 a 50-foot pendulum from the top floor to the basement. And on the bob, we had a little motor that misfired. And so we sent a tremendous cloud of this corrosive nitrous and tetroxide all through the building. We were thrown out of the building the next day, of course. Then we built what we call the gas apparatus on the outside of Guggenheim. There was a platform on the east end of Guggenheim at that time. I don't know what's there now. I guess there's another building.