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2847. Mud walls with a mixture of straw, were formerly frequent in many places, not only for surrounding small enclosures and stack-yards, but also for constructing the walls of farm-houses and offices, and for subdividing houses into different apartments. When either the outside walls, or the inside divisions of a house are made of these materials, the custom is, to take a small quantity of straw, and incorporate it with a sufficient proportion of clay; the straw in this case answers the same purpose as hair in plaster-lime. When a sufficient number of these are made, the work is begun by laying a stratum at the bottom of the intended wall; when this is done, and the different pieces firmly kneeded, or wrought together with the hand, a flat deal board is applied on each side, which being properly pressed, and rubbed against the building in a horizontal direction, not only serves to consolidate the work, but gives it a degree of smoothness and uniformity; successive stratums are added, till the wall is raised to the intended height, taking care to taper it gradually upwards. Walls made in this way, if properly constructed, will last for many years, and if dashed or harled with lime, at a proper season of the year, will have an appearance no way inferior to such as are made with stone and lime, along with this addition to their appearance, the harling or dashing with lime, if properly done, will, by preventing the access of moisture, render them much more durable.

2848. Rammed earth, or en pisé walls, are very common in France, both as fences and walls for buildings. They have been described at great length in the communications to the Board of Agriculture, and in other works, and tried in various parts of this country with tolerable success, though they are by no means suited either to our moist climate, or degree of civilization. In constructing them the earth is previously pounded, in order to crumble any stones therein; clay is added thereto in a small quantity, about one-eighth part. It is all beaten and mixed up together by repeated blows with a mallet about ten inches broad, and ten or fifteen inches long, and two inches thick. The earth being thus prepared, and slightly wetted, the foundation of the wall is dug; this is laid with stone, and when it is about one foot high above the surface of the ground planks are arranged on each side, and the space between filled with the earth intended for the wall. It is strongly beaten; and this method is continued successively, till the wall is completed. 2849. Stamped earth walls are the invention of Francois Cointeraux. Earth prepared in the same manner as for rammed walls, is put into a mould or box of any size, generally that of the proposed wall's thickness in width, one or two feet long, and about one foot high (fig. 395 a). The mould is a strong oaken or iron box, and the earth being placed in it, is compressed either by the action of a press acted on by a lever or screw, or a stamping engine 395 similar to the pile driver, or great forge hammer. The stone, or solid body of earth (b), thus acquired, is then used in the same way as common hewn stone, and either bedded or merely jointed with lime mortar; it is then washed or harled, both for effect and duration.

CHAP. V.

Of Gates appropriate to Agriculture.

2850. The gate may be considered as a moveable part of a fence, or as a frame of timber, or iron, readily moved and calculated to give a convenient inlet and outlet to enclosures. Gates may be considered in regard to the principles of their construction, and fixing; the materials of which they are made; and their different kinds.

396

e

2851. With respect to construction the great object is, to combine strength with lightness. The absolute strength of materials depends on their hardness and tenacity. A gate, therefore, consisting of one solid plate of wood or iron, would seem to require most force to break or tear it in pieces. But this would not be consistent with lightness and economy, and in the use of such a gate it would be found to open 'and shut with more difficulty, than one less strong. The skeleton of a plate of wood or iron is, therefore, resorted to by the employment of slips or bars, h disposed and joined together on mechanical principles. These principles, applied to carpentry, direct the use of what are called ties and strutts, in the judicious composition of which, as far as construction is concerned, consists the whole art of carpentry. A tie (fig. 396 a.) is a bar, or piece of timber, so placed in a structure as to resist a drawing or twisting power; a strutt (b) is one so placed as to resist weight, or whatever has a tendency to press or crush. The horizontal bars of a gate are all ties; the diagonal and perpendicular ones strutts. On the judicious combination of these ties and strutts, depends the absolute strength of the gate; and on their light

ness, and on the general form of the gate, depends its adaptation for opening and shutting by means of hinges.

