The rates of wages in different employments are governed by #the laws of supply and demand# which we shall afterwards consider. Just as goods rise in price when there is little in the market and much is wanted, so the price of men's labour rises when much of any particular kind is wanted and little is to be had. It does not matter much whether we speak of demand for goods or demand for the labour, which is necessary to make the goods. If more things of a certain sort are wanted, then more men able to make them must be found. If I buy an aneroid barometer, I use up the labour of a man able to make such a barometer; if many people take a fancy to have aneroid barometers, and only a few workmen have the necessary skill to make them, they can ask a high price for their labour. It is true that people buying barometers do not usually pay the workmen for making them; a man with capital gets the barometers made beforehand and puts them in shops ready for sale. The capitalist advances the wages of the workmen, but this is only for a few weeks or months, and according as the demand for barometers is brisk or slow, he employs more or fewer workmen. Thus, #demand for commodities comes to nearly, though not quite, the same thing as demand for labour#. There is the profit of the capitalist to be considered as well; but, with this exception, #rates of wages are governed by the same laws of supply and demand as the prices of goods#. Anything, then, which affects the numbers of men able and willing to do a particular kind of work, affects the wages of such men. Thus the principal circumstance governing wages is the comparative numbers of persons brought up with various degrees of strength, both of body and mind. The greater number of ordinary men, while in good health, have sufficient strength of arms and legs to do common work; the supply of such men is consequently very large, and, unless they can acquire some peculiar knowledge or skill, they cannot expect high wages. Dwarfs and giants are always much less common than men of average size; if there happened to be any work of importance which could only be done by dwarfs or giants, they could demand high wages. Dwarfs, however, are of no special use except to exhibit as curiosities; very large strong men, too, are not generally speaking of any particular use, because most heavy work is now done by machinery. They can, however, still get very high wages in hewing coal, or puddling iron, because this is work, requiring great strength and endurance, which is not yet commonly done by machinery. Iron puddlers sometimes earn as much as L250 a year.