SECTION V.

Of Practical Agriculture, and its necessary Instruments.

We begin this part of our subject with a few remarks on the instruments necessary to agriculture, which may be comprised under the well known names of the plough, the harrow, the roller, the threshing-machine, and the fanning mill.

I. Of the plough:

It is among the inscrutable dispensations of Providence, that the arts most useful to man, have been of later discovery—of slower growth, and of less marked improvement, than those that aimed only at his destruction.—At a time, when the phalanx and the legions were invented and perfected, and when the instruments they employed were various and powerful, those of agriculture continued to be few, and simple, and inefficient.

Of the Greek plough, we know nothing; and the general disuse of that described by Virgil and Pliny, furnishes a degree of evidence, that experience has found it incompetent to its objects.—With even the boasted lights of modern knowledge, scientific men are not agreed upon the form and proportion, most proper for this instrument. As in other cases, so in this, there may be no abstract perfection; what is best in one description of soil, may not be so in another; yet, as in all soils, the office of the plough is the same, viz. to cleave and turn over the earth, there cannot but be some definite shape and proportions, better fitted for these purposes, and at the same time less susceptible of resistance, than any other.

This beau ideal, this suppositious excellence, in the mechanism of a plough, has been the object of great national, as well as individual research. In Great Britain, high prizes have been established for its attainment; and in France, under the ministry of Chaptal, 10,000 francs, or $2000, were offered for this object, by the agricultural society of the Seine. In both countries, the subject has employed many able pens; those of Lord Kaimes, of Mr. Young, of Mr. Arbuthnot, of Lord Somerville, and of Messieurs Duhamel, Chateauvieux, Bosc, Guillaume, &c. It is not for us, therefore, to do more than assemble and present such rules for the construction of this instrument, as have most attained the authority of maxims.

1st. The beam, or that part of the plough which carries the coulter, and furnishes the point of draft, should be as near that of resistance as possible; because the more these are approached, the less is the moving power required. Even the shape of the beam is not a matter of indifference. In the old ploughs, it was generally straight, but a small curve is now preferred; because it has the effect of strengthening the coulter, by shortening it.

2d. The head of the plough, is the plain on which it moves. This should be concave, because that form offers fewer points of friction, and, of course, less resistance. Between the beam and the head, is an angle, on which depends the principal office of the plough; the making, at will, a deep or a shallow furrow. If you wish a deep furrow, diminish the angle, and vice versa: but this angle should, in no case, exceed from 18 to 24 degrees.

The resistance made to the plough being produced less by the weight of the earth, than by the cohesion of its parts, it is evident, that the head should be shod with iron, and rendered as smooth as possible. This remark applies equally to the soc and to the mould board.

3d. The soc, in its widest part, should be larger than the head. It has different shapes in different countries. In some is given to it that of an isosceles triangle; in others, that of the head of a lance; in Biscay, that of a crescent; and in Poland, of a two pronged fork. But, whatever be its shape, it should be well pointed and polished—enter the earth with facility, and cut it easily.

4th. To the mould board, some workmen give the shape of a prismatic wedge; others make the upper part convex, and the lower concave; while many make it entirely flat. In stiff soils, the semi cycloid is the form to be preferred, and in loose friable soils the semi-ellipsis.[7] The iron mould boards have great advantages over the wooden, particularly when they, the shear and the soc, form one piece, as in the plough of Mr. Cook.

It is a general opinion, that a heavy plough is more disadvantageous than a light one; because the draft of the former, being greater, will be more fatiguing to the cattle: but the experiments of the agricultural society in London, establish a contrary doctrine, and show, that in light grounds, the labour is more easily and better performed, with a heavy, than with a light plough.

5th. The coulter is a species of knife inserted in the beam, and so placed before the soc, as to cut the sod. It is susceptible of being raised or depressed at will.

6th. The handles of the plough ought to be made of some kind of heavy wood, that they may operate as a counter-weight to the head, the soc and the mould-board.

To these remarks we subjoin two sets of experiments made with the most approved French and English ploughs; that of Guillaume, and Small's Rotheram plough improved, which furnish a means of comparison between the best ploughs of Europe and those of this country.

The resistance (stated in these tables) was measured and ascertained by a dynonometer, a machine, indispensable to those who would make correct observations on the relative advantages of different ploughs.

The French Plough.The English Plough.
Resistance in pounds.Resistance in pounds.
1stexperiment200 1stexperiment360
2ddo.2402ddo.380
3ddo.2003ddo.480
4thdo.2204thdo.460
5thdo.2205thdo.400
6thdo.400
Divided by5)10807thdo.420
8thdo.386
Average,2169thdo.440
Divided by9)3720
Average,413

II. The Harrow. This is of different kinds—the triangular and the square, the single and the double. But of whatever form, its uses are the same; to smooth the field after ploughing, to break and pulverize the clods, and to cover the seed.—These uses sufficiently indicate the propriety of employing two in succession; one of heavy frame, with few and long teeth, like the Scotch brake; the other, of lighter constitution, with more and shorter teeth. Our own experience leads us to believe, that the common harrow covers the seed too much, because small seeds will not vegetate at a depth greater than three inches.

