Have you ever sat around a campfire toasting marshmallows and telling stories? Fun, right? But would it be as much fun if that campfire was the only way you had to keep warm, cook your food, and light the darkness?
That’s how it was for cave dwellers thousands of years ago. Fire, fed by wood, was one of the earliest forms of energy humans used. But people are a clever bunch. And as the centuries rolled by, they discovered more and more ways of getting their work done. Let’s take a look at some of them.
