In order, however, that this equality may take place in the whole of their advantages or disadvantages, three things are requisite, even where there is the most perfect freedom. First the employments must be well known and long established in the neighbourhood; secondly, they must be in their ordinary, or what may be called their natural state; and, thirdly, they must be the sole or principal employments of those who occupy them. First, this equality can take place only in those employments which are well known, and have been long established in the neighbourhood. Where all other circumstances are equal, wages are generally higher in new than in old trades. When a projector attempts to establish a new manufacture, he must at first entice his workmen from other employments, by higher wages than they can either earn in their own trades, or than the nature of his work would otherwise require; and a considerable time must pass away before he can venture to reduce them to the common level. Manufactures for which the demand arises altogether from fashion and fancy, are continually changing, and seldom last long enough to be considered as old established manufactures. Those, on the contrary, for which the demand arises chiefly from use or necessity, are less liable to change, and the same form or fabric may continue in demand for whole centuries together. The wages of labour, therefore, are likely to be higher in manufactures of the former, than in those of the latter kind. Birmingham deals chiefly in manufactures of the former kind; Sheffield in those of the latter; and the wages of labour in those two different places are said to be suitable to this difference in the nature of their manufactures. The establishment of any new manufacture, of any new branch of commerce, or of any new practice in agriculture, is always a speculation from which the projector promises himself extraordinary profits. These profits sometimes are very great, and sometimes, more frequently, perhaps, they are quite otherwise; but, in general, they bear no regular proportion to those of other old trades in the neighbourhood. If the project succeeds, they are commonly at first very high. When the trade or practice becomes thoroughly established and well known, the competition reduces them to the level of other trades. Secondly, this equality in the whole of the advantages and disadvantages of the different employments of labour and stock, can take place only in the ordinary, or what may be called the natural state of those employments.