140 EG YP TJAN A GRTC UL TURE. 



wind carries the chopped straw and chaff obliquely to a 

 distance, while the heavy grain falls nearly vertically to 

 the ground. 



The cost of thrashing and winnowing a feddan of wheat 

 by the norag may be estimated at from ninety to one 

 hundred and twenty piastres. 



The thrashing machine with straw bruising apparatus 

 is constructed to suit the requirements of countries where 

 the straw must be chopped and bruised as in Egypt. This 

 machine is represented in Fig. 40 and its method of work- 

 ing may be described as follows : The machine is driven 

 by means of a belt connecting the thrashing drum with 

 the fly-wheel of an engine which is generally one of 12 H.P. 

 The drum, from which the motions of the varioas parts 

 of the machine are developed, has a speed of from nine 

 hundred to one thousand revolutions per minute. The 

 crop is fed into the drum which, by a beating and rubbing- 

 process, separates the grain from the ear. The straw is 

 then carried by the shakers (which by their oscillating 

 motion disengage any loose grain from the straw), to the 

 cutting drum where it is chopped and thereafter falls into 

 the bruising drum from which it is ejected on to the sifter. 

 The latter is perforated so that any grain which may have 

 escaped the shaking process is intercepted. Simultaneously 

 the grain falls through the thrashing drum concave on to 

 the riddles, which are driven by means of a cranked axle. 

 The riddles are perforated to allow of the grain falling to 

 the first dresser, while the chaff and short straw are car- 

 ried to the bruising drum. The first dressing apparatus is 

 fited witth a blower which, by creating a blast of air, 



