Nikola Tesla U.S. Patent 1,061,142 - Fluid Propulsion Patent Wrapper Page 11

} } } ) } 24 8145 manner is, other conditions being equal, approximately propor\tionate to the active surface of the runner and to its effectre speed. For this reason, the performance of such machines augments at an exceedingly high rate with the increase of their size and speed of revolution. The dimensions of the device as a whols, and the spacing of the disks in any given machine will be determined by the conditions and requirements of special cases. It may be stated that the intervening distance should be the greater, the larger the diameter of the disks, the longer the spiral path of the fluid and the greater its viscosity. In general, the spacing should be such that the entire mass of the fluid, before leaving the runner, is accelerated to a nearly uniform velocity, not much below that of the periphery of the disks under normal working conditions and almost equal to it when the outlet is closed and the particles move in concentric circles. It may also be pointed out that such a pump can be made. without openings and spokes in the runner, as by using one or more solid disks, each in its own casing, in which form the machine will be eminently adapted for sewage, dredging and the like, when the water is charged with foreign bodies and spokes or vanes especially objectionable. Another application of this principle which I have discovered to be not only feasible, but thoroughly practicable and efficient, is the utilization of machines such as above described for the compression or rarefaction of air or gases in general. In such cases it will be found that most of the general considerations obtaining in the case of liquids, properinterpreted, hold true. -5811