i'Ki-:sini:.\ riAL AouhM-ss — skctiox a. 



31 



wnccl ant(ini;itically. so as to ])r(.'vciU datnaj^c in a storm, and to 

 <lcsi.y^n the wheel so that no veerinj^" is necessary, tlic wheel 

 working;' e(|uall\ well with the wind blowing in any difection. 

 The windmill, h'ig. 12. designed by the late Professor Blyth. 

 of the (ilasgow Technical College, is worth}' of notice as fnl- 

 fdling both objects. 



Fig. 13 shows another similar design in which th.e veering- 

 is assisted by two tnrbine wheels carrying a vane, and monnted 

 on a horizontal axis. 



Many attempts have been tnade to constrnct large-power 

 windmills; one snch is shown in I-"ig. 14. bnt is not likelv ever 

 to be erected. 



Wind-power, it will therefore be seen, can never hope to 

 be a serious rival to fnel for motive-power pnrposes. 



Fk;. I. 



-Windmill ('Asij^urd Id wnrk with the wind hl(i\vin<-; in any 

 (lircotio!!. 



J Tare and Tidal Energy. — The ntilisation of the energy 

 of waves and tides has always had a fascination for many 

 inventors, some of them engineers of high standing. The total 

 mechanical power of the world is said io have been doubled 

 dnring the past 20 years or so. and fears that, shonld this 

 increase continne. the world's snpplx of fnel, now by far the 

 principal source of power, will l)ecome exhausted, have given 

 rise to many inventions for the utilisation of the enormous 

 power going to waste in the tides. The majorit\- of these 

 pro])Osals are exceedingly crude, and mechanically are quite 

 impossible, although some invetitors are sanguine enough to 



