Plumbing at Fallingwaters

So a couple friends and I recently took the tour of the Frank Loyd Wright house Fallingwaters. Our tour group had several foreigners in it that were lets say disruptive to the experience. The tour guide felt bad (she was fantastic and did nothing wrong) so she asked if we would like to see the kitchen and basement areas which are normally not on the tour. Well how could we say no to that. Anyway in the basement I saw something I had never seen nor heard of before....threaded copper pipe. Yes the plumbing in that house is threaded copper with what appeared to be brass fittings. I am sure plenty of you have seen or heard of this, but I found it quite interesting so I thought I would share. Oh and before you ask no I didn't see the boiler, I asked and she said no to seeing the boiler room. I tried!