The Determination of Latitude and Longitude by Photography

Abstract

LATITUDE and longitude may be determined on shore with considerable accuracy by means of an ordinary photographic camera; and this method will, I think, prove useful for several reasons. The observation part of the business, which consists in taking the photographs, is separated from the measuring and calculating part, and may be performed by different persons at different times and places. For taking the photographs no scientific apparatus is wanted besides the camera and a watch, the latter to measure intervals of not more than a few hours with an accuracy of a second or so. Anyone may easily be instructed to take the photographs, as no mathematics and very little astronomical knowledge are wanted, only the measuring of the plates and the calculation requiring some scientific training.