46 Trial of the Meridian Cirele, 
From the change of the daily-and annual temperature, the de- 
gree of light, &c. &c. as well as from the reductions which must 
be applied in observations, small errors may arise, which perhaps 
we shall never learn how to bring into account; but which, by 
a continuation through several seasons, we may render of less 
importance. 
If we deduct the mean difference of the two catalogues from 
the several differences above given, the result of Mr. Pond’s in- 
dividual determinations in reference to mine will more clearly 
appear ; and as this comparison gives occasion for some obser- 
vations, I will here insert it. 
y Pegasi «. —0,072 at Libre to en 
a Arietis : — 0,057 a? os we = O085 
a Ceti eo. —0,135 a Corone .. —0,012 
« Tauri -» +0,038 a Serpentis .. —0,919 
a Aurige .. +0,043 a Scorpii .. —0,198 
B Orionis .. +0,026 # Herculis .. +40,035 
6 Tauri -» +0,0€8 a Ophiuchi ., +0,090 
a Orionis .. +0,120 a Lyre .. +0,044 
a Canis Maj. +0,020 y Aquile  .. 40,011 
« Gemin. .. +0,113 a .» ee —0,005 
a Canis Min. +0,1038 B of Ses 
6 Gemin. .. +0,053 a' Capricorni —U,079 
a Hydre .. +0,164 ae— —.. —0,135 
« Leonis .. +0,121 - a Cygni .. +0,023 
B oa ee, = 0G5 a Aquarii .. —0,065 
6 Virginis .. +0,030 a Piscis Aust. —0,235 
a -- —0,020 a Pegasi .. —0,046 
a Bootis .. +0,044 a Androm. ... —0,003 
It is certainly difficult to form an agreement in the hundredths 
of the second of time; and, with half the stars, the differences 
are below 0’,05. But it is yet very improbable that these dif- 
ferences should all have arisen from accidental errors of obser- 
vations. We may even perceive a regularity in their march ; 
for, in the vicinity of « Canis minoris, the positive quantities 
clearly preponderate; whilst in the southern stars, the negative 
are most numerous. The first of these discrepancies would be 
explained if, in my catalogue, « Canis minoris (which star is a 
point of comparison for the others) were incorrectly determined; © 
and, in fact, if it were one-tenth of a second too small. This 
however is improbable; since its determination is founded on — 
75 observations. Yet it cannot be denied that the stars, situ- 
ated at a distance of 12 hours from each other, offer the greatest 
difficulties ; partly from the going of the clock, and partly from 
the 
