0,119 a Hereulis .. +0,128 
6 Tauri -- +0,161 a Ophiuchi ... +0,183 
a Orionis ., +0,213 a Lyre ~~ +0,137 
a CanisMaj. +0,113 y Aquile .. +0,104 
a Gemin. .. +0,206 a -» +0,088 
@ Canis Min. +0,196 -.» +0,062 
B.Gemin, “..' +-0;146 «' Capricorni .+0,014 
a Hydre .. +0,257 ae -- —0,042 
a Leonis .. +0,214 a Cygni -. +0,116 
B — 2s. +-0,158 a Aquarii .. +0,028 
B.Virginis .. +0,123 a Piscis Aust. —0,142 
a -» +0,073 a Pegasi -- +0,047 
a Bootis .. +0,137 a Andromede +0,090 
The mean of these differences is +0’,095; being about the 
quantity by which Mr. Pond’s right ascensions, in the whole, 
exceed mine. You will remember that the observations, made 
with my former instruments, induced me to add +0",241 to 
Dr. Maskelyne’s determination of « Aguile: Mr. Pond has 
now added still more. But, neither of ae determinations has 
yet that agreement which might be desired in so momentous an 
object, the foundation of all astronomical observations. The 
probable error of Mr. Pond’s determinations is not pointed out ; 
that of mine is 0’,0235. It is therefore yet doubtful, whether 
there is here a constant error, or an a¢cidental one which would 
disappear by continued observations. In the mean time I have 
been desirous to know, what result the meridian circle of 
Reichenbach would give respecting it; and I have therefore cal- 
culated 25 observations of the sun from 27th March to 16th 
September 1820. According to these observations the amend- 
ment of my former catalogue is +0",006 in time; which is ab- 
* solutely imperceptible. It convinces me, however, that I should 
not be justified in deciding on the difference between Mr. Pond 
and myself; since the observations of one year (although they 
should be free of all constant errors of the instrument, as I have 
reason to believe is the ease with mine) are not yet sufficient to 
decide so nice aud difficult a point. According to my ideas, a 
long continuation of observations is requisite, if we wish to have 
the most accurate results. I have indeed sometimes found that 
a well according series of observations will deviate further from 
another series than the probable errors would lead us to uate 
rom, 
