Book excerpt: Excerpt from Proceedings of the First Conference on Scientific Research in the National Parks, Vol. 2: New Orleans, Louisiana, November 9-12, 1976 Analysis by season (figure 2) indicates only one significant change. Fall seems to be a cleaner time than other seasons. An examination of the data reveals that nearly all of the data points for Fall were obtained in 1975. Since the rest of 1975 is in no way exceptional, it seems probable that the data reflect a real phenomena, however we have no ready explanation for its cause. 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.