Practical vs. theoretical knowledge

Interesting, especially to the Family Classicist:

Harvard classics researcher Mark Schiefsky has shown that many great technical innovations of antiquity, such as the balance and steelyard, were created by craftspeople with no theoretical training in mathematics. A steelyard is a balance with unequal arms, whose operation is based on ancient mathematician Archimedes’ law of the lever. Schiefsky poo-poos the idea that you need a fancy law to make a steelyard, and in fact has proven that steelyards were in use long before Archimedes explained it.

Schiefsky discovered evidence from early Greek writings that craftspeople in the 5th century B.C. used steelyards in the agora, or marketplace :

People assume that Archimedes was the first to use the steelyard because they suppose you can’t create one without knowing the law of the lever. In fact, you can–and people did. Craftsmen had their own set of rules for making the scale and calibrating the device. If someone brings a 100-pound slab of meat to the agora, how do you weigh it? It would be nice to have a 10-pound counterweight instead of a 100-pound counterweight, but to do so you need to change the balance point and ostensibly understand the principle of proportionality between weight and distance from the fulcrum. Yet, these craftsmen were able to use and calibrate these devices without understanding the law of the lever.