There is something irresistibly funny in the spectacle of a group of “experts” contemplating a new discovery – say, the bones of a Neanderthal man – and solemnly pronouncing it worthless and unconvincing piece of trash… and then, twenty years later, when many similar discoveries have been made elsewhere, solemnly retracting their first opinion. The earliest collectors of fossils, the first explorers of the homes of cave men, were nearly always called cranks, and their finds were rejected with derision. And then (sometimes, though not always) in their own lifetime, the evidence grew and grew, until no one but a genuine crank could resist its overpowering conviction. It is really surprising to learn how many facts have been revealed to help us in reconstructing the world of the distant past. Hairy mammoths have been discovered – not a few, but thousands, some with the undigested food still in their stomachs. We have not merely one single cave painted by the artists of the Stone Age, but scores and scores. We have thousands of the tools of Stone Age men, dozens of their skeletons (some of them elaborately interred), heaps of their intimate rubbish, even their footprints and their hand-prints. It was simply because the cave men could not read and write, and because the slow lapse of time filled up or concealed their dwellings, that we did not learn about them until relatively recently. But we can read many, many wordless records of the past.