16-year-old Helena Muffly wrote exactly 100 years ago today:
Saturday, November 25, 1911: Just exactly one month yet. I must begin to be good and oh so nice. I was terrible busy this forenoon. This afternoon I studied a bit and popped some popcorn. My first attempt resulted in half or about a third of the contents jumping out of the pan, but the next time I was more successful.
Her middle-aged granddaughter’s comments 100 years later:
Hmm, I wonder how the popping corn managed to jump out of the pan. People used to pop corn in a heavy frying pan, but they generally put a cover on the pan.
To make popcorn heat vegetable oil in a heavy frying pan until it is hot. Use a medium heat or flame.
Put some popcorn in the pan. (Use about 1/3 cup for an average sized pan.) Cover pan.
Hold about ½ inch above the burner and shake the pan. You don’t need to shake it rapidly; it’s okay to shake the pan relatively slowly.
Shake until the corn stops popping, and then remove from the heat and open lid.
A Hundred Years Ago 
This is the way we popped popcorn in the 60s and early 70s, until my mother purchased an electric popper.
When I was a child my family had a popcorn pan that had a crank attached to the lid that we turned to stir the popcorn, but I can remember visiting friends’ homes where they made popcorn in a frying pan. When I made popcorn in a frying pan to illustrate this post, I was pleasantly surprised how well it turned out.