“Exactly. So, in order to get an idea of the way the bones must have been during life, we dissected and studied nearly every living reptile, especially the alligators and the lizards, and worked out the muscles of almost all of them. Then the corresponding bones in the Brontosaurus were compared, and the position and size of the muscles worked out, as far as they could be judged from the notches and grooves still preserved on the bones.” “My word, that’s real work!” “You can be sure it was real work,” the professor assured him. “Then, Perry, we articulated the skeleton loosely, and the position and size of each muscle were judged from strips of paper we pasted on the bones to represent the muscles. As we moved the joints, we watched the paper move, and compared the movement of the paper with the muscles of the living reptiles. When we got the limbs into the proper places, the whole question of the weight and pose of the body, as it must have been in life, was worked out, and finally the skeleton was mounted in what must have been the characteristic position that the Brontosaurus assumed during life. That took us another three years. It was not until three years later, or six years altogether, that the Brontosaurus skeleton was finally mounted.” [Illustration: _Courtesy of American Museum of Natural History._ BRONTOSAURUS IN HIS NATIVE SWAMP. Huge reptile of ten million years ago, weighing not less than 38 tons, seventy feet long, once a widely spread American species.] “Meantime, Uncle George, I suppose you had found the Bone Cabin quarry,” said the boy, anxious to bring his uncle back to the story of the discovery. “We first found that quarry in the autumn of the year we began work on the Como Bluffs,” the professor replied. “One of our fellows was doing a little prospecting over the plains, as we felt we had exhausted the Como Bluffs specimens that had been exposed so far. Now, if you remember, Perry, as we rode out here this afternoon, we sighted the Laramie Mountains and the Freeze Out Hills and I pointed out to you that they were quite recent in origin. As those ranges were uplifted, they crushed together the surface of the level plains and crumpled them into rock waves. Erosion cut away the tops of those waves and exposed the rock at the edges, though, of course, the lower parts of these rock waves are still underground and it will take the erosion of many centuries to expose them. The bone-hunters of the future will find more treasures waiting for them on the Laramie Plains, just as we have done.