It did at least have an organ—or so the visitors thought at first. The largest single object in the room was a box, the size of a Vagabond-shack but much more finely wrought, of oak planks cleverly joined together, and caulked at the corners with tar and oakum. To one side of it was a row of four large bellows, with a wooden rail mounted a few feet above them. Two women were gripping the rail. Each of them divided her weight between a pair of bellows, one under each foot; these had been rigged in such a way that as one foot descended, expelling air into the great wind-chest, the other inhaled and rose up. The women seemed to be scaling an endless stair. They were a matched set of great busty hippy frazzle-haired wenches with apple-red cheeks, getting riper and shinier by the moment, and they seemed to find this great fun. While gazing with open curiosity at the visitors, they kept an eye on a glass U-tube filled with mercury, which started one way whenever one of them took her weight off of a foot, and jerked back as she shifted it to the other. A level had been marked on one side of the tube by tying a red ribbon around it. None of the visitors needed to have it explained that the goal of the exercise was to make the mercury climb until it reached the height of that ribbon.