A Manual of Field Astronomy

Abstract

THIS is a handy and lucid manual dealing with all the problems that arise in field work with a theodolite, namely, determinations of altitude, latitude, azimuth, time, and longitude. It contains a useful list of formuke for obtaining any element of the astronomical triangle in which three elements are supposed to be known. Attention may he directed to the unusual notation; the polar distance, zenith distance, and colatitude are called z, p, and s respectively; this is because they are opposite the points Z, the zenith, P, the pole, and S, the star. The explanations refer throughout to the American Ephemeris, but the arrangement of the British Nautical Almanac is so similar that they will serve equally for it. All needful corrections, such as parallax and refraction, are explained, but the author deliberately refrains from introducing refinements that are of no importance for work in the field. It is evident from a study of the examples that the degree of accuracy contemplated by the author is only of the order of the nearest 10″ A considerably higher degree of accuracy is attainable with field instruments of the finest type, but the methods explained in the book will suffice, if carefully followed, to give this greater refinement. A Manual of Field Astronomy. By Andrew H. Holt. Pp. x + 128. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1917.) Price 6s. net.