206 



THE FARMER'S MAGAZINE. 



PLOUGHS AND PLOUGHING. 



BY AN AJIEEICAN. 



We resume our notice of Mr, French's views on " plow- 

 ing." The nest point which our Transatlantic friend 

 proceeds to consider, is " the influence of velocity on the 

 draft." 



" We are accustomed (he observes) to associate the idea of 

 increased speed with that of greatly increased power. With 

 regard to ships, canal-hoats, and tlie like, it is considered a 

 general rale, that in doubling the velocity of a body moving 

 through a fluid, that body not only impinges on twice as 

 many particles of the fluid, but on each of them with twice 

 its former force, so that the resistance increases as the 

 squares of the velocity. The velocity of locomotives on 

 railways is limited by various circumstances, so that it is 

 well understood that a low rate of speed is far more econo' 

 mical than a higher rate. But the resistance opposed to 

 the plougli in its work is mainly attributable to one principle 

 — that of friction ; and it is a well established proposition 

 that friction is not in general increased by an increase of 

 Velocity. In accordance with this principle, the results of 

 careful experiments with the dynamometer, with the same 

 teams and ploughs, at various rates of speed, indicate no 

 difference whatever in the draught of the plough, when at 

 work at the speed of 1 A miles and 8 J miles per hour. It was 

 found, however, that although the average draught was sub- 

 stantially the same at any rate of speed between IJ and 5 

 miles an liour, j'et that the oscillations in draught were greatly 

 increased — that is to say, that the draught at a slow rate was 

 more regular than at a higher rate of speed. This is readily 

 accounted for, because of obstructions in the soil, A stone; 

 for instance, upon which the ploughshare should strike with 

 double the usual velocity, would cause a momentary in- 

 crease of draught, followed by a decrease as the plough 

 ''hould slip past it. 



"The principles thus practically established, that increase 

 of velocity in ploughing involves no increase of draught, is 

 of the highest importance as respects the question whether 

 slow or fast-moving animals should be employed in this 

 ■work. An ox-team, moving at the rate of 1^ miles per 

 hour, will plough an acre, turning a furrow 9 inches wide, 

 in 7 hours and 20 minutes ; while a horse-team, moving a 

 the rate of 2f miles per hour, will accomplish the work in 

 i hours ; and the actual power exerted on the plough is the 

 same in both cases. Hence the importance of employing 

 active animals in all labour of this kind for which they are 

 suited. Slow animals like oxen cannot, with or without a 

 load, be driven rapidly ; but within the natural walking pace 

 of the animals employed, there seems to be an actual waste 

 of power in proportion to the increase of the time employed 

 upon the ploughs ; or, in other words, the same force is 

 exerted every moment of eight hours in ploughing an acre 

 at a given width and depth of furrow, as is exerted in the 

 4 hours in which a horse-team may perform it at a fast 

 walk. 



" There is, however, another element which cannot he 

 estimated by the dynamometer or any other instrument, 

 yet should enter into our consideration of this topic. Every 

 animal in moving, with or without a load, carries the bur- 

 den of his o\wi body ; and it is probably true that this bur- 

 den 19 somewhat in proportion to his weight, and to the 



speed with which he moves. To illustrate this, we have 

 only to look at the facts developed by the dynamometer in 

 plougliuig over hills. It is found that the draught of the 

 plough is very little varied by ploughing up or down a 

 descent; while every farmer knows very well that his team 

 walks much harder in ascending than in descending. So, 

 if a team be driven up a steep hill without a load, the ani- 

 mals obviously exert themselves more than in moving at the 

 same pace on level ground. The greater difficulty of 

 ascending may be partly accounted for upon the common 

 principles of gravitation. In raising himself to the top of 

 a hill, to a position 20 feet higher than he before stood, the 

 animal has exerted as much power, in addition to his effort 

 on the level, as would be mathematically necessary to raise 

 the same dead weight the given height in the same time ; 

 and something more may be added for the distorted action 

 of the muscles, and in ploughing for the disturbance of the 

 true line of draught. Even upon level ground, it requires 

 some exertion for any animal to move, and this exertion is 

 probably proportioned in some measure to the rapidity of 

 the motion. Any calculation upon this pomt, based upon 

 the difficult theories of momentum, would be of no 

 practical value. Assuming, as we may, upon the facts dis- 

 closed by the experiments referred to, that the draught of the 

 plough is not substantially increased by the velocity of its 

 movement, it is for the farmer to consider the natural pace 

 of his animals, the saving of time of his labourers, as 

 ploughmen or drivers, by rapid work, the increased danger 

 of injury to team or implements where the work is obstructed 

 by stumps or stones, and he must make the best practical 

 use of the developments of science made for his benefit." 



The fifth j)oint considered by Mr. French is, " The in- 

 fluence of wheels of various kinds upon their draught, and 

 their utility ;" and upon this head he says : — " The greater 

 part of the ploughs used in England are supported by two 

 wheels, one on each side of the beam, usually arranged so 

 that one wheel runs in the furrow and the other on the 

 unploughed land, there being a difference in their radius of 

 about the depth of the furrow. They are, however, sepa- 

 rately adjustable, so as to be changed to gauge furrows of 

 different depth. The theory, as stated by a farmer who was 

 defending the use of the old Norfolk plough, with its high 

 wheels, is plausible enough, in favour of wheels, 'The 

 draught of the plough,' said he, ' results from its friction on 

 the furrow-slice, and on the bottom of the furrow ; and 

 whatever weight rests upon the wheels is taken from the sole 

 of the plough, and relieves the draught so much as the 

 difference between rolling and dragging friction.' 



" Various trials have from time to time been made in 

 England with a view to determine the influence of wheels 

 upon the draught. Mr. Handley's trials, reported in the Jour- 

 nal of the Royal Agricultural Society, made with four 

 different ploughs, indicated an advantage from the use of 

 wheels of about 1.5 per cent. Mr. Pusey's experiments 

 made the difference still greater, amounting to 23 per cent, 

 in favour of the wheels. Mr. Morton, in a series of care- 

 fully conducted experiments, made with full knowledge of 

 the previous trials by the other gentlemen named, arrives 

 at the conclusion that when a plough is properlyj^set, the 



