“Sure. So if the collector who found those bones cleared away a space a little larger than the spread of the Pteranodon, say a stretch thirty feet square, and worked that down to a level, he’d really be looking at the bottom of the ocean as it was when the Pteranodon sank down. If he explored that stretch for a few inches further down, he’d certainly find all the bones he would be likely to find, for even an inch of chalk would mean a thousand-years’ deposit.” “That may be all right, son,” said his father, “and you’ve made a good case for the collector. But just the same, the bones must be somewhere.” “Sure, but where? See, right here, Father,” and the lad put his finger on the skeleton, “there’s the place where the sternum ought to be, one of the biggest bones of the whole Pteranodon. It wasn’t found at all. Yet you’d think that the biggest bone would be the easiest to find.” “That’s just what I’m saying. It must be somewhere. A bone from a dead bird can’t get up and walk off by itself.” “No, but a big primitive fish or a crab, or something, could have pulled away the bone when making his dinner on the dead Pteranodon at the bottom of the sea. Anyway, it’s a rare thing when there aren’t some bones missing in a fossil. In the Fayum, it used to seem to me an awful shame that the skeletons were so often broken up into little bits. But we had to take them as they came.” “You’ll make up the rest of the skeleton in plaster, I suppose?” “That’s nearly done, Father,” the boy replied. “But we’re not going to take the skeleton free from the chalk and mount it.” “Why not?” “Couldn’t be done successfully. As I was telling you, the bones are crushed. See, Father, a Pteranodon’s bones are hollow, like a thin pasteboard tube, and the pressure of the overlying chalk has squashed them flat, and splintered them. It would be an awful job to rebuild that tubular bone. No, we’re going to chisel away the chalk for about an inch below the level of the bones, soaking them meanwhile in shellac until they won’t absorb any more and cementing together the pieces that are cracked and broken. Then we’ll make a plaster model of the whole base, fitting in the bits of chalk we have, and we’ll color that pink like the rock in which the bones were found. On that model, which will be exactly to scale, we’ll be able to see exactly where the missing bones come and we’ll mold them on the model. We’ll color them slightly different from the true bones, so that an expert can see right away which are the restored parts, but the public will get the idea of the beast as a whole.” “And your restoration will be of wax?” “We’ve got a regular composition for that, and I’m molding it over a steel frame so as to give it strength. Then I’ll paint it up to look as much like life as possible.” “How do you know what color to paint it?” queried his father. “There wasn’t any artist in existence to take notes when Pteranodon was flying around.”