A friend of mine sent me a link to this site: A Scientist’s Curiosity Cabinet. Professor T. Ross Kelly teaches chemistry at Boston College, and has been collecting little oddities for over two decades. Many of them illustrate various scientific principles; he has motors, cannons, flash paper, illusions, and more.
With the help of two Boston College undergraduates, Omar Khan and Jacy Lundberg, Kelly is now building a new collection: of videos demonstrating and explaining how the various gizmos in his curiosity cabinet work. My kids and I were just learning about electric motors recently, so it was fun to see a collection of other types of motors here.