The Theoretical and Measured Pumping 

 Power of Windmills. 



liV K. C. MURl^HV. 



For more than a year the writer has devoted a large portion of 

 his spare time to the stud}' of windmills — trying to verify or dis- 

 prove statements of windmill manufacturers of the power of their 

 mills, adapting the mathematical theor\- of windmills in general to 

 the American steel windmill of today, measuring the power of 

 windmills, and in reconciling theoretical and measured results. 



The writer hopes in the near future to supplement the present 

 paper with a more extended set of measurements. 



There is toda}' a large demand for powerful windmills mills 

 that will pump a large amount of water in a short tinu'. The 

 cause of this tiemand is the need of water for irrigating purposes, 

 and a cheap and efficient moter to raise water from water-bearing 

 strata. The windmill has come into competition with gasoline, gas, 

 and even steam engines for this purpose, and there is a demand foi' 

 accurate information in regard to the merits of each, and especiall_\' 

 in regard to the power of windmills. 



(It:;) KA.\. r.MW gr.vn. \()i,. iv, no. ;J. oct.. IHit.') 



