-/So MAIZE 



CHAP, wards raked out and pointed with cement mortar. Stone 

 XVI - walls require only to have the joints of the outside face raked 

 out and pointed with cement mortar. 



753. Roof. — Any of the materials in general use may be 

 used for a roof covering, and any form of roof may be adopted, 

 provided adequate provision is made for filling the silo and 

 also for ventilating it during the process of fermentation. The 

 " lean-to" roof does not fulfil these conditions, and is seldom 

 used. The ordinary pitch roof with a gable at either end, or 

 the pyramidal or conical roofs shown on the accompanying 

 diagram, are undoubtedly the best forms, as they allow for 

 the filling door being placed either in the gable or on the slope 

 of the roof, and also admit of proper ventilation being arranged 

 for. With a roof of corrugated iron, which is the covering 

 most commonly used in South Africa, the slope of the roof 

 need not be very steep, and the timbers forming the trusses 

 need not exceed 4-,} inches x \\ inches, or 6 inches x 1 -\ inches 

 at most, according to width of silo. A ventilator should be 

 placed at the apex of the roof, and openings should be formed 

 at the eaves to create a draught and assist in carrying off the 

 foul air and gases rising from the silage. 



754. Boors, — The doors required for a silo consist of a filling 

 door placed in the gable or in the roof, above the highest point 

 to which the silage is filled, and three ">r four emptying doors 

 placed one above the other at converj.jnt intervals apart and 

 usually at one side of the building. The filling door should be 

 large enough to freely admit the carrier, say 2 feet 6 inches 

 wide and 3 feet to 4 feet high, according to available space, 

 and should be placed at the side most convenient for filling. 

 The cut fodder is conveyed straight from the cutting machine 

 through the filling door to the centre of the silo by means 

 of a carrier or an elevating tube, up which it is forced by air 

 pressure. 



The doors through which the silage is emptied should be 

 about 24 inches wide and 30 inches high, one at the top and 

 one at or near the level of the ground, and the others placed 

 at intervals of about 4 feet apart vertically. They should be 

 of well-seasoned timber, strongly made to resist the excessive 

 pressure and heat, close fitted to exclude all air, and placed 

 flush with the inside face of the wall. The doors ma)- be 