III. The Roller is a cylinder of heavy wood, turning on gudgeons, or on an axle, and placed in a frame, to which is attached a shaft; it is of different dimensions, but need not exceed that which may be drawn by one, or at most by two horses or oxen. This instrument is indispensable in good husbandry, yet is rarely used in ours. Its offices are three-fold—to render loose soils more compact; to break the clod on stiff ones, and on both, to compress the earth, (after seeding) so that it be every where brought in contact with the grain. It is also usefully employed in reinstating the roots of meadow grasses, loosened and raised by the alternate freezing and thawing of the ground, and, with similar view, may be passed over winter crops early in the spring.

Its clod-breaking and pulverizing property is much increased, by surrounding the roller with narrow bands of iron, two inches broad, three inches thick, and six inches asunder; or by studding it with iron points, resembling harrow teeth, and projecting three or four inches.

IV. The Threshing Machine is of English invention, and may be well enough adapted to the taste and circumstances of rich amateurs, but not at all to those of farmers in general. Our objections to it are three—the first cost, which is great; the quantum of moving power employed, which is equal to that of six horses, and the number of hands required to attend it, which is not less than four. We have seen, in France, a machine for the same purpose, but of much simpler structure—called the "Rouleau de depiquer" which is only a fluted cylinder; yet simple and cheap as this was, it could not maintain itself against the more ancient instruments—the flail and the horse. Still it is to be hoped, that new experiments may succeed better and abridge the manual labour usually given to this branch of husbandry, and, that the mechanical genius of our own country (which is not inferior to that of any other) may be the first to combine power and cheapness in this machine.

This hope is probably suggested, by the description of a new invented threshing machine, now before me, and which I may be permitted to transcribe from the letter of the inventor. "The machine I have built, is three feet wide. One horse will thresh with much ease, as much wheat as can be laid on it, by one man, (the straw to be taken away by another,) say, from fifty to one hundred bushels in a day, and the saving of grain will pay for the labour; for, I think, that with good attendance, not a particle of grain can escape with the straw.—The expense of the machine will be from fifty to seventy dollars, exclusive of the moving power, which is a wheel, about ten feet diameter, on an upright shaft, to which a lever is fixed to hitch the horse. Into this main wheel, a small one should be made to work, about two feet diameter, on a shaft carrying a drum, four feet wide. With this simple gearing, and drawn by a horse that walks well, the machine will give about eighteen hundred strokes in a minute, and if fully attended, will, without hard labour for the horse, thresh a bushel every three or four minutes. It stands in my barn, and may be seen and examined by any one."[8]

V. The Fanning Mill. Other things being equal, the cleanest wheat is most easily preserved, and, on manufacture, gives the best flour, and in the largest quantity. These considerations offer inducement enough for the employment of this machine, which, however, besides doing its business well, saves a great deal of time. It is too well known to require description.

ON BONES, &c. AS MANURE.

The carbon and hydrogen abounding in oily substances fully account for their effects; and their durability is explained from the gradual manner in which they change by the action of air and water.

Bones are much used as a manure in the neighbourhood of London.—After being broken and boiled for grease, they are sold to the farmer. The more divided they are, the more powerful are their effects. The expense of grinding them in a mill would probably be repaid by the increase of their fertilizing powers; and in the state of powder they might be used in the drill husbandry, and delivered with the seed in the same manner as rape cake.

Bone dust, and bone shavings, the refuse of the turning manufacture, may be advantageously employed in the same way.

The basis of bone is constituted by earthy salts, principally phosphate of lime, with some carbonate of lime and phosphate of magnesia; the easily decomposed substances in bone are fat, gelatine and cartilage, which seems of the same nature as coagulated albumen.

According to the analysis of Fourcroy and Vauquelin ox bones are composed

Of decomposable animal matter,51
phosphate of lime,37.7
carbonate of lime,10
phosphate of magnesia,1.3
100.

M. Merat Guillot has given the following estimate of the composition of the bones of different animals.

Phosphate of lime.Carbonate of lime.
Bone ofCalf,54
Horse, 67.51.25
Sheep,705
Elk,901
Hog,521
Hare,851
Pullet,721.5
Pike,641
Carp,455
Horses'Teeth,85.5 25
Ivory,"641
Hartshorn, 271

The remaining parts of the 100 must be considered as decomposable animal matter.

Horn is a still more powerful manure than bone, as it contains a larger quantity of decomposable animal matter. From 500 grains of ox-horn, Mr. Hatchett obtained only 1-5 grains of earthy residuum, and not quite half of this was phosphate of lime. The shaving or turnings of horn form an excellent manure, though they are not sufficiently abundant to be in common use. The animal matter in them seems to be of the nature of coagulated albumen, and it is slowly rendered soluble by the action of water. The earthy matter in horn and still more that in bones, prevents the too rapid decomposition of the animal matter, and renders it very durable in its effects.

—[Davy's Ag. Chem.