147 



Improvements on the I'brt thing-Mill *. 



It is probable that several improvements will still be 

 made on this machine. Amongst these, diminishing the 



* Mr Robert Ker states, that Mr Dun, a very ingenious 

 mill-wright at Coldstream in Berwickshire, has made many 

 useful improvements on threshing-mills, in particular on 

 those which go by wind ; more especially, by causing the 

 machinery to regulate the sails in proportion to the wind and 

 work, in a most effective manner, with no trouble whatever 

 to the people who feed the mill. He has likewise adapted a 

 series or" buckets, resembling the chain-pump, which continu- 

 ally return all ill-threshed grain, particularly ill-humbled bar- 

 ley, to the threshing stai;e ; and has, be-ides, added an in- 

 geniously-devised shaker, beyond the rake, for clearing all 

 the loose grain from among the straw. On the whole, the 

 machines erected by Mr Dun, Mr Ker is of opinion, have 

 carried the threshing mill to its utmost perfection ; always 

 supposing, however, that they possess sufficient moving power 

 of water or wind ; for they re rather too much loaded to be 

 driven with any tolerable ease by horses. 



The greatest objection to horse-machines, is the severity of 

 labour which they require, besides often necessarily occupy- 

 ing the time of the farm draughts, when much wanted f r 

 other purposes. The capital defect of the threshing-mills 

 which are driveen by wind, is the extreme uncertainty of 

 that power. During the long-continued frosts of winter, 

 when there is hardly any wind, they are often altogether use- 

 less for weeks, when straw for litter and fodder cannot be 

 dispensed with ; and the same thing sometimes happens dur- 

 ing harvest, when straw is much wanted for thatch. Water- 

 mills, whire that power can be hid, are certainly the best in 

 every respect ; being more economical and steadier in their 

 operation, than when driven either by horses or wind. But 

 water is very apt to fail in autumn, and during long frosts. 

 On theie accounts, both wind and water machines, except 

 when the latter have an ample and ready supply of the mov- 

 ing power, ought to be provided with horse wheels. 



