Book Reviews

Abstract

THESE two year-books of scientific information annually increase in value by the addition of new data and revision of the old. The Annuaire of the Bureau of Longitudes has undergone several changes. In the astronomical part the tables of mean positions of stars supposed to be variable have been omitted, the tables of the elements of minor planets have been curtailed, and in the same way the number of coordinates referring to the orbits of double stars has been diminished. The table of elements of periodic comets only observed at a single apparition has been transferred to the Connaissance de Temps, but comets observed at a return are retained in the volume. The chapter on tides has been rearranged and revised, and new tables inserted. M. Moureaux contributes three new charts showing the magnetic elements in France, based on direct observations; the charts are for the epoch January 1, 1896. M. Berthelot brings up to date the tables in the section on thermo-chemistry. The articles in the Annuaire are all interesting. MM. Lœwy and Puiseux contribute a paper on recent progress in the knowledge of the lunar surface, obtained by means of photography; M. Poincaré contributes a valuable paper on the stability of the solar system; an account of Fizeau's scientific work is given by M. Cornu; and M. Janssen describes the work done at the observatory on the summit of Mont Blanc in 1897. Finally, there is an address by MM. Janssen and Lœwy, delivered on the occasion of M. Faye's jubilee last January.