Chapter

1 XII  |      He was about to make an observation to the guide, who without
2 XIV  |   and if you add to this the observation that the wind and rain are
3 XVIII| Direction, E.S.E.”~This last observation applied to the dark gallery,
4 XVIII|      indeed.”~“Well?”~“By my observation we are at 10,000 feet below
5 XXXII|      I was to register every observation, make entries of interesting
6 XXXVI|    approximation.”~“The last observation,” I remarked, “was made
7 XLII |    of our situation from the observation of the strata. This calculation