The new U.S. Hydrographic Office publication H.O. 249, Sight Reduction Tables for Air Navigation, comprises three volumes: Volume I covers all latitudes and contains tables of altitude and azimuth of selected navigational stars; Volume II contains tables of computed altitude and azimuth angle for latitudes 0°–39°, declinations 0°–29°; and Volume III contains tables of computed altitude and azimuth angle for latitudes 40°–89°, declinations 0°–29°. The tables have been produced jointly by the American Nautical Almanac Office and H.M. Nautical Almanac Office for the U.S. Hydrographic Office. The British edition of the tables is being published by H.M. Stationery Office as A.P. (Air Publication) 3270; the actual tables are identical with the American edition but the introductory matter has been reset.