This is a science-fiction story. History is a science; the other part is, as all Americans know, the most fictional field we have today. He settled himself comfortably in his seat, and carefully put the helmet on, pulling it down firmly until it was properly seated. For a moment, he could see nothing. Then his hand moved up and, with a flick of the wrist, lifted the visor. Ahead of him, in serried array, with lances erect and pennons flying, was the forward part of the column. Far ahead, he knew