About noon
nothing can long remain a mystery to that august brain . '' Night drew on apace , the sentinel crickets were posted , the Glow-Worm and Fire-Fly lamps were lighted , and the camp sank to silence and sleep . After breakfast in the morning , the expedition moved on . About noon a great avenue was reached , which had in it two endless parallel bars of some kind of hard black substance , raised the height of the tallest Bull Frog , above the general level . The scientists climbed up on these and examined and tested them in various ways . They walked along them for a great distance , but found no end and no break in them . They could arrive at no decision .