504 



SCIENCE OF AGRICULTURE. 



Part II. 



tend to regain that perpendicular position in which alone it is in a state of equilibrium. The upper hinge 

 should, therefore, be placed on the highest bar of the gate. The distance between the centres of the two 

 cylindrical knobs of iron (on d) may be 5 inches, which will be found sufficient to give a strong impetus 

 to the gate to shut itself. The power of a gate to shut itself, in all cases, is a certain advantage, even 

 where fields are in a course of constant cultivation, and a very obvious advantage where they are kept 

 chiefly in grass. There is no providing, in ordinary cases, against the carelessness of persons, who will 

 rather leave a gate open than undergo the little labour required to shut it. There is an apparent ob- 

 jection, indeed, to this species of gate, which is, that each time a cart or waggon passes, the gate must 

 not only be opened, but held open until the carriage has passed. The inconvenience, however, from this 

 is not sogreat in practice as might be supposed. It is very rare that farm horses will not obey t!ie voice of 

 the driver, and pass while he holds the gate open with his hand. Where the gate must be kept constantly 

 open, as when there is a leading of corn or hay from the ficM, or of manure to it^ it can either be propped 

 back by a stone, or removed from the hinges, and laid aside till wanted ; or ill inconvenience of this 

 nature may be obviated effectually, by sinking a stone in the ground, and fixing to it a simple hook or 

 latch, to which the gate may be attached when opened. 



3098:^jrheJatc/ipf.agnteofthiskind must be made to open with as little force as possible. To this end, 

 the spring (e), two feet in length, is fixed nearly at right .angles to the piece of iron (/), which passes 

 through -the-'head of th6 g^te, and is attached to the handle by a joint or hinge fixed to the handle (g), 

 while th hajdte iteelf i, ^ftached to the back of the head by a similar joint. The notch in the hori- 

 zontal plate. Tor the reception of the spring, must be in the plane of a perpendicular from the upper 

 hinge." 



3099. The dimensions of this gate are as follow: "There are five horizontal, one diagonal, and four 

 upright bars. The hindmost of the latter, or, as it is generally called, the heel, is 4 inches by 3, 

 and the foremost, or head, 3 inches square. Into these are mortised the extremities of the hori- 

 zontal bars. The ujjrights, or braces, consist of pieces of plank nailed to one side of the gate, 3 

 inches by If. The diagonal, from the lower end of the head to the upper end of the heel, is of the same 

 dimensiofts, and is nailed to the opposite side of the gate. The heel rises a foot above the upper bar, 

 the other uprights 6 inches above it, and all of them project about 4 inches below the lower bar, which 

 again is 6 inches from the ground. The horizontal bars taper from the heel to the head, being 2% 

 inches square at their junction with the former, and 2} inches at their junction with the latter. They 

 may be bevelled a little at top. The length of the gate, including the breadth of the head and heel, 

 is 9 feet ; the height over the bars 3 feet 9 inches ; the distance between the heel and the pillar o inches; 

 and between the head and the pillar 3 inches. The plate for receiving the spring of the latch is 11 inches 

 in hprizontai breadth." , 



, 3100. T/ie best species of post or pillar " is a single stone of granite, greenstone, or any of the harder rocks. 

 In this case, instead of fixing the bands of the hinges into the stone, by running them in v/ith lead, they 

 ^hould be carried through to the opposite side, and fixed by a bolt or screw-nut. When wood is used for 

 ^o^its, any coarse kind, whether fir or hard wood, which is unfit for other useful purposes, may be employed. 

 Tbf the gate itself, the best Memel timber only should be used. Spruce is liable to break, and larch to 

 warp ; and Scotch pine, it is well known, when exposed to the weather, is one of the least durable of the 

 pine tribe. All the mortises of the gate, and the parts at which the uprights and diagonal cross the bars, 

 should be carefully coated with white lead ; and wh^n the parts of the gate are joined together, the whole 

 should afterwards receive two coats of paint. Gates of Memel wood, constructed on these principles, and 

 with these precautions, have been known to last for thirty years, without repair, or tending to trail upon 

 the ground. Expense in all 2l.ls." {Quar. Jour. Agr. vol. l p. 727.) 



3101. The tressei.bar gate {fig. 506.) consists of 

 two bars, one hung joy 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 car- 

 riage openings. ' 



3102. 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. The only objection that can possibly 



be made to the slip-bar gate i:s the troublebf open- 



ing anff'shutthig, w^|o^,\ when servants or others are passing through it in a nuirry, occasions its being 

 frequently left open. 'Iri 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 

 (S8ailtse'J>%ed}tflly where it is bounded by a high road, the slip-bar gate will not answer, as it does not 

 Jidmit of being locked or secured in the same way as other gates ; but in the interior of a farm ot estate, 

 it vipill be found the cheapest sort of gate. 



r .'310S. 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. 



3104. 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 it answers 



very well, and at the same time keeps the field completely enclosed, as it requires 



no trouble to shut it in the time of passing. 



3105. The double, or folding gate {fig. 507.), is considered by some to be much more 

 durable than those of the swing kind ; because 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 requii-e 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. 



&}G^Giarke's window-sash gate {fig. 508.) is a recent invention, 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 in diameter. It was applied in the first instance to a cattle-court; but has since been erected in 

 different situations. Its advantages the inventor considers to be the following : It is easy to open (6), or 

 shiit {a) ; remains in whatever situation it is placed ; is not liable to be beaten to pieces by the action of the 

 wind r shuts always perfectly close, whatever be the height of the straw or dung in the court or gateway ; 

 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. 509.) is said, by 

 I.,asteyrie {Col. de Machines, Sfc.) to have been long in use by the Dutch. 



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