I can't figure out where the batteries go.

It might be useful!

My dad had lots of odds and ends in his shop. For example, this block with a rotating dowel attached to it; I have no idea what it does, but…
Old Headache Powder envelope

MY BRAIN HURTS

I guess when your head hurts so bad that you can't even stand the sight of a trademark stamp, you don't care about side effects, but acetanilid will do a…