This is a standard set of tables designed for Marine navigation. Although there are 6 volumes in a set, only those pertaining to the latitudes anticipated need to be obtained. Their tabular data, being purely mathematical results, never go out of date. The latitudes listed for the Volumes work for either northern or southern hemisphere. This six-volume series of Sight Reduction Tables for Marine Navigation is designed to facilitate the practice of celestial navigation at sea by the Marcq Saint Hilaire or intercept method. The tabular data are the solutions of the navigational triangle of which two sides and the included angle are known and it is necessary to find the values of the third side and adjacent angle. The tables, intended for use with The Nautical Almanac, are designed for precise interpolation of altitude for declination by means of interpolation tables which facilitate linear interpolation and provide additionally for the effect of second differences when required.