Excerpt from American Engineer and Railroad Journal, 1902, Vol. 76 Tests, should, however, be made, I believe, with several sizes of stacks, as it is possible that a down draft or rather a partial return of exhausted gases to the front end may occur, and if this is the explanation for some statements that have been made about the drop in efficiency caused by long front ends, it would also be advisable to run a series of tests under actual conditions at several Speeds, in each case t'rying, say three lengths and carefully noting the vacuum and velocity of the gases at several points. 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.