I used to live near Doylestown and have visited all of the Mercer exhibits there. Each is a marvel in its own right.
The Mercer Museum is essentially a collection of pre-industrial age tooling and gadgetry assembled and displayed by Mr. Mercer as a knowledge vault. He figured that at some point easy, cheap power would fail us and his collection would lead us out of darkness.
He’s got everything from tortoise shell combs to whaling boats on display.
If you ever find yourself in or near Bucks County, PA it is surely worth your time to pay a visit. His home and tile works are, as I mentioned, also very interesting and quite close by.