690 PRACTICE OF AGRICULTURE. Part III. 



4211. With good private roads a farmer will perform his operations at much less expense ; the labour of 

 the horses will be much easier ; a greater quantity or weight of grain and other articles may be more ex- 

 peditiously carried over them ; manure can be more easily conveyed to the fields ; the harvest can be 

 carried on more rapidly ; and wear and tear of every description will be greatly reduced. {Code of Agri- 

 culture, p. 158.) 



BOOK III. 



OF IMPROVING THE CULTURABLE LANDS OF AN ESTATE. 



4212. Having completed the general arrangement of an estate, the next thing is to 

 improve the condition of that part of it destined to be let out to tenants, which, as already 

 observed, constitutes the chief source of income. The farm lands being enclosed and 

 subdivided, and the farmeries and cottages built in their proper situations, in many cases 

 no other improvements are wanted on the soil than such as are given by the tenant in 

 the ordinary course of culture. But there are also numerous cases, in which improve- 

 ments are required which could not be expected from an occupier having only a temporary 

 interest in his possession; and these form the present subject of discussion. Such 

 improvements are designated by agriculturists permanent, as conferring an increased 

 purchasable value on the property, in opposition to improvements by a temporary 

 occupier, the benefits of which are intended to be reaped during his lease. The latter 

 class of improvements includes fallows, liming, marling, manuring, improved rotations, 

 and others of greater expense, according to the length of lease, rent, and encouragement 

 given by the landlord ; the former, which we are now about to discuss, includes draining, 

 embanking, irrigating, bringing waste lands into cultivation, and improving the condition 

 of lands already in a state of culture. 



Chap. I. 

 Draining Watery Lands. 



4213. Draining is one of those means of improvement, respecting the utility of whicli 

 agriculturists are unanimous in opinion. Though practised by the Romans (143.), and 

 in all probability in some cases by the religious fraternities of the dark ages, it was not 

 till after the middle of the last century that its importance began to be fully understood 

 in Britain ; and that some individuals, and chiefly Dr. Anderson and Elkington, began 

 to practise it on new principles. About the same time, the study of geology became more 

 general, and this circumstance led to the establishment of the art on scientific principles. 

 The public attention was first excited by the practice of Elkington, a farmer and self- 

 taught professor of the art of draining in Warwickshire and the adjoining counties. On 

 the practice of this artist most of the future improvements have been founded ; and they 

 have been ably embodied in the account of his practice by Johnston, from whose work 

 we shall draw the principal materials of this section, borrowing also from the writings 

 of Dr. Anderson, Marshal, Smith, Farey, Stephens, and some others on the same 

 subject, and from the sixth and seventh volumes of the Highland Society^ s Transactions. 

 After submitting some general remarks on the natural causes of wetness in lands, we shall 

 consider in succession the drainage of boggy lands, hilly lands, mixed soils, retentive soils, 

 and mines and quarries ; and then the kinds of drains, and draining materials. 



Sect. I. Natural Causes of Wetness in Lands, and the general Theory of Draining. .. 



4214. The successful practice of draining in a great measure depends on a proper 

 "knowledge of the structure of the earth's upper crust, that is, of the various strata of which 

 it is composed, as well as of their relative degrees of porosity, or capability of admitting or 

 rejecting the passage of water through them, and likewise of the modes in which water is 

 formed, and conducted from the high or hilly situations to the low or level grounds. In 

 whatever way the hills or elevations that present themselves on the surface of the globe 

 were originally formed, it has been clearly shown, by sinking large pits, and digging 

 into them, that they are mostly composed of materials lying in a stratified order, and in 

 oblique or slanting directions downwards. Some of these strata, from their nature and 

 properties, are capable of admitting water to percolate or pass through them ; while others 

 do not allow it any passage, but force it to run or filtrate along their surfaces without 

 penetrating them in any degree, and in that way conduct it to the more level grounds 

 below. There it becomes obstructed or dammed up by meeting with impervious materials 

 of some kind or other, by which it is readily forced up into the superincumbent layers 

 where they liappen to be open and porous, soon rendering them too wet for the purposes 



