The selections on these pages are some of the less dangerous projects from an ancient two-volume book set called, The Boy Mechanic. Unlike the more recent, "Dangerous Book for Boys," some of the projects in these books are really dangerous... at least if you consider molten metal and explosives and such to be dangerous. However, though they are very dated, some of the projects still look interesting and helpful.
I've included several that stood out to me. I've tried some and they work; one that doesn't; and some I don't know at all. Anyway, you are completely on your own.