National Geographic : 1953 Mar
399 Steel Teeth Grip the Glazed Floor; No Step IsSafe Without Them Exploration would have been impossible had the little party failed towear crampons, sharp spikes strapped to boots. If cinched too tight, the straps slowed circulation, inviting frozen feet. Above: Explorers crawl through a "cat hole," a low passage inthe rock. Below: Only Maud's steel-shod boots are visible as she wriggles on her stomach ontothe ledge opening above Frozen Niagara (page 395).