Excerpt from Journal of the Asiatic Society of Bengal, Vol. 43: Part II., Natural History, Nos. I to IV, 1874 The name of Duplex Telegraphy has been given to that mode of Electric Telegraphy which admits of the simultaneous transmission in opposite directions of signals between two stations through a single wire. That this name is far from happily chosen, is evident but, as it is current and has already gained a recognized footing, it is not considered advisable to endeavour to replace it now by a more rational one, and it will therefore be adhered to throughout this paper. In the following investigation I shall endeavour to develop the mathematical theory of Duplex Telegraphy in its most general form, with the object of determining not only the best arrangement for any particular method, but also the relative values of different methods. It 1s manifest that having from general considerations decided on the best method, and further determined the best arrangement for this method, the remaining difficulties, due to the nature of the problem itself, will be exhibited in a clearer light, and the means of overcoming them may then be more easily discerned. 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.