The Nautic-Astronomical and Universal Calculator

Abstract

IN many numerical processes there has been too great a tendency on the part of computers to employ more decimal places than are necessary, and to use logarithms where more direct methods would be effective. The introduction of mechanical contrivances for the performance of arithmetical operations has brought the problem of a possibly greater simplification of calculation more to the front, with the result that some neglected resources have been made available. One outcome has been the improvement in accuracy and ingenuity in construction of sliding scales for obtaining an approximate solution of many simple problems. With increased usefulness, however, comes a tendency to increase the number of moving parts and to give greater variety to the system of dividing, but this more complicated mechanism often destroys the simplicity of construction which is one great merit in the sliding scale. Certainly, the invention described by Mr. Nelting does not err on the side of simplicity. The inventor claims for his calculator that it will give the logs, of numbers, with their squares and square roots; the values of trigonometrical functions of sine, tangent, cosecant and cotangent of angles, whether expressed in time or in arc; tables of reciprocals with their squares and square roots. In addition to many other combinations, the scales can be used for facilitating or completely solving problems required in nautical astronomy connected with altitude, longitude, and latitude, with an accuracy sufficient for the purposes of navigation. Unfortunately, we have not had an opportunity of studying the mechanism, and the rules that are given for its use are not easily followed when the necessary constructions cannot be made. Moreover, the description is obscure in many parts.