Excerpt from Transmission of Power by Fluid Pressure: Air and Water It is clear an incomprehensible fluid like water, subject to no changes except freezing, which can easily be guarded against, must be a much better medium for transmitting power than an elastic fluid like air, which cannot be compressed without great increments of pressure. The absolute energy imparted to the air during compression is equal to the equivalent in work of the number of thermal units required to raise the temperature of the air to that due to adiabatic compression, and must therefore be wholly lost, if the air without doing work is cooled down to the original temperature of the free air. The work done by expansion down to atmospheric pressure after cooling corresponds to an equal loss of the absolute energy possessed by the air before compression. This cooling-down to the temperature of the medium surrounding the pipes is inevitable, when the air is transmitted to considerable distances, unless the pipes are coated with some nonconducting substance. Heat must also be lost in the very act of compressing the air. The whole work done in the cylinder of the air pump during one full stroke consists of two operations. (1) Work done in raising the tension of the air to the required tension. 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.