half past eight
`` They are going to burn three small camp fires set in a triangle , you remember , '' remarked Bob . `` Therefore , '' suggested . Ned , `` all keep a sharp lookout . '' At half past eight Ned showed some concern . No lights had been sighted and the reckoning showed that they must be within two or three miles of the probable location of the camp . Another fifteen minutes went by , and yet no signal fires were seen . They had now passed over the junction of the two rivers , if their calculations were right , and Ned and Alan were in a quandary .