Bad Intentions Don’t Make Money and Honesty Doesn’t Lose Money

Chinese scales.

The old shopkeeper of Fengyu saw that warfare made business complex, so he devised an idea to make more money. One day, he invited a scale maker to his home. Thinking they were alone, he told the scale maker, "Please make a scale for me that weighs 15-and-a-half taels to a catty. I will give you ten extra coins for doing so." (Image: via Wikipedia)