THE PRINCIPLE OF THE WINDMILL 181 



houses, water is laboriously carried in buckets from the spring 

 or is lifted from the well by the windlass. In more prosperous 

 houses, pumps are installed ; this is an improvement over the 

 original methods, but the quantity of water consumed by the 

 average family is so great as to make the task of pumping an 

 arduous one. 



The average amount of water used per day by one person 

 is 25 gallons. This includes water for drinking, cooking, dish 

 washing, bathing, laundry. For a family of five, therefore, the 

 daily consumption would be 125 gallons ; if to this be added the 

 water for a single horse, cow, and pig, the total amount needed 

 will be approximately 1 50 gallons per day. A strong man can 

 pump that amount from an ordinary well in about one hour, but 

 if the well is deep, m^^e time and strength are required. 



The invention of the windmill was a great boon to country 

 folks because it eliminated from their always busy life one 

 task in which labor and time were consumed. 



177. The Principle of the Windmill. The toy pin wheel is 

 a windmill in miniature. The wind strikes the sails, and 

 causes rotation ; and the stronger 

 the wind blows, the faster will the 

 wheel rotate. In windmills, the 

 sails are of wood or steel, instead 

 of paper, but the principle is 

 identical. 



As the wheel rotates, its motion 

 is communicated to a mechanical 

 device which makes use of it to 

 raise and lower a plunger, and 

 hence as long as the wind turns FlG - I2 4- T T f he ^. p ! n .^ heel is a 



miniature windmill. . 



the windmill, water is raised. 



The water thus raised empties into a large tank, built either 



in the windmill tower or in the garret of the house, and from 



