240 The Evolution of Agricultural Implements. 
is with such an extraordinary diversity of conditions as it is 
required to meet. 
Passing over, then, as indescribable the labours of the 
men intervening between Meikle’s age and the present day, 
a brief account must be given of modern threshers, which may 
be classified either as double-blast, or finishing, and single- 
blast, or non-finishing machines. In the finishing machine the 
grain, after being threshed by the drum, is first separated from 
cavings and chaff, afterwards from dirt and seeds, and finally 
into different sizes of grain. It is in regard to the last two 
operations that modern improvements are most conspicuous. 
Only a few years back there were no machines capable of finish- 
ing for market unless the crop was in good condition ; now, 
good samples are obtained even from the foulest grain. 
This has been accomplished by incorporating with the thresh- 
ing-machine a cleaning and sizing machine called the “ second 
dresser,” which separates such chaff, seeds, or dirt as are not ex- 
tracted in the first dresser, while any uncleaned grain is returned 
to the riddle, whence it passes a second, or even a third, time 
through the drum. The thoroughly cleaned grain falls into a 
revolving screen, having three different-sized meshes, whence it 
is finally discharged, either as first, second, or third quality, into 
separate sacks, ready for market. The single-blast machine 
does not finish for market, but is used in threshing for the 
granary by farmers who do not intend to market their com 
immediately. 
Comes, of Market Drayton, was the first, in 1847, and Hayes, 
in 1853, to exhibit straw elevators, or stacking-machines, such 
as those already described, applied to the threshing-machine. 
Hayes’s plans were adopted and improved by Clayton and Shuttle- 
worth, but it was not till after the expiration of Hayes’s patent, 
in 18G7, that this useful instrument came into general use. In 
1879, Messrs. Nalder and Co. first exhibited a threshing-machine 
of which the stacker forms an integral part, the endless chain of 
rake teeth rising from its framework instead of from an inde- 
pendent carriage, and being arranged to swing around a sup- 
porting pivot, like a crane, so as to deliver the straw in any 
direction. 
Still more recently, in 1883, Messrs. J. and F. Howard, of 
Bedford, first succeeded in adapting the sheaf-binding apparatus, 
already described under Harvesting Implements, to the thresh- 
ing-machine. The straw coming from the straw-shaker is first 
“ packed,” and then bound with stilng, exactly as in the self- 
binding reaper, the trusses so bound being delivered to the 
stacker, if intended for the rick, to the cart, if for straw market. 
