230 Eocj-yerimental Inquiry on Draught in Plmighing. 





Surface Drauglitj 



\'\'^eiglit of Plougli^ 





in Stones. 



in Stones. 



1. Ferguson's swing • 



12 



15 



2. Clark's swing « 



12 



15 



3. Hart's wheel « 



3 



12 



4. FF, wheel . 



8 



131 



5. FF, swing . . 



10 



. lOJ 



6. King's swing 



8 



8 



7. King's wheel 



6 



10 



8. Old Berks wheel . 



8 





9. Rutland, wheel 



8 



15 



The first thing which struck me in the numbers of the first 

 column is the very large proportion of labour which the mere 

 dragging of the implement bears to the whole task of the horse. 

 The entire labour incurred by a pair of horses in making a 

 5-inch furrow on the sandy land of this day's trials, with Clark's 

 Scotch ploughs is 17 stone; and since 12 stone of these are given^ 

 as we see^, to the plough itself, 5 stone only can be required for 

 cleaving and turning over the soil, the real object to be performed. 

 It is a striking fact, that, upon such land, it costs the horses as 

 much labour to move the Scotch iron swing-ploughs along the 

 surface as to plough the ground at 5 inches with Hart's one- 

 wheeled plough, namely, 12 stone in both cases. At 4 inches 

 Hart's plough working drawls but 11 stone. 



But further — since, if w e deduct the surface-draught of a plough 

 from its draught when at work, the remainder represents the power 

 which it causes the horse to expend in moving a given portion of 

 soil — it appears that by making this calculation for several ploughs 

 we should be able to compare the merits of those parts of them 

 which act on the land. I took, therefore, the draughts of the 

 ploughs in cutting a 5-inch furrow on the sandy field at Hatford, 

 and subtracted from each their surface-draughts respectively : — 







Gross Draught 



Surface Draught 



Remainder 







in Furrow 



which is to be 



or working 







5x9. 



deducted. 



Draught. 



1. 



Ferguson's 



19 



12 



7 



2. 



Clark's 



17 



12 



5 



3. 



Hart's 



12 



3 



9 



4. 



FF, wheel 



13 



8 



5 



5. 



FF 



16 



10 



6 



6. 



King's swing 



15 



8 



7 



7. 



King's wheel 



17 



5 



12 



8. 



Rutland , 



16 



8 



8 



9. 



Old Berkshire 



21 



8 



13 



Here the situation of the Scotch ploughs and of Hart's is 

 strikingly changed. When at work the two former were half as 

 heavy again as the latter : it now appears, however, that this great 



