264 FARM MACHINERY 



700 feet, while i-inch pipe would need only about 26 feet 

 of head to secure the desired flow. 



373. Wells. The type of pump used will often depend 

 upon the kind of well. Wells are divided into four 

 classes : (a) dug or bored wells, (b) driven wells, (c) tubu- 

 lar wells, and (d) drilled wells. Dug wells are those 

 from which the earth is removed by a bucket, rope, and 

 windlass. These wells are either walled with stone or 

 brick or cased with wooden or tile curbing. Bored wells 

 belong to the same class except the earth is removed 

 from the well with an auger. Pumps for dug or bored 

 wells are independent of the casing, and any common 

 type may be used provided the cylinder is placed within 

 the proper distance of the water. Driven wells are made 

 by attaching a point with a screened opening to permit 

 of a flow of water to the casing, usually i^-inch galvan- 

 ized pipe, and the whole driven to sand or gravel strata 

 bearing water. A driven well does not extend through 

 rock strata. Tubular wells are made by attaching a 

 cutting edge to the well casing, which is usually made 

 of pipe 2 inches in diameter, and which is sunk into the 

 opening made by a drill which operates inside of the 

 casing. The earth and chips of stone are removed by a 

 stream of water which flows out through the hollow drill 

 rod in the form of a thin mud. A screened sand point 

 similar to those used in driven wells is placed in the 

 bottom of the well after it has been finished. A turned 

 flange is provided which prevents the point from pass- 

 ing beyond the casing. A pit 6 feet deep and 4 feet 

 square, walled with brick, stone, or cement, should be 

 placed around driven and tubular wells to permit of the 

 use of underground pumps, or to provide a vent hole to 

 prevent water freezing in the pump standard during cold 

 weather. It is an advantage to have the well at least 6 



