four o'clock
He might have shortened the journey had he but known how to work out his course by the compass . Tad realized this . He told himself that he could not afford to try any experiment , however . His judgment was verified , when , shortly after four o'clock he was gratified by sighting several pillars of black smoke . `` That 's the place . I 've hit it ! '' exulted the lad , breaking into a sharp trot , which he increased until he was running at top speed .