Excerpt from Proceedings of the Washington Academy of Sciences, 1909, Vol. 11: March-December, 1909 The dihexagonal prism faces are bright but rounded, so that no accurate measurements could be made. They gave, however, a bright signal in the mass of reflections caused by the rounded sur faces and the measurements given below were of this bright signal. The faces are seen to be in the prism zone mm' and therefore could not be scalenohedrons with complex indices. 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.