1880-1920] ROYAL ASTRONOMICAL SOCIETY 219 astrodynamics, is not provided for in any national establishment in this country. The functions of the Nautical Almanac office are limited to the more or less mechanical production of the Nautical Almanac ; but in the working out of the mathematical theories of sun, moon, and planets, or in the building up of tables on the basis of such theories, that institution takes no part whatever. And yet the ephemerides in the Nautical Almanac are computed from these tables. As the Nautical Almanac office was now in charge of a very distinguished worker in astrodynamics, the medallist of that day, it was more than ever desirable that this country should not be left entirely behind in these matters, but that an additional assistant of high mathematical attainments and a couple of computers be added to the existing staff of the office. Gill was very much in earnest and was not content with merely throwing out a suggestion. In May of the same year (1911) he brought the matter before the Council of our Society. A small Committee was appointed, from which a report was received in 1912 January. This followed very much the same lines as Gill's address, referring to the brilliant work of Newcomb in the office of the American Ephemeris,* and to the Lunar Tables founded on Delaunay's theory, recently brought out by the Bureau des Longi- tudes. The Committee repeated the proposal made by Gill as to the enlargement of the Nautical Almanac office. But the matter got no further ; Gill died in 1914 January, and six months later came the deluge. It is very much to be hoped that this question may be reopened under favourable conjunctures. While on the subject of gravitational Astronomy we may refer to a piece of work initiated by the Council and carried out under its general supervision. In the Greenwich Observations for 1859, places of the moon from Hansen's tables were given for midnight of every day on which the moon had been observed at Greenwich, from 1847 to 1858. The comparison of these places with those of the Nautical Almanac gave the excess of Hansen's places over those of Burckhardt, and it was assumed that this might be adopted without sensible error for the time of observation, so that the differences of Hansen's places and the observed places might be found thereby. The procedure was, however, not strictly correct, as the change of the quantity H B in the course of some hours was by no means always insensible. It seemed, therefore, desirable to make the calculation of the differences H B more
- In 1897 January, when Newcomb was about to retire from the office of
Superintendent of the American Ephemeris, the Council passed a resolution to the effect that they had learned with great regret of the possibility of his work on planetary tables and the lunar theory being interrupted, and desired to put on record their sense of the great importance to Astronomy of the com- pletion of this work. A copy of this resolution was sent to Newcomb.
