Alone, an untrained worker could scarcely make one pin a day, Adam Smith wrote.

Making a pin takes about eighteen distinct operations.

One man draws the wire, another straightens it, a third cuts it, a fourth points it.

In one small workshop, ten men split the operations between them.

They made about 12 pounds of pins a day, over 4,000 pins to the pound.

12 × 4,000 = 48,000 pins a day.

That is 4,800 pins for each man.

Alone, none could make twenty: 4,800 is 240 times twenty.

Smith's three reasons: skill, no time lost switching, and machines.

We expect our dinner from the baker's own interest, not his kindness.

Seeking his own gain, a trader is led by an invisible hand.