To me is one of the most fascinating inventors I ever studied. I heard about him through a doctor friend of mine in the mid-70's who was following his research and working with Tesla coils back then (ah, but I digress). HE ended up with the CIA and FBI down his back and was eventually burned out of his house and lab on purpose (ah, but I digress again). This man built the Teslar watch and held 57 patents.

Go on Alibris and find an old copy of "Tesla... Man Out of Time" by Margaret Cheney. See if you can find the old paperback with the photos. He had an EXTRAORDINARY life! And he believed his real parents came from the stars. He also had an uncanny ability to SEE his inventions clearly operating in his mind in 3-D BEFORE he constructed them.

He had a love affair with pigeons and some very unusual stories to tell.I actually have an old worn out copy of his 32 page auto-biography told in his own words. He was an enigma, like Edward Leedskalnin who built the Coral Castle.

I think it's fascinating that your son is trying to find out the principles Tesla used. Sounds like you have a full household.