The Compass, Vol. 3: A Monthly Journal for Engineers, Surveyors, Architects, Draughtsmen, and Students, 1893-1894 (Classic Reprint) - Hardcover

William Cox

Hardcover

ISBN 10: 033211290X ISBN 13: 9780332112909

Publisher: Forgotten Books, 2018

Synopsis

Excerpt from The Compass, Vol. 3: A Monthly Journal for Engineers, Surveyors, Architects, Draughtsmen, and Students, 1893-1894

C E, Fig. 5, touch a circle, and from the point of contact A a straight line A B be drawn cutting the circle, the angles CA B and B A E, which this line makes with the line touching the circle, shall be equal to the angles A D B and A F B which are in the alternate segments of the circle. Thus, in the figure, the angle A 0 B at the centre of the curve being known 2 a, the angle in the segment A D B =c A B 180° a. Set the vernier of the instrument to the angle thus found, and taking any position, say D, supposed to be in or near to the required curve, hold up the instrument, the observer facing towards the centre of the curve. If the images of a rod at A and another rod at B coincide in the two prisms vertically, then the point D is in the required curve, but if they do not coincide, the observer must shift his position until they are brought into coincidence. In this manner, and by the simple use of the rods at A and B, any number of points in the curve may be found.

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Edition details

• Publisher: Forgotten Books
• Publication date: 2018
• ISBN 10: 033211290X
• ISBN 13: 9780332112909
• Binding: Hardcover
• Language: English
• Number of pages: 177