Rensselaer Republican, Volume 22, Number 11, Rensselaer, Jasper County, 21 November 1889 — NEW USE FOR WATER. [ARTICLE]

NEW USE FOR WATER.

A Stream Three-Quarters of an Inch In Diameter. A new boat is expected to make the unusual speed of. twenty-five miles an hour. Her propelling power will be a stream* of water discharged from a nozzle three-quarters of an inch in diameter,-at the stern. It has been practically demonstrated to the satisfaction of scientists that the impact of a column of water swiftly delivered under the surface against the body of water the ship floats in has precisely the same resuiting reaction upon the vessel as if the stream were discharged against a solid wall beside the vessel. This achievement does not rest upon the results obtained, in 1 boratory processes merely, but has been proved in the aetu 1 working of a steam launch of forty tons burden, the Prima Vista, which, with a hull not modeled for speed, with an ordinary engine and without a vacuum pump, attained a speed of twelve miles an hour by the projection of a stream of water onequarter of an inch in diameter. The pressure of the column of w ter was 900 pounds to the square inch, and the nozzle discharged 320 pounds of water 1 per minute at a velocity of 380 feet a second. | These f icts were determined by Dr. Walter M. Jackson, of Rhode Island. He has spent more than eighty thousand dollars in his experiments nd for the new boat, the Evolution. The latter is 100 feet long. Her drafight is only 3 feet, and her floor is almost flat, , The tendency in propulsion will be tqi drive her out of r.ither than under the water. By the use of steele for the boil- I er. hollow pistons, ribbed cross heads and aluminum where that metal is appropriate. the weight has been reduced 30 per cent and Dr. Jackson, who regards this construction as but a step toward his ideal, expects ultimately to get twice the power with one-fourth the weight ol this apparatus. The pressure of the jet of water is 2,500 pounds to the square inch, abd the nozzle will deliver 900 gallons a minute at a velocity of 600 feet a second. Among other advantages gained, the drag of a screw astern is obviated. A rudder, except an auxiliary one to be shipped if necessary, is also dispensed with, the 9liip being steered by a deflection of the current of water. A nozzle at the bow, brought into action by simply reversing the lever, delivers a stream forward to stop a boat or back her. Other appliea ions of the jets of water are under consideration. The saving in the direct application of power over the use of a screw pro- i peller is estimated at more than 30 per ! cent. The space occupied by the engine is much less than that required by an ordinary marine engine, and it has the further advantage of being horizontal in its position in the vessel instead of being set up vertically. Dr. Jackson says that with a pressure of 3,000 pounds to the square inch through a three-quarter inch nozzte the Etrutria, one of the largest ocean steamships, i could bo driven twenty miles an hour. No disturbance of the water is made eighteen inches from the nozzle.