252 



THE FARMER'S MAGAZINE. 



ON TRUNK-DRAINING, 



A trunk is the body without the head and limbs, the 

 tnain stem without branches and ramifications. It is 

 the chief part of an ory;anized growtli, tlie foundation 

 of an artificial structure, and the base of any opera- 

 tions : it forms the support on which any structure 

 rests, from which it receives the formation, the exist- 

 ence, and its value. The trunk is the largest member 

 of any production, and the body of any con^rrgation of 

 parts : the use of it receives the adhesion of other parts, 

 and renders to them its own assistance. 



By trunk-draining are understood the water courses 

 that receive and convey the discharges of water from 

 the small drains, which intersect and ramify any entire 

 superficcs of ground, and under the general designa- 

 tion are comprehended rivers, brooks, rivulets, arti- 

 ficial open cuts, and tlie large covered drains that are 

 placed along jJie lower end of fields and lands for the 

 purpose of carrying the water from the under drains. 

 These conveyances perform the same offices with the 

 body of a man, and the trunk of a tree : they com- 

 municate with the branches, and uphold the existence 

 by administering support and relief. The functional 

 parts of organized bodies would be surcharged and 

 suffocated with excrements and exudations if the vent 

 by the trunk was not provided to relieve the super- 

 fluities that are cast off. The voidances find an egress 

 by which to discharge the dregsof the process of ela- 

 boration. The small drains, of the brandies of the 

 performance, collect the water from the land, and find 

 by the trunk an exit by which the water is relieved, 

 and their function progresses without stop or interrup- 

 tion. The connection of the small drains with the 

 trunk must be intimate and free in the action. The 

 latter must be ready and sufficient to receive and convey 

 the discharge of the small drains, in order that the 

 utility be not impeded, nor the operation disturbed. 

 Nature has shown the essential purpose of a trunk, or 

 principal stem in all its organized productions; the 

 bole of the tree supports the ramifications and the 

 foliage ; the stem of the herb upholds the stalks of the 

 leaves, and the fruit, and the universal provision in all 

 cases exhibits a base or support for every composite 

 erection. The inorganic world is similarly composed : 

 the river receives and conveys the w^ers of the smaller 

 streams, and discharges the whole contents into the 

 general reservoir of the sea ; the rivulets receive the 

 ■washings of the surface of the ground, and the harder 

 materials of the globe are seen ^to uphold the softer, 

 not only as a base on^hich to rest, but as a source 

 from which to draw the reservation and increase of 

 the composition. Without a trunk, main support, or 

 principal stem, no production or operation can be le- 

 gitimately entertained or executed. 



A river being the discharge of collected waters 

 into the general reservoir of the sea, is the trunk which 

 relieves all the subordinate agents of the burden in- 

 curred by the discharge of the functions of office. The 

 bed of rivers is naturally in low grounds in which the 

 waters have scooped a channel that is very considerably 

 lower than the surrounding surfaces. The fall towards 

 the sea of all countries affords a descent for the waters, 

 that is more or less rapid according to the declivity 

 of the surface, and the obstacles that are encountered. 

 In most cases, the descent of rivers constitutes a con- 

 veying trunk for the collected waters that effectually 

 relieves the smaller collections, and affords a ready 

 outlet to the contributions. Low grounds and alluvial 



flats are the only occurrences which may be insuffi- 

 ciently accommodated by the trunk of the river as a 

 conveying channel for the collected waters of the sur- 

 face of the ground; heavy falls of rain will flood the 

 river, and cause an overflow of the water above the 

 banks, and over the adjoining grounds ; during which 

 time the discharge will be stopped of the conductors of 

 water into the river. To keep the river within the 

 banks, and prevent the overflow of water on the lands, 

 grassy mounds of earth are raised along the course of 

 the river, in a line back from the water's edge, so as to 

 allow ample room for the increase of flooded waters 

 without unduly confining the stream to compel a vio- 

 lent breach of the embankment. During the time of 

 low waters the descent will be sufficient for the escape 

 of the waters that are discharged : during floods the 

 escape will be stopped, and a reflux of the waters will 

 stagnate into any opening or hollow that can be found. 

 It is this effect that has to be guarded against on low 

 grounds over which the waters flow, and in several cases 

 the difficulty is not small of remedying the evil. A 

 floodgate may be placed in the opening of the embank- 

 ment, through which the water is dischai'ged into the 

 river, which will be shut by the outside pressure of the 

 swollen river, andhinder the reflux of any water behind 

 the embankment. But the usual discharge of water 

 will be prohibited from making its escape, and will 

 stagnate and overflow if it has not room for expansion. 

 This stagnation, by flowing backwards, will hinder the 

 usual discharges of the smaller contributions, impede 

 the action, and inflict damage, until the decrease of the 

 swollen rivers, by lessening the outside pressure on the 

 flood-gate, enables the water collected in the inside to 

 force it open, and find a discharge. This plan is some- 

 times the only adoption that can be used, circumstances 

 prohibiting other recourse ; and the attendant evils 

 must be borne. The collections of water that join the 

 flat course of the river should be led into it at the 

 sharpest possible angle of divergence, so that, when it 

 joins the chief current, no backward pressure is felt, 

 \)ut a willing reception is found into the general move- 

 fiient in one and the same direction. In many cases this 

 direction may be impossible ; but, whenever in any way 

 to be attained, the advantages of it are very large. 

 During the time the river is flooded, the damage done 

 by the water itself would not be of much moment ; 

 but earthy solutions are held in suspension by the col- 

 lected waters of the country, and, being stagnated and 

 introduced backwards into the smaller drains, a sedi- 

 ment is deposited which the weak discharge from the 

 small drains is unable to remove, and it becomes firm 

 ground, and fills up the drain. It is even forced up- 

 wards among the filling materials of the drains, leaves 

 an earthy residuum, which remains and impedes the 

 reception of the surface-water. The largest open cuts 

 cannot prevent this consequence, as the extent of ca- 

 pacity will be overpowered by the body of waters. 

 Much ground will also be occupied by many of these 

 excavations, which should be confined to one main 

 leading cut that remains uncovered. The conveying 

 direction of this cut along the stream of the river, and 

 joining it at a very sharp angle, will best serve the pur- 

 l)0se, if at all available. Flood-gates are liable to the 

 heavy objection of congregated waters inside the em- 

 bankments, which remain during the time of the 

 floods, and inflict damage. When a very slanting 

 direction is effected, the backward power of the water 