2852. The construction of a gate best adapted for opening and shutting, is next to be considered. All gates, after being hung, have from their gravitation a tendency to deviate from their original position, to sink at the head or falling post, and thus no longer to open and shut freely. If the construction and hanging of the gate were perfect, this could not possibly take place; but as the least degree of laxity in trussing the gate, or want of firmness in fixing the post in the ground, will occasion, after frequent use, a sensible depression at the head, it becomes requisite either to guard against it as much as possible, in the first construction; or to have a provision in the design of the upper hinge (fig. 397.), for rectifying the deviations as they take place.

2853. In order to understand the construction best calculated to resist depression, suppose a gate hung, and resting on its heel (fig. 396 c, acting as a strut, and maintained there by its upper hinge (d), acting as a tie, then the bottom rail of the gate considered as representing the whole, becomes a lever of the second kind, in which the prop is at one end (c), the power at the other (g), and the weight placed between them in the line of the centre of gravity of the gate (i). Now, as two equal forces, to hold each other in equilibrium, must act in the same direction, it follows that the power acting at the end of the lever (g), will have most influence when exerted at right angles to it in the line (g, e), but as this cannot be accomplished in a gate where the power must be applied obliquely, it follows, that a large angle becomes requisite; that the greater the angle, the greater the power, or in other words, the less the strain on the construction of the gate, or the less the tendency to sink at the head. The half of the right angle (c, e, g) seems a reasonable limit, by which, if the power requisite to hold the weight in equilibrium, when acting at a right angle, be as the side of a square of the length of the lower bar of the gate (g, c), then the power requisite to effect the same end, when acting at an angle of 45 degrees, is as the diagonal to this square (g, h. By changing the square to a parallelogram, the relative proportions will still be the same, and the advantages and disadvantages will be rendered more obvious.

2854. Parker's compensation hinge for gates which are much in use (fig. 397.), is an

397

a

excellent corrective to their falling; all that is necessary when the gate sinks at the head is to screw it up by the nut (a), till it regains its original position. For road and farm yard gates the hinges are valuable parts of the construction.

2855. A gate should be so hung as to have two falls; one to the hanging post, to make it catch, and the other to a point at a right angle with the gateway, so as to keep it fully open. To effect this purpose, having set the post perpendicular, let a plumb-line be drawn upon it: on this line, at a proper height, place the hook, so that it may project three inches and a half from the face of the post; and at a convenient distance below this place the lower hook an inch and a half to one side of the perpendicular line, and projecting two inches from the face of the post; then place the top loop or eye two inches from the face of the hanging style, and the bottom loop three inches and a half: thus hung, the gate will have a tendency to shut in every position. A gate so hung will have a tendency to shut in every position; because if the weight of the gate be represented by a diagonal line from the heel to the head, this, by the resolution of forces, is resolvable into other two lines; one perpendicular, and the other horizontal; the former representing that part of the weight which presses in a perpendicular position, and the latter that part of the weight which presses in a horizontal direction, and gives the gate a tendency to shut. (Northumb. Rep. 63.)

2856. Gates are generally constructed of timber, and whatever kind may be used, it is essential that it be well seasoned, as without attention in this respect, they are soon deranged in their structure by the heat of the sun : they should also be well and correctly put together. Oak is undoubtedly the best sort of wood for the purpose, where durability is the object; though some of the lighter kind of woods, as deal, willow, &c. will often last a great length of time, as, from their lightness, they are not so apt to destroy themselves. The lighter gates are made towards the head or opening part the better,

provided they be sufficiently strong for the purpose they are to serve; and on this account the top bars may, in many cases, as where horses are to be kept, be left considerably stronger than the others. If this be not done, they are liable to be broken by the animals rubbing their necks upon them, except where they are made very high. Gates are generally made eight and an half or nine feet in width, and from five to six feet in height; the bars being three or four feet broad, and five or six in number. In particular instances a smaller bar is introduced between the two lowermost ones, in order to prevent small animals getting through.

