on Agricultural Implements. 



589 



ficant, nor, unless the ground be unusually baked, from the act 

 of severing the earth, but from two other causes, namely, friction, 

 and, on certain soils, still more from cohesion. Now if the soil 

 contain sharp sand there will be no cohesion; it will work freely 

 off the mould-board, which will be kept bright, and the shorter 

 its surface the less will the friction be. For such soils, therefore, 

 as are common in Scotland short mould-boards may be the best. 

 But most Enjjlish soils contain so much clav as will adhere to 

 and fill up the hollow of a short mould-board, so that the furrow- 

 slice will have to work not upon an iron surface but upon ihe 

 most disadvantageous of all surfaces, one of rough loam, and the 

 draught may thus be easily doubled by friction and cohesion 

 together. Hence our English mould- boards have been very 

 properly lengthened, the more properly, I suppose, because the 

 same soil will more often have to be worked in a moist state here 

 than in continental Europe.* Many of the foreign ploughs, it 



* Since the above remarks were written, I have received the subjoined report from 

 Baron Mertens ; but from my own former experience in dynamometrical trials, I am 

 J)Ound to say that I should not draw from a sirrj^le summer-trial any inference even as 

 to the lightness of a plough in ordinary work, and still less as to its capacity for 

 general work. When land is hard and dry, cleavage is the principal element of 

 resistance ; the friction is limited, and the cohesion, of course, null. Hence our 

 English ploughs which seemed the lightest were brought, in a former trial, to a dead 

 stand on moist clay. The American ploughs are very elegant and light, but seem 

 hardly steady enough for breaking up an English clover-ley. The Belgian mould- 

 board is good, though the framework is as unsuited to our workmen as our own would 

 be to theirs. — Ph. P. 



" London, July 29, 1851. 

 " The trial of the following prize ploughs with Bentall's dynamometer took place on 

 the 25th instant, at Mr. Mechi's farm, near Kelvedon, Essex, before Col. Challoner, 

 Mr. Johnson, and myself. Morin's dynamometer (French) could not be tried, on 

 account of llie rain. The trials were attended with great success, as you will perceive 

 by the following results : — 



Ploughs. 



Name. 



Points of 

 Resistance. 



Remarks. 



1. Belgian 





527 



Land very hard going up 









hill, coming down in Ball's 

 plough's furrow. 









2. American . 



Hale and Spear . 



530 



Land liard. 



3. English 





540 



Land worked well. 



4. French 





540^ 





5. Holland . 



Jenken 



55Ui 





6. Belgian 



Delstanclfe .... 



568 



No })loughmen to use them- 

 well. 



7. English . 



Howard 



569 



Hard land. 



8. American . 



Proutv and Mears . 



579 





9. French 



Talbot, 



580 





10. English . 





640 



Very hard ground ; veyy 

 good furrow. 



11. Ditto . . 



Ransom e and May . 



659 



Very hard piece of land. 



Baron MERTJiNS d'Ostins. C. B. Challoner. 



Baron Mertens, for Mr. Johxson." 



