772 PRACTICE OF AGRICULTURE. Part III. 



live, will be more productive in a wet climate than in a dry one. Hence, in the western coasts of England, 

 as in Lancashire, where the quantity of rain that falls annually varies from forty to sixty inches, a siliceous 

 sandy soil is much more productive than the same species of soil in the eastern districts, where seldom 

 more than from twenty-five to thirty-five inches of rain fall in a year. In wet climates, also, even wheat 

 and beans will require a less coherent and absorbent soil than in drier situations. At the same time, 

 weather moderately dry is the most favourable to a great produce of corn; and the blossoms of wheat, in 

 particular, set best if no rain falls in the flowering season. 



4726. The importance of moisture to vegetation is obvious to every one. Water constitutes a large pro- 

 portion of every plant, and is the vehicle of the food of plants held in solution. Hence, without so essential 

 an ingredient, they must either become stunted in their growth or perish. In dry weather, when vege- 

 tation seems at a stand, no sooner do showers of rain fall, than a rapid growth of every kind of herbage 

 immediately succeeds, even on poor dry soils, where otherwise, however well manured, vegetation would 

 make but slow progress. 



4727. The quantity of rain that falls annually in any country is a very inferior consideration, when 

 compared with that of the general and equable distribution of that quantity throughout the several days 

 and months of the year. A great quantity, at the same time, is rather hurtful than beneficial ; whereas 

 those moderate, but golden showers, which regularly fall on a soil calculated to receive them, are real 

 sources of fertility. It is by this that the character of a climate, whether wet or dry, is chiefly deter, 

 mined, and the operations of agriculture are principally influenced. 



4728. The utility of a moist atmosphere, with a view to vegetation, is, in some respects, peculiarly re- 

 markable. Thus, in wet climates, as on the western coasts of England, Scotland, and Ireland, crops of 

 grain and potatoes are found to exhaust ihe soil less than in dry situations. Oats in particular are im- 

 poverishing in a greater degree in dry climates, than in moist ones ; and in the former, should be sown 

 much earlier than in the latter. 



4729. The disadvantages of a ivet clitnate to a far?ner, more especially if accompanied with a retentive 

 soil, are very great. It is calculated, that in the richest district in Scotland, the Carse of Gowrie, there 

 are only about twenty weeks in the year fit for ploughing; whereas in several parts of England, they 

 have thirty weeks, and in many cases more, during which this essential operation can be performed. 

 Hence ploughing must be much more expensive in the one case than in the other. 



4730. The season of the year in which rain abounds is likewise of much importance. An excess is pre- 

 judicial in any season, but is peculiarly so in autumn, when it often lodges the grain by its violence, or by 

 its long continuance prevents the corn from being properly harvested. The hopes of the husbandman 

 are thus blasted, and the fruits of his toil and industry are frequently diminished, and sometimes entirely 

 lost. 



4731. Detffs have a great effect in furnishing plants with moisture ; and, indeed, without their aid, 

 vegetation, in warm and dry climates, could not go on. Even in temperate regions dews are beneficial. 

 In Guernsey, on the coast of Normandy, the autumnal dews are singularly heavy, so much so that, in the 

 middle of a hot day, the dew-drops are not quite exhaled from the grass. From this moisture the after- 

 grass receives great benefit. Dr. Hales estimated the quantity of dew that falls in one year at three and 

 a half inches ; Dalton, at nearly five inches. In this matter, however, it is not easy to be correct. 



4732. The prevailing winds have a great influence on the character of a climate, and a powerful effect 

 on vegetation. When they pass over a large expanse of water, they are usually of a warmer or higher 

 temperature in winter, than those which blow over high lands; more especially if sucli come from 

 countries covered with snow. Hence the east and north-east winds, which have passed over the coldest 

 regions of Europe, are much colder than the west and south-west winds, which blow over the Atlantic 

 Ocean, and they oftener occasion blights. The former are comparatively drier, unless when accompanied' 

 by those thick mists, called haars, arising from the copious evaporation of the German Ocean. The latter 

 are loaded with the vapours of the Atlantic, and often, from excess of moisture, are rendered prejudicial. 

