6 FARM BUILDINGS IN SOUTH AFRICA 



The arrangement of the machinery is simple, all power being trans- 

 mitted by belt. The engine-house is cheaply constructed as a lean-to 

 against the silo. E is an oil-engine, or a suction gas-engine might be 

 installed if the power required exceeds eight horse-power. T is the 

 cooling tank for the cylinder-jacket circulating water. This is generally 

 a galvanised, corrugated iron tank, which is better placed outside the 

 engine-room than inside it. The engine drives an overhead counter shaft 

 which extends across the silo end of the feed-room. The broken line, 

 shown in the plan between engine-house and cow-byre, is intended to 

 indicate the edge of a roof sheltering the main-drive belt, the fast and 

 loose pulleys on which it runs, the end-bearing and wall-bracket, and the 

 end of the counter shaft. From the counter shaft the mealie grinding 

 mill, GM, and the ensilage cutter, EC, are driven, the belt of the latter 

 passing through an orifice in the wall of the feed-room. From the second 

 overhead shaft the root pulper, RP (or other machine), and the chaff- 

 cutter, CC, are driven. The ensilage cutter may be used to cut chaff 

 if desired, being placed in the position CC for the purpose. From the 

 counter shaft other machines, if required, might be driven ; if this is done 

 it might be advisable to make the feed-room a little larger. 



The chaff-cutter elevates, or blows, the chaff into the chaff store 

 through an orifice immediately under the eaves. The ensilage cutter 

 elevates (generally by means of an air blast from a fan) the ensilage into 

 the silo through the filling door in the roof of the silo ; this door is shown 

 in the front elevation. 



In arranging belt-driven machinery it is as well to keep the following 

 points in view : — 



1. The tight or driving side of a belt should, if possible, be the 



lower. This is because if the slack side is on the top it hangs 

 down on to the pulley rims, and thus the extent of contact 

 between belt and pulleys is increased. On the other hand, 

 if the slack side of the belt is below, it hangs away from 

 the pulley rims, and hence the extent of contact is diminished. 

 It is especially desirable to have the slack side on top in 

 the case of the main- drive belt from the engine. 



2. Provided the above condition is satisfied a slightly inclined 



belt will run more satisfactorily than one which is exactly 

 vertical, i.e. in which the centre line of the one shaft is 

 vertically over that of the other. 



