place, reduced under the
same superintendence and on the same general principles, and compared
throughout with the same theoretical Tables.'--After reference to the
great value of the Greenwich Lunar Observations to Prof. Hansen in
constructing his Tables, and to the liberality of the British
Government in their grants to Hansen, the Report continues thus: 'A
strict comparison of Hansen's Tables with the Greenwich Observations
of late years, both meridional and extra-meridional, was commenced.
The same observations had, in the daily routine of the Observatory,
been compared with the Nautical Almanac or Burckhardt's Tables. The
result for one year only (1852) has yet reached me, but it is most
remarkable. The sum of squares of residual errors with Hansen's Tables
is only one-eighth part of that with Burckhardt's Tables. When it is
remembered that in this is included the entire effect of errors and
irregularities of observation, we shall be justified in considering
Hansen's Tables as nearly perfect. So great a step, to the best of my
knowledge, has never been made in numerical physical theory. I have
cited this at length, not only as interesting to the Visitors from the
circumstance that we have on our side contributed to this great
advance, but also because an innovation, peculiar to this Observatory,
has in no small degree aided in giving a decisive character to the
comparison. I have never concealed my opinion that the introduction
and vigorous use of the Altazimuth for observations of the Moon is the
most important addition to the system of the Observatory that has been
made for many years. The largest errors of Burckhardt's Tables were
put in evidence almost always by the Altazimuth Observations, in
portions of the Moon's Orbit which could not be touched by the
meridional instruments; they amounted sometimes to nearly 40" of arc,
and they naturally became the crucial errors for distinction between
Burckhardt's and Hansen's Tables. Those errors are in all cases
corrected with great accuracy by Hansen's Tables.'--The Report
concludes with the following paragraph: 'With the inauguration of the
new Equatoreal will terminate the entire change from the old state of
the Observatory. There is not now a single person employed or
instrument used in the Observatory which was there in Mr Pond's time,
nor a single room in the Observatory which is used as it was used
then. In every step of change, however, except this last, the anc