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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Excerpt from The Interferometry of Reversed and Non-Reversed Spectra It will be convenient to refer to the cases in which one of the two coincident spectra from the same source is rotated 180 with reference to the other on a transverse axis an axis parallel to the Fraunhofer lines), under the term reversed spectra; while the term inverted spectra is at hand for those cases in which one of the paired spectra is turned 180 relative to the other on a longitudinal axis an axis parallel to the r - o length of the spectrum). In this book the latter are merely touched upon, briefly, in Chapter I, but they are now being investigated in detail and give promise of many interest ing results. The chapter contains a full account of what may be seen with a single grating - the linear phenomenon, as I have called it, and which, if it stood alone, would be difficult to interpret. In Chapter II, therefore, the interferences of reversed spectra are treated by the aid of two gratings, in virtue of which a multitude of variations are inevitably introduced. The phenomena are thus exhibited in a way leading much more smoothly to their identification. 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.

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.