DRAINING. 



67 



Draining, portion of water between them, the pressure on the 

 ^""Y"""' exterior one is diminished. A good instance may be 

 seen at Lossiemouth, in Morayshire, upon the great 

 cut which has drained the Loch of Spynie. Many 

 other precautions are requisite for the security of these 

 sluices ; but we cannot particularise them here. When 

 there is no natural outfall, the waters are lifted over the 

 bank by machinery of various descriptions. The 

 marsh-mill of the eastern fens, is a windmill, having a 

 iLU. body of brick about 20 feet high. The axle of the 



sails, by two bevel wheels, communicate motion to an 

 upright shaft, on the lower end of which a horizontal 

 wheel moves another vertical wheel ; on the outer end 

 of the axis of this last, is a small water wheel, similar 

 to that of an undershot mill, working in a case of wood 

 or stone, and with a valve drain at the head ; the lit- 

 tle water wheel is thus driven against the fall, and 

 throws up the water three or four feet, which permits 

 its escape into the river. 



When a fall of water can be had, a very simple 

 mar-h mill is formed by two water wheels, on one axle 

 of which one is driven by the fall of water, and the 

 other acts as usual, in lifting the water over the bunk. 

 The current of the river is sometimes used as the moving 

 power : though this is not advisable, great benefit 

 may, however, in many cases, be derived from the rise 

 and fall of the tide. If the drains fall freely into the 

 brook, the brook into the river, and that into the ea, 

 nothing further need be wished for ; but it often hap- 

 pens that one or other of these is so obstructed, as to 

 cause injury to the lands above. The new channel, 

 or operations for the amendment of the old, must be 

 frequently executed on property which has no imme- 

 diate prospect of advantage from the undertaking. 

 Hence it becomes necessary to have legal authority for 

 this purpose, and to form commissions of drainage, which, 

 in order to do their business with effect, should have 

 cognisance of the entire river or district, and of all the 

 baron of land which is drained thereby; and they should 

 have power to assess individuals or communities, ac- 

 cording to the benefit received by the improvements 

 which they effect. 



Romney Marsh is governed by 24 jurats and a com- 

 mon bailiff. If any person should refuse or neglect to 

 make necessary repairs, the bailiff does them at the 

 oversight of the jurats, and charges double on the de- 

 faulter ; the surplus goes to the fund for banks and re- 

 pairs ; the defaulter may be distrained for the same 

 within the marsh. 35 Ed. III. Forty shillings per acre 

 is the price paid for land taken for banks, ditches, and 

 water gangs. 3~> Ed. III. The bailiff and jurats were 

 incorporated by Edward IV. 



In a session of Sewers at Ilford, in Essex, 19th April 

 1639, an order is recited for raising L 1706, to repair a 

 breach in the banks at Bromley ; and upon the neglect 

 of certain persons to pay their quota, a lease for 4-1 

 years is made of several parcels of land belonging to 

 them, unto others at a pepper corn rent. Papers in 

 retli/ ling Office. 



When,- any person, assessed by commissioners of 

 eewers to any lot, and refuse or neglect to pay the land 

 to be leased, or passed in fee simple, to recompence the 

 undertaker. 13 Eliz. cap. ix. 



CHAP. II. Of Subsoil Draining. 



Su(<soil It is not enough to discharge useless waters from the 



draining. gur f ace o f the land, we must also remove them from 



the plant bearing soil, if we wish it to produce any 



other tlian useless aquatics. In retentive bottoms, this 



is effected by drains in the subsoil or stratum, imme- Draining. 



diately beneath the action of the plough ; but as a de- 



feet of moisture is equally injurious to agriculture, we 



shall, under this head, give a view of the distempera- 



ture of soils in general, with respect to moisture, and 



suggest what appears to us the most probable means of 



correction. 



By the soil, we understand that stratum, which form- 

 ing the upper covering of the land, affords support 

 and nourishment to the various vegetables, and is stir- 

 red and exposed to the sun and air by the operations 

 of agriculture. The thickness of this stratum, or depth 

 of the soil, is very various ; but in general it either al- 

 ready does, or by proper management may be made to, 

 extend to the depth of nine inches. 



Soils vary greatly in quality, and are seldom com- Djff ercnt 

 posed of any single substance : but with respect to kinds of 

 drainage, they may be all arranged into two classes, viz. soils. 

 the impervious, commonly called heavy or strong 

 soils ; and the porous, termed light or weak soils. Of 

 the former kind are clay, or the substances combined 

 with it, as clayey loams. Clayey gravels, &c. black 

 peat earth also, before cultivation, is of this kind. Of 

 the latter are sandy, gravelly, or other light loams, 

 peat earth before cultivation, stone brash lands, &c. 

 The subsoil is the stratum which lies immediately be- 

 neath the former, and may be supposed to extend from 

 nine inches, or the distance to which the operations 

 of agriculture extend, to about 2 feet, or the depth to 

 which drains are usually sunk, when intended to be 

 covered and passed over with the plough. The limits 

 of this however, like the former, are very variable ; 

 since, in many cases, uniformity of structure prevails 

 to a great depth, while in others the soil lies immedi- 

 ately over rock, and may be said to possess no subsoil 

 at all. 



The influence of the weather, the agency of manures, 

 and the residence of the various plants and animals 

 that inhabit the soil, are confined to the upper stratum. 

 The subsoil therefore chiefly demands attention, by its 

 effects in regulating the supply of moisture. If exces- 

 sively porous and dry, the soil above it is liable to be 

 parched, and becomes unfit for the existence of plants. 

 If porous and wet, the health of the plants above it is 

 injured, or they give place to the ranker aquatics. If 

 the subsoil be impervious, similar consequences take 

 place, according to the weather ; but if the subsoil be 

 open to a sufficient depth, the water winch filtrates 

 through the soil, or which rises from the bottom, will 

 be there earned off without injury to vegetation ; while,, 

 on the other hand, a reservoir of moisture will be with- 

 in reach of the roots, in the event of long continued 

 droughts acting upon a light soil, and depriving the ve- 

 getables of their usual supply. 



When there is land which nature has not already pro- 

 vided with this necessary stratum, it is the business of 

 man to supply it The substrata must be opened or 

 closed as the case requires, until the water remain at a 

 due distance from the vegetable mould. The distance 

 depends on the quality of -the subsoil and bottom ; for 

 loams will hold the water much higher than sand, and 

 that again higher than gravel, owing to the greater 

 capillary attraction of the smaller pores. The supply 

 which is furnished or abstracted by the bottom, depends 

 partly on its position, and partly on the specific com- 

 position of the strata. 



The bottom or base of land is under the subsoil, com- 

 prehending every thing below the common operations 

 of culture and drainage. It is the seat of springs, form-- 



