MOTIVE POWER PROM WAVE MOTION

Globe, Volume III, Issue 296, 25 May 1875, Page 4

MOTIVE POWER PROM WAVE MOTION

At the Institute of Naval Architects, on March 18th, a paper of some colonial interest was read by Mr B. Tower, " On a method of Obtaining Motive Power from Wave Motion." Mr Tower's work on this subject originated in the proposals of Mr Spencer Deverell, of Portland, Victoria. The paper commenced with an analysis of the nature of wave motion and a computation of the mechanical effect obtainable by the particular form of apparatus designed by the author upon the general principles enunciated by Mr Deverell a year or two ago at the Royal Society in Melbourne. Some experiments were described, in which a small working model was tested in the open sea at Torquay, Mr William Froude, F.R.S, being present on that occasion in a boat with the designer of the machine. The result of this trial showed that the principle employed was correct, although the form of the model was wholly unsuitable for use on a large scale. A further amended model was subsequently made, and this was shown after the reading of the paper. The main principle of this model shows that power is obtainable by the use of heavy weights fixed at the end of two levers, the weights being balanced at the short arms of the levers by metal springs. The vertical movements of the ship cause these heavily weighted levers to be depressed and raised in such manner that each lever describes regular revolutions round a vertical plane. Another model was also exhibited by the lecturer, viz, a small three-foot model of a ship fixed in a sheet of indiarubber. Some mechanism below on being worked caused the model to oscillate like a ship against a head sea. A small wave engine with its revolving loaded arm was fixed in the body of the ship, and the oscillations imparted to it caused the arm to revolve and turned a screw. A good deal of interest was shown in the exhibition of this novel principle of propulsion. The paper proceeded to sketch an imaginary voyage of a vessel of 1100 tons displacement with a 100 ton weight revolving in a circle of 40ft diameter. It was shown that in ordinary waves, 6ft high and 10 seconds period, the ship would go ahead six knots with the wave machine alone ; also, in tropic calm, with swell 3ft high and 10 seconds period, she would go four knots and pass the belt of calms in two and a half days. The writer endeavoured to show that the machine would be specially valuable in going against a head wind and sea. After the reading of the paper Mr Froude and Mi Scott Russell and others testified to the scientific accuracy of the principle of the machine. Mr Russell, however, hoped that a practical trial of the machine would be made to determine doubts which he had as to the practical applicability of the principle on a large scale. The writer informed our reporter that he proposes to deal with the practical application of the matter in a subsequent paper to be read before the Mechanical Section of the British Association at Bristol in August next. The present paper was only intended to promulgate the principle involved, and this, in his opinion, had beer: sufficiently one.