six o'clock
The guide 's gourd , not quite half full , was all that was left for us three ! Having finished their repast , my two companions laid themselves down upon their rugs , and found in sleep a remedy for their fatigue and sufferings . As for me , I could not sleep , I lay counting the hours until morning . The next morning , Saturday , at six o'clock , we started again . Twenty minutes later we suddenly came upon a vast excavation . From its mighty extent I saw at once that the hand of man could have had nothing to do with this coal mine ; the vault above would have fallen in ; as it was , it was only held together by some miracle of nature . This mighty natural cavern was about a hundred feet wide , by about a hundred and fifty high .