THE PRINCIPLE OF THE WINDMILL 313 



supply there as in the cities, but that as a rule the farmhouses 

 obtain their drinking water from springs and wells. In poorer 

 houses, water is laboriously carried in buckets from the spring 

 or is lifted from the well by a 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 150 gallons per day. A strong man can 

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

 but if the well is deep, more 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. 



The principle of the windmill. 

 The toy pin wheel is a wind- 

 mill in miniature. The wind 

 strikes the sails, and causes rota- 

 tion; and the stronger the wind 

 blows, the faster will the wheel 

 rotate. In windmills, the sails 

 are of wood or steel, instead of 

 i paper, but the principle is iden- FlG - l8 s- The toy pin wheel is a 



i miniature windmill. 



tical. 



As the wheel rotates, its motion is communicated to a mechan- 

 j ical device which raises water as long as the wind continues to 

 blow. 



