Nikola Tesla U.S. Patent 1,061,206 - Turbine Patent Wrapper Page 7

C T 1 } } 9071 a peculiar impediment known as "lateral" or "skin resistance", which is two-fold, one arising from the shock of the fluid against the asperities of the solid substance, the other from internal forces opposing molecular separation. As an inevitable consequence a certain amount of the fluid is dragged along by the moving body. Conversely, if the body be placed in a fluid in motion, for the same reasons, it is impelled in the direction of movement. These effects, in themselves, are of daily observation, but I believe that I am the first to apply them in a practical and economical manner in the propulsion of fluids or in their use as motive agents. In an application filed by me Octoper 21st, 1909, Serial of which this case es a division V Octoper per 20 Number 523,832, I have illustrated the principles underlying my discovery as embodied in apparatus designed for the propulsion of fluids. The same principles, however, are capable of embodiment also in that field of mechanical engineering which is concerned in the use of fluids as notive agents, for while in certain respects the operations in the latter case are directly opposite to those met with in the propulsion of fluids, and the. neans employed may differ in some features, the fundamental laws applicable in the two cases are the same. In other words, the operation is reversible, for if water or air under pressure be admitted to the opening constituting the outlet of a pump or blower as described, the runner is set in rotation by reason of the peculiar properties of the fluid which, in its movement: through the device, imparts its energy thereto. The present application, which is a division of that referred to, is specially intended to describe and claim ry 871