“So that’s what he looked like!” exclaimed the old merchant. “I can give you a better idea yet. Hold on a bit,” said Perry, and he hurried away again. Back he came, carrying in one hand the companion wing, and in his other hand a wax model of the head and towering crest of the great flying reptile. As soon as this latter was placed beside the scattered array of bones on the table that represented the skull, their relation to each other was shown at once. Perry then laid the other wing on the table, the two great brown membrane-like wings stretching their whole spread of twenty-one feet, and making it seem as though that giant of the air had just glided down upon that workshop table. “Great guns,” said the financier, “what a monster!” “Doesn’t that give you an idea of his size, though!” exclaimed the boy. His father looked thoughtfully at the bones of the skeleton lying embedded in the pieces of Kansas chalk in which they had been found, and at the model with its semi-transparent wings that lay upon it, and said thoughtfully: “It’s too bad we couldn’t make an entire hall, Perry, containing huge life-size models of all the kinds of trees that lived at that time, with perhaps a cliff and sea-shore and a few of those Pteranodons—models of course—flying around. I believe in that way people would get the idea of archaic life much more easily than they would from specimens in a glass case.” “Oh, Father!” cried the lad excitedly, and stopped. “Well?” “It would be bully,” the boy agreed, “but you’d need such miles of space! The tree ferns would have to be a hundred feet high, and the cliff two hundred feet, so as to get the perspective right; the hall would have to be a couple of hundred feet square, and we’d need a different hall for each of the important periods.” “About how many?” “Seven or eight, I should think.” The old merchant shook his head. “I’m pretty well fixed,” he said, “but I couldn’t stand for anything like that. Those halls would cost half a million apiece.” [Illustration: _Courtesy of American Museum of Natural History._ INTO THE HEART OF MEXICO. Museum expedition leader in the Tree Cactus Country.] [Illustration: CARRYING SHELL OF GLYPTODONT Eight Mexican peons bearing armor of giant armadillo.] “If you wanted to, Father—” the boy began, and stopped. “Well?” “You can get pretty nearly that effect by making models on a small scale, say, an inch to the foot. Then the tree ferns would be ten feet high, the Pteranodons would be two feet and all the other animals would be to scale. If you worked in the perspective and did the lighting the way that it’s done on the stage, people could get almost the same effect as by a big hall.” The merchant looked thoughtfully at his son. “That’s a good idea of yours, Perry,” he said. “It’s not my idea,” the lad rejoined, “there’s a chap who’s worked it out for the Children’s Museum in Brooklyn and the Metropolitan Museum in New York. His stuff is great!”