the hour of twelve midnight
This was the fact that the tide rose and fell with constant regularity , instead of being affected by the changes of the moon as in our own country , and as it is in most other parts of the world -- at least in all those parts with which I am acquainted . Every day and every night , at twelve o'clock precisely , the tide is at the full ; and at six o'clock every morning and evening it is ebb . I can speak with much confidence on this singular circumstance , as we took particular note of it , and never found it to alter . Of course , I must admit , we had to guess the hour of twelve midnight , and I think we could do this pretty correctly ; but in regard to twelve noon we are quite positive , because we easily found the highest point that the sun reached in the sky by placing ourselves at a certain spot whence we observed the sharp summit of a cliff resting against the sky , just where the sun passed . Jack and I were surprised that we had not noticed this the first few days of our residence here , and could only account for it by our being so much taken up with the more obvious wonders of our novel situation . I have since learned , however , that this want of observation is a sad and very common infirmity of human nature , there being hundreds of persons before whose eyes the most wonderful things are passing every day , who nevertheless are totally ignorant of them . I therefore have to record my sympathy with such persons , and to recommend to them a course of conduct which I have now for a long time myself adopted -- namely , the habit of forcing my attention upon _ all _ things that go on around me , and of taking some degree of interest in them , whether I feel it naturally or not .