2857. Iron, both hammered and cast metal, has long been in use for ornamental gates (fig. 398.), and has lately come into use in some districts for field gates. Their eligibility

898

must depend on their price and durability relatively to wood. At the ordinary prices of wrought iron and oak, they will be found of doubtful economy; cast iron gates are too heavy, and too liable to be broken, for agricultural purposes.

2858. The posts or pillars to which gates are attached should, in all convenient cases, be formed of stone; as this material, when hewn and properly constructed, will last for ages. When formed of wood, oak or larch are the best sorts. The latter, where suitable, should be used without removing the bark, which has been found to add greatly to their durability. In some places it is customary to plant trees for gate-posts, and after they have attained a certain size and thickness, to cut them over about ten feet above the surface: where the trees thrive, they form the most durable of all gate-posts; in many instances, however, they misgive, and much trouble is necessary to repair the defect. Where the posts are made of dead timber, they should always be strong, and the wood well prepared; that part which is let into the earth should also be defended, by dipping it in coarse oil, or giving it a coat of pyrolignous liquor; and all that is above ground exposed to the action of the weather, should be well covered with one or two good coats of oil-paint. The expense of this preparation is but trifling, while the benefit is very great.

2859. The substance of a gate-post, according to Parker, should be from eight to ten inches square, or, for very heavy gates, a foot square would not be too large. If made of still larger size, it is better. And he says, that the steadiness of a gate-post depends, in a great measure, upon the depth to which it is set in the ground, which ought to be nearly equal to the height of it. Five or six feet is, in general, fully sufficient. But the posts may be kept in their places by a strong frame-work placed under the ground, extending between the posts.

399

b

2860. The fastenings of gates, it is observed by Parker (Essay, &c. 1816.), are as various as the blacksmiths who construct them: the subject occupied his attention in connection with the hanging of gates, and he has introduced various improved forms. One of the most secure (fig. 399.), is a spring-latch (a), opened by a lever (b), which works in a groove of the upper bar of the gate, and therefore cannot be rubbed open by cattle, while, by means of a knob at the end of the lever, and rising up against the top of the upright bar (c), so that cattle cannot touch it, it is very easily opened by persons on horseback with or without a stick or whip. 2861. A simple, economical, and effective spring-latch consists of a bolt (fig. 400 a.), which is loose, and plays freely, in two mortised openings in the upright bars, and is kept in place by a spring (b). The gate may be shut from either side, when the bar, striking against the projection (c) on the falling post is pushed back, till, arriving at the mortise (e), the spring (b) forces it in, and the gate is shut securely. Such a gate is easily opened by a rider. This is a good latch for the common field gates of a farm.

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2862. For gates of an ornamental kind, Parker says, he does not know a better latch than the crooked lever (fig. 401.) now in common use.

2863. Gates are of different kinds (figs. 402. and 403.), according to the particular custom of the district; but the principal sorts made use of are the swing-gate, the folding-gate, the slip-bar gate, and the wicket and turn-about gate.

401

402

403

2864. The improved swing-gate of the northern counties is well adapted for agricultural purposes. There is a projection on the fore-part of the hanging-style, which rises nine inches, and on which the lower end of the diagonal bar, passing upwards, rests; there is also a diagonal bar through which the three middle horizontal bars pass. It is found to be a very strong and durable gate.

2865. In Parker's improved swing-gate, the diagonal bar rising from the low er part of the heel of the gate meets the middle of the rail, and the two upright bars are placed at proper distances between the middle and the head of the gate: these cross-bars must, he thinks, assist very much in keeping the gate together; but what is most to be guarded against is, its sinking at the head, and to prevent which, this gate (he says) is well contrived.

2866. The tressel-bar gate (fig. 404.) consists of two bars, one hung by a few links to each gate-post, and in the middle of the opening, where the bars meet, they are supported by two legs like a tressel, and may be padlocked, or fastened by a pin and a few links, &c. In the promenade at Florence such gates are made use· of to close the larger carriage openings.

