Book V. ELEVATION OF FARMING LANDS. 711 



the winter be exhaled. By the water being retained in the upper soil, the putre- 

 factive process is interrupted, and manures are restrained from operating, conse- 

 quently the plants make but little progress. Hence, its grain is of inferior quality, 

 and when in grass, its herbage is coarse. 



4397. A stoney subsoil, when in a position approaching to the horizontal, is in general 

 prejudicial, and if the surface-soil be thin usually occasions barrenness, unless the rock 

 should be limestone, and then the soil, though thin, can easily be converted into healthy 

 pastures, and, in favorable seasons, will feed a heavy stock. They will also produce 

 good crops of corn, though subject to the wire-worm. 



4398. A porous subsoil is uniformly attended with this advantage, that by its means 

 all superfluous moisture may be absorbed. Below clay, and all the variety of loams, 

 an open subsoil is particularly desirable. It is favorable to all the operations of hus- 

 bandry ; it tends to correct the imperfections of too great a degree of absorbent power 

 in the soil above ; it promotes the beneficial effects of manures ; it contributes to the 

 preservation and growth of the seeds ; and ensures the future prosperity of the plants. 

 Hence it is, that a thinner soil, with a favorable subsoil, will produce better crops than a 

 more fertile one, incumbent on wet clay, or pn cold and non-absorbent rock. Lands 

 whose substratum consists of clean gravel or sand, can bear little sun, owing to their 

 not having the capacity of retaining moisture, and their generally possessing only a 

 shallow surface of vegetable mould. In England this soil was formerly called ri/e-land, 

 being more generally cropped with that species of grain than any other. When such 

 soils are cultivated for barley , they should be early and thick, with seed soaked forty- 

 eight hours in water, or in the exudation from a dung-heap. Thus its simultaneous 

 germination, and ripening at the same time, may be secured. 



Sect. IV. Of the Elevation of Lands relatively to Farming. 



4399. The elevation of lands above the level of the sea has a material influence on the 

 kind and quality of their produce. Land in the same parallel of latitude, other circum- 

 stances being nearly similar, is always more valuable in proportion to the comparative 

 lowness of its situation. 



4400. In the higher districts the herbage is less succulent and nourishing, and the re- 

 production slower when the land is in grass ; while the grain is less plump, runs more 

 to straw, is less perfectly ripened, and the harvest is also later when the produce is 

 corn. It has been calculated that in Great Britain sixty yards of elevation in the land 

 are equal to a degree of latitude; or, in other words, that sixty yards perpendicularly 

 higher, are, in respect of climate, equal to a degree more to the north. In considering 

 the crops to be raised in any particular farm, attention ought therefore to be paid to its 

 height above the level of the sea, as well as to its latitude. In latitude 54 and 55, an 

 elevation of 500 feet above that level is the greatest height at which wheat cart be cul- 

 tivated with any probable chance of profit ; and even there the grain will prove very 

 light, and will often be a month later in ripening than if sown at the foot of the hills. 



4401. The usual maximum of elevation may be reckoned between 600 and 800 feet 

 for the more common sorts of grain ; and in backward seasons the produce will be of 

 small value, and sometimes will yield nothing but straw. It is proper, at the same 

 time, to remark, that in the second class of mountains in the county of Wicklow, in Ire- 

 land, where no other grain is considered to be a safe crop, rye is cultivated with success. 

 Where the soil is calcareous, however, as on the Gloucestershire and Yorkshire wolds, 

 from the superior warmth of that species of soil, compared to cold clays or peat, barley- 

 grows in great perfection at an elevation of 800 feet above the level of the .sea. Some 

 experiments have been made to raise corn crops, at even a higher elevation, on the cele- 

 brated mountain Skiddaw, in Cumberland, but unsuccessfully. 



4402. The greatest height at which corn will grow, in the more remote parts of Scot- 

 land, so as to yield any profit to the husbandman, is stated to be at 500 feet above the 

 level of the sea. At the same time corn has been produced, in other districts of that 

 country, at still higher elevations, in particular at the following places : 



Feet above the Level Fett above ike Level 



of the Sect. qfthe Sea. 



Paiishof Hume, in Roxburghshire - 600 Doubruch, in Braemar, Aberdeenshire 1294' 



Upper Ward of Lanarkshire - - 760 Lead-hills, in Lanarkshire ^ . - 1564 



4403. These and other instaiices of land being cultivated on high elevations, however, are 

 merely small spots, richly manured, and, after all, producing nothing but crops of inferior 

 barley and oats, and seldom fully ripe or successfully harvested. It is only where the 

 soil is sandy or gravelly, that corn will at all answer in Scotland on such elevated situ- 

 ations ; and even then, only when the seasons are propitious, and when there are toe'al 

 advantages, favorable to warmth and shelter, in the situation of the )and.3. 



Zz 4 



