When you visit our website, if you give your consent, we will use cookies to allow us to collect data for aggregated statistics to improve our service and remember your choice for future visits. Cookie Policy & Privacy Policy
Dear Reader, we use the permissions associated with cookies to keep our website running smoothly and to provide you with personalized content that better meets your needs and ensure the best reading experience. At any time, you can change your permissions for the cookie settings below.
If you would like to learn more about our Cookie, you can click on Privacy Policy.
Chapter 7—The Base of the Triangle The work undertaken by the Commission was a triangulation for the purpose of measuring an arc of meridian. Now the direct measurement of one or more degrees by means of metal rods would be impracticable. In no part of the world is there a region so vast and unbroken as to admit of so delicate an operation. Happily, there is an easier way of proceeding by dividing the region through which the meridian passes into a number of imaginary triangles, whose solution is comparatively easy. These triangles are obtained by observing signals, either natural or artificial, such as church-towers, posts, or reverberatory lamps, by means of the theodolite or repeating-circle. Every signal is the vertex of a triangle, whose angles are exactly determined by the instrume