404

AA

The

2867. The slip-bar gate is, perhaps, the most durable of any, especially where the gate-posts are of stone, with proper openings left for the reception of the bars. only objection that can possibly be made to the slip-bar gate is, the trouble of opening and shutting; which, when servants or others are passing through it, in a hurry, occasions its being frequently left open. In other respects, it is preferable to every other description of gate, both in the original cost, and greater durability. It is to be noticed, however, that upon the verge of a farm or estate, especially where it is bounded by a high road, the slip-bar gate will not answer, as it does not admit of being locked, or secured in the same way as other gates; but in the interior of a farm or estate, it will be found the cheapest sort of gate.

2868. The chained slip-bar gate, though more expensive, is not liable to the same objections as the last. Here the bars are connected by a chain down the middle of the gate, and, therefore, if one bar is padlocked to the post, none of them can be moved till that one is unlocked.

2869. The turn about, or wicket-gate, is only used in cases where there is a necessity for leaving an entry for the people employed to pass backwards and forwards. This purpose they answer very well, and at the same time keep the field completely enclosed, as they require no trouble to shut them in the time of passing.

2870. Styles are contrivances for man to pass over or through fences, without the risk of even permitting the larger quadrupeds to accompany or follow him. There are many forms perfectly well known every where; as by steps over a wall; by a zig-zag passage, formed by stakes, through a hedge or paling; a turning-bar or turnstyle, &c.

2871. The style of falling bars (fig. 405.) is chiefly used in pleasure-grounds, or be

405

tween paddocks: it consists of bars light at one end (a), and heavy at the other (b), with concealed joints or pivots, in an upright post (c), placed nearer one end of the bars than the other. Then, while the weight of the short ends of the bars keeps them in a fencible position, a slight pressure on the other end will form a passage (d), which any one may easily step across.

2872. Bridges are frequently required on estates and farms for crossing ditches and water-courses. They are generally large stone conduits or barrel-drains; or in the case of large streams, arches of masonry. In the case of small drains, wooden pipes or boarded tubes are sometimes resorted to, and even earthen pipes have been used; but masonry should always have the preference.

2873. The double or folding-gate (fig. 406.), is considered by some to be much more

406

durable than

those of the

swing kind; be

cause the bars,
from being only

half the length, render the joints of the gate not so liable to be broken, or the hinges to be hurt by straining. On the other hand, such gates require more time and attention in the opening and shutting, and the latter operation is troublesome to perform, when both halves have fallen at the head. These gates are not, therefore, in such general use in agriculture as the swing kind; but they are common as gates to parks, and other scenes of dignity and ornament.

2874. Clarke's window-sash gate (fig. 407.) is a recent invention,

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which may be of use in some cases, especially in farm-yards. It is suspended by two weights, and opens and shuts exactly on the principle of the window-sash. The weights may be of stone or cast-iron, and the pulleys are of iron, and nine inches diameter. It was applied in the first instance to a cattle-court; but has since been

408

erected in different situations. Its advantages the inventor considers to be the following: It is easy to open (b), or shut (a); remains in whatever situation it is placed; is not liable to be beat to pieces by the action of the wind; shuts always perfectly close, whatever be the height of the straw or dung in the court or gate-way; a cart may be driven quite close on either side before opening; is perfectly out of the way when fully open, and not liable to shut on what is passing; the gate bottom not liable to decay by being immersed in the dung, as is commonly the case with cattle-court gates; not liable to go out of order; may be erected in a hollow place, where a swinging-gate could not open either outwardly or inwardly; and is likely to be more durable than ordinary gates. A small gate of this description (fig. 408.) is said, by Lasteyrie (Col. de Machines &c.), to have been long in use by the Dutch.

BOOK V.

OF THE OPERATIONS OF AGRICULTURE.

2875. The operations of agriculture are effected under the direction of man, and by means of the mechanical agents, or implements and buildings which we have passed in review in the preceding book. They are either made directly on plants or animals, which may be considered the objects of agriculture; or on the soil and climate, which are the natural agents of growth and culture. They may be arranged as manual labors and operations, operations with beasts of labor, and mixed operations.

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