two o'clock
When the boys awoke on the eventful day , naturally their first thoughts were of the machine in which they hoped so ardently to win the aviation trophy . Their dismay may be better imagined than put into words when they discovered their loss . `` It puts us out of the race , '' was Harry 's despairing cry . `` We can never replace it by two o'clock , the time set for the start , '' was Frank 's despairing exclamation . Suddenly they realized that Sanborn also was missing . Like a flash Frank realized that it must have been their mechanic who had done the damage . It would have been impossible for any one to enter the shed from the outside without leaving traces , as the lock was on the interior of the door .