 The strength of the prevailing winds, or the violence with which they act, more especially during harvest, 

 ought likewise to be considered. If they are very violent, they are apt to affect the crops, and of course 

 it becomes an object to suit the produce to them ; and to form fences, enclosures, and plantations accord- 

 ingly. 



4733. A maritime position occasions a more equal temperature in a climate. Where a great body of land 

 is exposed to the heating rays of the sun, the air becomes much warmer than it would if resting upon a 

 small body of land, contiguous to, or surrounded by, the ocean. On the other hand, as the sea always 

 preserves nearly the same temperature, and, except in the most northern regions, is never frozen, it com- 

 municates warmth, in the cold seasons of the year, to the air passing over it, which had been cooled in its 

 passage over continents covered with ice and snow. Hence islands are more temperate than continents. 

 It appears, indeed, that the thermometer has not so great a range on the sea coast, as in the more inland 

 parts of Great Britain, even at an elevation of 400 feet above the level of the sea. Of the influence of 

 proximity to the sea many proofs might be brought forward. It is in consequence of this circumstance, 

 that the city of Moscow, which is situated somewhat farther south than Edinburgh, experiences winters 

 much more severe. Another effect of a maritime position is, that strong winds which blow from the sea 

 are sometimes accompanied by salt spray or vapour, which is injurious to crops of grain, and the leaves of 

 trees ; but when it comes in moderation, those saline particles, with which the westerly winds are loaded, 

 contribute to the verdure of the fields in pasture. 



4734. The nature of the inland position is also of much importance. The relative position of the neigh- 

 bouring hills occasions a material difference of climate, exposing some districts to great severity of weather, 

 and, by protecting others from that disadvantage, greatly promoting their fertility. 



4735. In many countries the seasons are regular. In others, as in Great Britain, they are extremely 

 variable, and often change, in the space of a few hours, from dry to moist, from hot to cold, from clear to 

 cloudy, and from a pleasant serenity to all the violence of a tempest. But such irregularities of climate, 

 however uncomfortable, are often favourable to vegetation, and compensated by the advantages they pro- 

 duce. It is not in countries where the seasons of heat and cold, wind and rain, are periodical, or where 

 the greatest regularity of climate takes place, that mankind are the most healthy or vigorous, or the useful 

 productions of the soil most perfect. Perhaps a sameness of climate, as well as of other things, is prejudi- 

 cial rather than useful. Where a climate is inconstant, the air is refined and purified by the frequent 

 changes it undergoes ; and the disadvantages which originate from that source are often counteracted, 

 or at least essentially mitigated, by judicious management, and persevering exertions. 



4736. The climate of a country is likewise affected by atmospherical and natural phenomena ; by earth- 

 quakes, volcanos, violent thunder storms, lightning, hail storms in summer, early frosts, whirlwinds 

 and hurricanes, water-spouts, and by that atmospheric appearance, known under the name of the 

 aurora borealis, so frequently to be seen in northern, and sometimes even in southern, regions ; but these 

 phenomena, for the most part only occasional, sometimes prevent greater calamities, and, in this country, 

 are rarely attended with permanent evils. 



4737. Frosts late in spring are highly injurious to the blossoms of fruit trees ; and autumnal frosts creep 

 along the banks of rivers, destroying the corn in the flowering season, and blasting the stems of potatoes 

 in low situations. Winter frosts are ultimately rather favourable to vegetation ; and snow, particularly 

 when it covers the ground for some time, and gradually melts away. 



4738. The size, and, in many cases, the value, of the productions of a country, depend upon its climate, by 

 whose influence their growth may either be advanced or retarded. The same species of tree, which, in a 

 temperate climate, will rise to a great height, and swell to an immense size, in an exposed situation will 

 remain small and stunted. By a favourable climate, also, the most barren spots, which in a cold country 



