THE IRRIGATION AGE. 



233 



the center of the pit. By means of a horizontal arm, 

 having a hoe or spade fastened at one end, and the 

 other end fastened to the center pole, in such a way 

 as to swing around, the pit can be dug straight, and the 

 sides can be made smooth. This method is to be 

 especially recommended when a silo of large diameter 

 is dug. 



The mortar used for plastering should be made 

 of 2 parts of clean sand and one part of cement, with 

 enough soft water to make it of suitable consistency 

 to adhere to the dirt wall. 



If the silo is 26 ft. in depth and 12 ft. in diameter, 

 then there will be about 1,000 square feet to plaster. 

 If two coats of cement plaster are applied each about 

 y 2 inch in thickness, then 

 about 84 cubic feet of 

 mortar are required. 

 About 3 yards of clean 

 sand and about 40 sacks 

 of cement will be needed. 

 If the wall is dry, wet it 

 before the cement mortar 

 is applied. 



The total amounts of 

 gravel, sand and cement 

 needed for a silo 26 ft. in 

 depth and 12 ft. in diam 

 eter are about as follows : 



For curbing, 2.1 

 yards clean gravel (2 

 loads) and 11 sacks of ce- 

 ment. 



For plastering, 3 

 yards clean sand (3 

 loads) and 40 sacks of 

 cement. 



This coat of plaster 

 on the dirt wall may be 

 put on considerably thin- 

 ner. Each applied coat 

 could be made as thin as 

 l /4 inch in thickness. This 

 would lessen the cost of 

 the silo considerably, but 

 it would also lessen the 

 strength and durability. 



If the subsoil is sha- 

 ley, and crumbles when 

 exposed to the weather, it 

 may be difficult to make 

 the plaster adhere by the 

 ordinary method of plas- 

 tering. In such a case the 

 mortar may be thrown on, 



and then smoothed. In extreme cases fine-meshed 

 woven wire, or the regular steel lath, may be fastened 

 to the dirt by means of wire hooks driven into the side. 

 Then no difficulty will be encountered in making the 

 cement mortar adhere. This, however, will add to the 

 cost of the silo. 



The bottom of the silo may be covered with a 

 two-iaOh layer of concrete. This, however, is not 

 necessary. The silage may rest directly on the ground. 

 A small amount of bottom silage may mold and spoil. 

 From a practical standpoint, this amount of spoiled 

 silage is so small, that it need not be considered. 



Fig. 2. Hoisting Dirt, While Digging a Pit Silo. 



If the labor necessary for digging the silo has 

 to be hired, and a heavy coat of cement plaster is used, 

 then a pit silo is about as expensive as an ordinary silo. 

 The pit silo should be covered in some way 

 to prevent any one from falling into the pit, to prevent 

 rain, snow and other foreign matter from entering, to 

 protect the silage from freezing, and to protect the 

 silage wall from being exposed to the elements. This 

 latter is likely to cause caving. 



The cheapest and simplest way of covering a pit 

 silo, probably is to place a post on the side of the 

 silo farthest from the barn. The post should be at 

 least 8 feet above the ground. Nail a 2x6 plank 

 ( having straight grain) to the side even with the top 



of the post. The other 

 end is fastened to the side 

 of the shed or barn. This 

 2x6 placed edgeways 

 above the center of the 

 silo furnishes a good sup- 

 port for the top of the 

 rafters, and also for fast- 

 ening a device for hoist- 

 ing the silage out of the 

 silo. The lower end of 

 the rafters can be fast- 

 ened to the sill on top of 

 the concrete curbing. 

 This frame work may be 

 covered with a composi- 

 tion roofing or with sheet 

 galvanized iron, or with 

 boards and shingles. 



The rafters may also 

 be placed so that all of 

 the upper ends are fast- 

 ened, and meet at a point 

 directly above the center 

 of the silo. The lower 

 ends are nailed to the 

 plate bolted on. the top of 

 the foundation. The roof 

 in this case is similar to 

 the roofs put on ordinary 

 silos. More labor is per- 

 haps required for build- 

 ing a roof of this kind. 



Getting the silage out 

 of a pit silo is not difficult. 

 There are several ways by 

 which this can be accom- 

 plished. The first 12 feet 

 of silage can be thrown 

 out with a pitchfork. If 



the silo is small and only a few cows are being fed, 

 then the silage can easily be carried out in a box or in 

 sacks. If a considerable number of cows are fed 

 silage, then some hoisting device should be installed. 

 A hoisting apparatus put in one of the state ex- 

 perimental silos works very well, and it is cheaply in- 

 stalled by home labor. It consists of a block and 

 tackle with rope fastened to the top part of the cov- 

 ering directly above the center of the silo. The end 

 of the hoisting rope is fastened to a home-made wind- 

 lass on the side of the covering for the silo. A box 

 of suitable size (2 ft. x 4 ft. x 3 ft.) having rope ban- 



