about six o'clock
`` It is farther away than you seem to think , _ fräulein _ ; but the real difficulty is the ice . Unless you cross some of the crevasses in the early morning , before the sun has had time to undo the work accomplished by the night 's frost , you run a great risk . And that is why you must be ready to start from the _ cabane _ at dawn . Moreover , at this time of year , you get the finest view about six o'clock . '' The mention of crevasses was somewhat awesome . `` Is it necessary to be roped when one tries that climb ? '' she asked .