240 Mr. Baily on the Solar Eclipse 
will be found that the centre of the moon's shadow, on that 
meridian, had only reached the parallel of about N. lat. 32^°: 
and as the semi-diameter of the umbra was not more than 
forty-seven and a quarter English statute miles, or about two- 
thirds of a degree, the eclipse could not there be total to the 
northward of N. lat. 33^°. Now, since the place where Aga- 
thocles landed in Africa, was probably not situated below the 
parallel of N. lat. 34 0 , it is evident that he did not, in any part 
of his course (and much less, at the commencement of it), come 
within a considerable distance of the moon’s umbra. 
I much doubt whether, according to our present computa- 
tion, this eclipse was total even at Tripoli: and, although it 
was unquestionably of considerable magnitude, both there and 
as far north as Syracuse itself, yet ( for the reasons already 
given in this paper) I do not think that, at any intermediate 
place between these two cities, it could be so great as to pro- 
duce that degree of obscurity, which is recorded by Diodorus 
and confirmed by Justin. In order that the phenomenon 
should accord with the fact, as related by these historians, the 
centre of the moon’s shadow ought to pass over, or very near 
to, Malta : that is, the latitude of the moon ought to be, at 
least, three degrees greater than our present tables make it. 
Since the latitude of the moon depends on her true distance 
from the node, these observations (if correct) will show the 
necessity of some alteration in the table of the secular variation 
of the moon’s mean distance from her node, which (agreeably 
to the rule given by M. Laplace) is deduced immediately 
from the secular variation of her mean longitude. These re- 
marks, however, are thrown out merely as hints to those who 
