on," the deviations become nearly ten times as large as they were
before; a circumstance which might be expected to have some influence in
the decision of the question.

There is, however, another light in which it is impossible to avoid
looking at this singular oversight. The second column of the table of
latitudes must now be considered the true one, as that which really
resulted from the observations. Now, on examining the column of true
latitudes, the differences between the different sets of observations is
so considerable as naturally to excite some fear of latent error, more
especially as nearly the greatest discordance arises from the same star,
Alph.Lyrae, observed after an interval of only three days. It becomes
interesting to every person engaged in making astronomical observations,
to know what is the probability of his being exposed to an error so
little to be guarded against, and so calculated to lull the suspicions
of the unfortunate astronomer to whom it may happen.

In fact, the question resolves itself into this: the true latitude of
a place being determined by sets of observations as in the first of the
following columns--

Latitudes as
True latitudes observed. computed by a mistake
of Capt. Sabine's.

deg.min.sec. deg.min.sec.
Alph.Lyrae, 28th Aug.... 2 31 22.0 2 31 42.4
Alph.Lyrae, 29th Aug.... 31.8 43.8
Alph.Pavonis, 29th Aug... 44,0 44.5
Alph.Lyrae, 31st Aug.... 42.6 44.6
Alph.Cygni, 31st Aug.... 39.2 42.0
Alph.Gruris, 2d Sept.... 27.4 42.2

what are the chances that, by one error all the latitudes in the first
column should be brought so nearly to an agreement as they are in the
second column? The circumstance of the number of divisions of the
level being almost arbitrary within limits, might perhaps be alleged as
diminishing this extraordinary improbability: but let any one consider,
if he choose the error of each set, as independent of the others, still
he will find the odds against it enormous.

When it is considered that an error, almost arbitrary in its law, has
thus had the effect of bringing discordant observations into an almost
unprecedented accordance, as at Maranham;