518 



FARMERS' REGfSTER 



[N(.. 9 



distinguishincp names of porous and impervious. 

 Sand, gravel, rock, and such calcareous earths as 

 are of an absorbent quality, from their open com- 

 position, are denominated porous. Clay, and cer- 

 tain kinds of (•■ravel, iiaving a proportion of ad- 

 hesive matter in their composition, which, binding 

 and cementing the particles together, render them 

 equally close and tenacious as clay ilself; with 

 such rock, as is of a solid and compact nalure and 

 without fissures, are the principal strata that resist 

 the admission of water, and are hence termed im- 

 pervious. It is evident, theretbre, that springs 

 must oriiTinate from water fallino' upon such porous 

 and absorbent surfaces, and subsiding downwards 

 till it is obstructed in its passage by these impene- 

 trable substances; li there forms reservoirs of con- 

 siderable mauifitude, which afterwards issue out 

 in all those ditierent appearances which are so 

 often met with. This is evident, from the observa- 

 tion, that rain fallini; on some parts of the ground 

 suddenly disappears, while it remains stairnant on 

 other still earned off by evaporation ; and from the 

 issue of springs beino; stronger in wet than in dry 

 seasons. Hence, after long continued rains, they 

 burst out in higher situations, and, as the weather 

 becomes drier, give over running out, unless at 

 their lovvest outlets. The strength of s[)rings also, 

 depends on tlie extentof high ground that receives 

 and retains the rain-water, which forms larwe re- 

 servoirs, and affords a more regular supply. Thus. 

 bog springs, or those that rise in valleys and low 

 situations, have a more copious and regular dis- 

 charge, than those which break out on high 

 ground, either on the sides, or near the summits of 

 hills. Abundant springs are never met with in 

 countries that are deeply covered with sand, nor 

 in those where the soil consists of clay to a great 

 depth. From the former cause, such is the case 

 in the sandy deserts of Arabia, and in the plains 

 of Lybia ; and from the predominant depth of clay 

 in the carses of Gowrie, Stirlini;. Clackmannan, 

 and others, springs are scarce, wells are often sunk 

 to a great depth, and the water of an impure 

 quality. Independent of the causes that have been 

 stated, as producing springs, there are certainly 

 other receptacles of water in the bowels of the 

 earth, to supply the many streams and rivers that 

 flow through it, the rains and dews that descend 

 being inadequate to that purpose ; but, as inquiry 

 into the nature of these would go beyond the depth 

 of this subject, what has already been explained 

 may suffice lor the present. 



A frequent cause of wetness is the stagnation of 

 water in the ditches that surround fields, particular- 

 ly in such as lie along the upper side of the in- 

 closure, where the water, being confined, finds its 

 way downwards into the open parts of the subsoil, 

 and oozes out to the surface, forming, in wet 

 weather, all the appearance of, and producing 

 nearly the same effect, as a natural spring. This 

 frequently happens where water is conveyed in an 

 open drain, or lead, or confined in a dam,* the land 

 lying adjacent to it, and lower, being always more 

 or less wet by that means. The remedy in these 

 cases, is simply the removal, or lowerins; of the 

 stagnant water, by giving more depth and declivi- 

 ty to the ditch or hollow in which it is conveyed or 



* Dam is the name used in Scotland for what is call- 

 ed, in the south, lead or race. Here, it means an arti- 

 ficial lake, pond, or collection of stagnant water. 



confined ; and, if in a lead, by making a cut on the 

 lower side, to intercept any water that may ooze 

 therefrom. 



Lakes, lochs, and stagnant water in hollows, are 

 often the cause of springs, and of wetness in ground 

 at a considerable distance from them ; and where 

 such are neither objects of pleasure nor use, they 

 ought to be drained. This will be further treated 

 ofj in the section allotted to that part of the subject. 



SECTION III. 



Of the various soils that require draining, lohether 

 injured by surface-water, or by that of springs. 



To enumerate all the various soils that require 

 draining, would be to mention every species of 

 earth composing the upper stratum of land ; as 

 every kind of soil is more or less liable to be wet 

 from particular circumstances in its formation, 

 when it comes in contact with water, eittier from 

 the clouds, or from the diflTerent kinds of springs, or 

 subjacent water by which it may be afl^ected. 



It is the object, however, of the present inquiry, 

 to describe only those that are most subject to 

 injury; and to explain shortly their nature and 

 texture, so far as tiiat knowledge is useful in guid- 

 ing the application of the proper drains which they 

 require. 



The particles of the various natural bodies that 

 are met with, being reduced by the successive in- 

 fluence of the atmosphere, and agency of other 

 causes; and being mixed together in diffii'rent 

 ways and proportions according to these operations, 

 constitute the compounds that form the bases of 

 soils in general ; while the materials of numerous 

 animal and vegetable substances, united with such, 

 compose the superficial mould, from which plants 

 in general derive their nourishment and support. 

 Thus, soils vary much in their composition, ac- 

 cording to the qualities and proportions, both of 

 the natural and artificial ingredients of which they 

 are formed, and also, according to the favorable 

 situation in which they may be placed. The im- 

 preonation of different matters, proceeding from 

 bodies considerably below the surface, has likewise 

 great influence in varying the properties of soils, 

 where no external appearances are perceptible by 

 which their qualities can be ascertained. Thus, 

 soils apparently dry and of good quality, that lie 

 at a considerable height above water, are often so 

 aflected by its influence, as to be kept cold and 

 moist, and, although they may have been drained 

 to a considerable depth beiow the surface, still 

 remain in a great measure unproductive. To 

 these the system ol' tapping particularly applies. 



Soils also, that exhibit every appearance of fer- 

 tility fi-om the nature of their composition, are often 

 so deficient in depth, and deposited on beds of cold 

 and wet clay, rock, or Avalery gravel, that they 

 are by no means so favorable to vegetation, as 

 others of an inferior quality, but thicker, and, lying 

 on a dry and kindly subsoil, are rendered more 

 fruitful and productive. The superficial appear- 

 ance of soils, and the natural plants which they 

 produce, may, in many instances, ascertain their 

 quality and texture ; but it is by chemical analysis 

 alone that these can with certainty be known. 

 This mode, however, can only be put in trial, by 

 those acquainted with chemistry; and as most 

 practical fanners are not conversant in that science, 

 and consider such experiments tedious and expen- 



