 You will understand how easy it is for an especially violent gust to snatch one of the umbrellas up and send it cartwheeling along the beach like a tomahawk or an accessory in a knife-throwing act or something thrown by a gladiator across the dusty floor of the Coliseum. You will understand also that there is something about the low-slung design of an old-fashioned deck chair that makes it difficult for someone like Sybil Hadley in her late 60s to get out of that chair in a hurry.