484 SCIENCE OF AGRICULTURE. Part II. 



of compromise must thus be made between the heights and hollows in the bottom of the ditch, though 

 the hne of thorn-bed must still be placed on the natural surface of the undulations, and will therefore 

 partake of their inequalities. When such a compromise is necessary, the superabundant earth thrown 

 out of the deep parts must be wheeled away to the shallow parts, to equalise the dimensions of the 

 hedge-bank. Should any hollow part be so deep as that the heights next it cannot possibly be cut 

 down so as to let the water flow away on either side, a drain must be made from the hollowest point 

 in the bottom of the ditch, down an inclining hollow or plain ground in the adjoining field, to some 

 ditch or drain already existing in it at a lower level. These undulations will cause another evil, that 

 is, the collection in their hollows of stagnant surface-water behind the hedge-banks. The only effectual 

 method of getting quit of this evil, and it is fortunately a simple one, is the building of drains under 

 the hedge-bed, opening into the ditch ; and whatever number of hollows there are, and almost however 

 small, there must be the same number of drains. As these drains must be formed completely under the 

 black mould, and at only a little elevation above the level of the bottom of the ditch, they can be 

 conveniently built only after the ditch has been entirely dug out ; and for this purpose, that part of the 

 hedge-bed which lies over these drains must be left undone till the drains are built, and finished afterwards. 

 A little taste and dexterity in the hedger, who should, of course, be a good spademan, will fill up these 

 gaps in the hedge-bank with neatness. If the hedge is to be planted along the side of a road, especially of 

 an ornamental road, and where a hollow in the road has been filled up to make the whole a continuous 

 level, the hedge-bed should also be brought up to the same level, with earth or turf, as may be most 



^go I expedient ; but still the thorn.plan'ts, here as 



_--> o eliewhere, must be laid among mould. The 



annexed figure (468.) will give an idea of 

 the work to be performed in such inequalities 

 of ground, and of the position of the drains: 

 it indicates the line of hedge-bed, with un. 

 dulations (a a) ; the top of hedge-bank paral. 

 lei to the bed [b b) ; the bottom of ditch (c c), 

 made to slope, to let the water run down 

 to the leading drain {e); and the small drains {ddd) under the hedge-bed, to convey away the surface- 

 water from behind the hedge-bank. 



3006. Marking off parallel lines of hedges. Thus one whole line of hedge may be planted, and all the 

 probable obstacles to its right accomplishment may be anticipated. Let us now surmount another 

 difficulty the marking off another line parallel to the first. Take the rule with the cross-head, and 

 measure from the thorn-bed already made, across its ditch, a distance so as to leave a scarcement of one 

 foot in breadth on the edge of the ditch, that is, in the present case, six feet from the thorn-bed. Any 

 distance from the hedge-bed will, of course, answer the purpose intended, but I have taken the above, 

 that the scarcement necessary for the preservation of the edge of the ditch might be indicated. Set off 

 other two such distances at about one hundred yards from each other, place poles in the three points, 

 and adjust their accuracy to one another. Make these measurements at such a place of the line of hedge, 

 as from it you may have a view of the places at which you wish to plant the new parallel line. Erect the 

 plane-table midway between two of the poles, and fix the eye-sights so as through them you may see one 

 of the poles in one direction, and the other two in another direction. This is the base line. Fix the 

 other eye-sights so as by looking through them you may see the place of the new line as clearly as the 

 field of vision will permit, and mark the angle of observation. This angle may be of any degree ; but the 

 nearer it is to the right angle, the more certainly will the breadth of the field be set off, so as to contain 

 its exact complement of ridges of a given breadth. Cause one of the men to fix a pole in the line of 

 observation where he will be most distinctly seen. Fix other poles along this line, so appropriately, that 

 how unequal soever the ground may be, the right line may be kept. From the stalk of the plane-table 

 measure by the chain, along the line of poles, the distance necessary for the proposed breadth of the 

 field. If your line of poles is at, or nearly at, right angles to the furrows of the ridges of the field, the 

 breadth of the field may be conveniently marked oft", so as to contain a given number of ridges of a given 

 breadth. It is necessary to attend to this, as a half ridge left at the side of the field would be inconvenient. 

 Fix this point by a pole. Remove then the plane-table to between the other two poles, the middle pole 

 being common to both stations ; adjust it to them without changing the relative positions of the eye-sights, 

 and, of course, the angle of observation ; and, in the same manner, measure another line from the stalk 

 of the plane-table, which will, of course, be parallel to the first across the field, of exactly the same length, 

 and mark it also with another pole. Fix a third pole at a specified distance, on the line passing through 

 these two last placed poles, and measure from it across the field to a point on the scarcement of the ditch, 

 at a distance from the stalk of the plane-table, where last placed, exactly corresponding to the specified 

 distance mentioned above; and if this third line, which may be considered as the line of proof by trial 

 and error, agree exactly with the length of the other two lines severally measured across the field, your 

 observations and operations have been correct. But, should the error be considerable, as of one yard, it 

 must be found out by another trial, and corrected. 



3007. Forming hedges in curved lines. All these observations apply to hedges in straight lines ; but 

 where irregularly curved lines are to be formed, they can be made by the poles above, but must be judged of 

 by the ej'e, so that a pleasing sweep may be rhade according to the nature of the ground, and which would 

 not oflfend the taste of the most fastidious, and the curves drawn conformably to the ploughing of the 

 adjoining land ; for if this latter consideration is not attended to, land may be lost for utility in tillage 

 in the depths of the curves. But poles set, in the first place, to guide the outlines of the sweeps, 

 and the spaces between them filled up by the cord distended over the hooked-headed pins, with curves 

 which please the eye, will generally accomplish all that can be done in this way, where geometrical curves 

 cannot be introduced. The rutting of the breadth of the ditch must follow the cord in its curved position, 

 and the sod for the thorn-bed must also take the sweep of the curves ; but great care is necessary in 

 making the curved sides of the ditch parallel to one another, for if the cross-headed rule is not held 

 at right angles to the line of the thorns, at whatever spot the measurement is taken, the breadth of the 

 ditch will vary considerably in difFerent places. There is no error into which the labourers will fall 

 more easily than into this, as they will most probably measure, without thinking of the consequences, 

 across the ditch at any angle ; and this is an error of such magnitude, that, if not rectified in time, 

 it will not only rob parts of the hedge-bank of some of its essential covering, but twist the ditch out 

 of the parallelism of its sides. 



3008. Season of planting. Thorns may be planted anytime from October to April, when the weather is 

 neither very frosty nor very wet. The autumnal season is upon the whole preferable, as the plants are 

 then ready to push forward in the earliest spring ; the months of January and February are also excellent 

 for the purpose, but in most seasons March and April are rather late, particularly in a dry soil, in which 

 young thorns suffer very much from drought. A southern and western aspect should always be preferred, 

 if possible, for thorn hedges. 



3009. Arguments for and against a scarcement. All the writers which I have perused on the planting 

 of hedges, recommend a scarcement of nine or ten inches in breadth to be left in front of the thorn 

 plants ; and Lord Kames, in The Gentleman Farmer, who is the most minute writer on the planting of 

 thorn hedges, though not nearly minute enough, gives a reason for doing this, which no other writer 

 condescends to do ; and his reason is, that it keeps the moisture about the thorns : and, indeed, he carries 

 his notions of the necessity of moisture to such a length, as to recommend the plants being placed parallel, 

 instead of square, to the ditch. At page 277, he says, " Instead of laying the thorns fronting the ditch, 

 would it not do better to lay them parallel to the ditch, covering the roots with three or four inches of the 



