Excerpt from The Archives of Internal Medicine, 1915, Vol. 16 Drs. Cannon, Erlanger, Hewlett, Hirschfelder, Moffitt and Wilbur returned the photographs with their marks; and these marks have all been transferred to the original photographic negatives which are herewith reproduced in Figures 1 to 6. Connected with each mark is a letter (arbitrarily assigned), which represents the one who chose that point for his reading, and a number, which shows in millimeters the displacement of mercury in the U-tube at the instant when this point was written. These numbers were Obtained by reference to the original drum records, which contain tracings Of a float in the mercury U-tube, together with its base line and, at the beginning and end Of each record, stationary marks. The manometer record was measured from the midpoint of its oscillations. 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.