Excerpt from Hand Book on Vacuum Cleaning Plants: A Treatise for the Use of Architects, Drawing Specifications for Cleaning PlantsAll standard makes of motors have the same characteristics, and little is to be said on this point, except that medium speed motors should be used and speeds should be kept under revo lutions per minute in general, and pref erence given to slow speed motors.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.