34 



PRESIDENTIAL ADDRESS— SECTION A. 



presses air into a receiver, and this compressed air drives a 

 dynamo by means of an air motor. The remaining method 

 dei)ends upon the greater motion of the surface water as com- 

 pared with water at a greater depth, the vertical axis with 

 attached pistons tending to remain stationary while the cylinders 

 attached to the floats by their reciprocating motion circulate oil 

 through a rotarv engine, which in turn drives a dvnamo. 



h'lG. \'j. — Paddle wlieels propelled by tlu' surf. 



Many of the wave-motors so-called depend for their action 

 on the horizontal travel of the water. One such surf-machine 

 is shown in Fig. 17. Paddle-wheels, carried on floats, by their 

 rotation due to the motion of the Avatcr to and fro. operate air- 

 compressors. 



An arrangement by which a trolley carrying a series of 

 plates is driven by the surf \\\^ the beach, lifting meantime a 

 weight to facilitate its return, is shown in Fig. iK. 



I'lc. 18. — l)e\ice for obtaiiiinj; power from the surf. 



The next arrangement ( JMg. M)) for lUilising the surf has 

 occurred to many in\entors. The iiUention is to utilise the 

 enormous torce of the waves on a sleej), rock\- shore, air being 

 compressed into cells, formed in concrete ])\- the incoming water, 

 the return of the compressed air being ])re\ente(l b\- automatic 

 valves on tlie (leli\er_\ pi]K's. 



It does not appear likelx that much useful i)ower is going 

 to be gained by wrive and stnf motors. There is alwavs the 



