G B Airy, Esq. F.R.S. Astronomer Royal. The Lecturer commenced
by remarking that he should not have thought the calculations
connected with any other eclipse a subject worthy of his
audience. The eclipse commonly called that of Thales is however
one of extraordinary interest. It refers to a point of time
which connects in a remarkable way the history of Asia Minor and
the Greek colonies settled there with the history of the great
Eastern empires. Its precise date has been for a long time a
subject of discussion among the ablest astronomical computers
and chronologers. It shows in a remarkable degree the power of
astronomy; for it is no small thing that we are able to go back
so many centuries and confidently to describe a phenomenon which
then occurred, almost to its minutest features. But it shows
also the weakness of astronomy. It requires the combination of
theory and observation, with a full sense of the possible
inaccuracies of both, and with an endeavour by the use of each
to correct the failings of the