Making sure of the direction in which the strong odor of sulphur was wafted to him, Fenn temporarily abandoned his quest for the place of the turtles. The odor grew more pronounced, for some sulphur springs are so strongly impregnated with that chemical in solution that the smell carries for miles, especially on a windy day. The region where the chums had gone camping, as they learned later, was well supplied with these freaks of nature.