But, in some employments, the same quantity of industry will, in different years, produce very different quantities of commodities; while, in others, it will produce always the same, or very nearly the same. The same number of labourers in husbandry will, in different years, produce very different quantities of corn, wine, oil, hops, &c. But the same number of spinners or weavers will every year produce the same, or very nearly the same, quantity of linen and woollen cloth. It is only the average produce of the one species of industry which can be suited, in any respect, to the effectual demand; and as its actual produce is frequently much greater, and frequently much less, than its average produce, the quantity of the commodities brought to market will sometimes exceed a good deal, and sometimes fall short a good deal, of the effectual demand. Even though that demand, therefore, should continue always the same, their market price will be liable to great fluctuations, will sometimes fall a good deal below, and sometimes rise a good deal above, their natural price. In the other species of industry, the produce of equal quantities of labour being always the same, or very nearly the same, it can be more exactly suited to the effectual demand. While that demand continues the same, therefore, the market price of the commodities is likely to do so too, and to be either altogether, or as nearly as can be judged of, the same with the natural price. That the price of linen and woollen cloth is liable neither to such frequent, nor to such great variations, as the price of corn, every man's experience will inform him. The price of the one species of commodities varies only with the variations in the demand; that of the other varies not only with the variations in the demand, but with the much greater, and more frequent, variations in the quantity of what is brought to market, in order to supply that demand. The occasional and temporary fluctuations in the market price of any commodity fall chiefly upon those parts of its price which resolve themselves into wages and profit. That part which resolves itself into rent is less affected by them. A rent certain in money is not in the least affected by them, either in its rate or in its value. A rent which consists either in a certain proportion, or in a certain quantity, of the rude produce, is no doubt affected in its yearly value by all the occasional and temporary fluctuations in the market price of that rude produce; but it is seldom affected by them in its yearly rate. In settling the terms of the lease, the landlord and farmer endeavour, according to their best judgment, to adjust that rate, not to the temporary and occasional, but to the average and ordinary price of the produce.