194 AIR AND LIFE. 



contrary, on the decrease, and no new method Las been devised of late 

 to increase the quantity of force derived from this source. M. Maxi- 

 milian Plessner, however, has done good work in trying to call public 

 attention to the matter. 1 Wind is doubtless very irregular, by turns 

 strong or even violent, and a short time afterwards very gentle, and 

 even ceasing. But a great deal depends upon localities. There are 

 places and large regions where the wind is quite regular enough, as 

 far as strength and constancy are concerned, and near the seashore it 

 seldom fails. In the subtropical regions, also, trade winds are very 

 constant, and in most parts of the globe the regularity of the wind 

 increases with the altitude. The latter fact has been well shown by 

 a continuous series of observations made at the Eiffel Tower, in Paris, 

 since 1889. This amounts to asserting that, upon the whole, a consid- 

 erable part of the globe is perfectly suited for investigations upon the 

 best methods of deriving power from the winds. M. Plessner has cal- 

 culated that a wall or curtain 1,000 meters high placed upon the fifty- 

 fourth parallel between the twenty-fourth and thirty-eighth degrees of 

 longitude, would receive, through the impact of the wind, a total 

 sum of 100,000,000 horsepower, and 130 such walls would provide 

 13,000,000,000 horsepower, which means the power of 1,000 Niagaras. 

 Of course no such apparatus could be erected and used, as the first 

 storm would destroy the whole fabric ; but this helps us to realize the 

 tremendous amount of energy which speeds over our heads. The first 

 requisite is some sort of motor driven by the wind, and an accumulator 

 to store the energy and yield it at the required moment. M. Plessner 

 has no admiration for the old windmill ; he does not find therein the 

 motor which engrosses his thoughts or dreams. The aeolian wheel 

 would be more suitable, but this also is below his requirements, and 

 he is rather inclined to look upon sails as affording a possible solution 

 of the problem. "The utilization of the power of winds," he writes, 

 "and its transformation into mechanical work, are possible only by 

 means of sailing vehicles, driven by wind upon a circular railway, the 

 power generated by such rotation being transmitted to an axle, and 

 thence to machinery." He therefore proposes a circular railway, at 

 ground level, or, better still, elevated upon trestles. On this railway 

 a circular or annular train, made of small cars coupled together, each 

 carrying a mast and two sails at right angles with each other, is driven 

 by the wind. These sails are automatically trimmed, and automatically, 

 also, they expand or contract, or rather take in the wind or withdraw 

 from it. As long as the wind blows, the train continues rotating, and if 

 it is connected with a central axle, the latter may work dynamos and 

 charge electric accumulators. A similar apparatus might be arranged 

 in water, boats taking the place of the cars, and since the wind power 



1 See his book : Ein Blick auf die grossen Errinduugen cles zwanzigsten Jahrhnu- 

 derts — Die Dienstbarmachvmg der Windkraft fur den elektrischen Motoren-Betrieb, 

 Berlin, 1893. 



