 What did Don use as a method for seeing over the edge of the stream?
A National Guard officer volunteered to take a jeep down into the pit, having found a spot that seemed navigable. The object loomed out of a cloudbank at twelve thousand feet and Studley changed course to avoid it. Don made his way up to the locomotive and found a bigger knot of people gathered in front of the cowcatcher. Don Cort and the fireman walked cautiously toward the edge while the professor ambled ahead with the familiarity of one who had been there before. Nevertheless, Don could see that it apparently was a neat, sharp edge, not one of your old ragged, random edges such as might have been caused by an explosion.
 A compact from Alis.
 A mirror found in the Cavalier dorms.  A compact from Miss Jervis.  A compact from Alis.  A camera to take a photograph.