division of labour, by reducing every man’s business to some one simple operation, and by making this operation the sole employment of his life, necessarily increased very much dexterity of the workman. A common smith, who, though accustomed to handle the hammer, has never been used to make nails, if upon some particular occasion he is obliged to attempt it, will scarce, I am assured, be able to make above two or three hundred nails in a day, and those too very bad ones. A smith who has been accustomed to make nails, but whose sole or principal business has not been that of a nailer, can seldom with his utmost diligence make more than eight hundred or a thousand nails in a day.

I have seen several boys under twenty years of age who had never exercised any other trade but that of making nails, and who, when they