By a division of labor we mean the transferring of work which has formerly been done by one person to several persons in such a way that each of these performs only a separate part of the previous total labor. There are several different kinds of division of labor which may be illustrated as follows. In the first place, where formerly one man farmed and made shoes and built houses and worked in iron, later four men performed these tasks for the community. This kind of division of labor we shall call the formation of trades.

In the second place, to take a classic example, where one man formerly made pins, in the time of Adam Smith this work was divided up among several men. "One man draws out the wire; another straights it; a third cuts it; a fourth points it; a fifth grinds it at the top for receiving the head; to make the head requires two or three distinct operations," etc. This we shall call the subdivision of labor.

A third kind of division of labor is represented by the division of production. Originally the farmer raised the wheat, ground it into flour, and made it into bread. Now the one product, the bread, is not only worked upon but also owned by three different classes of workers in the various stages of its production. The farmer sells the wheat to the miller, who grinds it and sells the flour to the baker, who makes bread of it. This differs from the pin illustration in that during the manufacture of the pin there was no change in ownership.

A fourth kind of division of labor which we shall call division of trades is illustrated where in a trade there are several distinct articles made, and where each of these articles comes to be made by special workers who thus develop separate trades. Thus the blacksmiths in olden times made shoes and nails and nailed the shoes to the horses' feet, besides doing other things which the blacksmith no longer does. To-day there is the special trade of horseshoeing. The horseshoer fastens the shoe to the foot, but the shoe and the nails are made by two other distinct trades.

As a fifth kind of division of labor we may instance the displacement of labor by machinery. Former direct processes have become roundabout processes with the result that what was formerly a single task is now divided up into several distinct tasks. For example, with the advent of the sewing machine a part of the work of the seamstress which was formerly done by hand is now done by the seamstress working with hand and foot, while a new group of producers, namely, the makers of sewing machines, now work at tasks which have taken the place of much of the former work of the seamstress.

71. "Practice makes perfect." - The narrower the range of operations performed by the individual worker, the greater is the dexterity acquired in their performance. Practice makes perfect. Where a few simple operations are performed over and over again, day in and day out, year in and year out, they become almost automatic. The hand and the eye become so accustomed to them that they are performed without conscious effort. Moreover, the oftener the single operation is performed the greater is the tendency to eliminate false motions and to perform the operation in the simplest way. This increased quickness of hand and the saving of motions that accompany specialization result in making divided labor much more productive than undivided labor.