Now, the measure of the moon’s distance involves no principle more abstruse than the measure of the distance of a tree on the opposite bank of a river; and the Professor shows that the methods used for measuring astronomical distances are, in some applications, absolutely the same as the methods of ordinary theodolite surveying, and are in other applications equivalent to them; and that, in fact, there is nothing in their principles which will present the smallest difficulty to a person who has attempted the common practice of plotting from angular measures.[125] The habit of beholding the spectacle of the sun gradually sinking, to disappear after a time below the level of the sea,—this habit, we say, and our astronomical knowledge, have long since familiarised us with the phenomenon which, undoubtedly, would appear inexplicable were we to witness it for the first time, and without being prepared. Who has not in childhood felt this wonder? The ancients were far from being able to account for it: some Greek philosophers regarded the sun as an inflamed mass, which plunged itself every night into the waters of the sea; and they pretended to have heard a hissing noise! We have found the same idea lingering among the credulous peasantry of Sussex. We remember our first nurse, a native of Battle, used to relate that, from the cliffs at Eastbourne, she had seen the comet of 1769 dip its tail into the sea, and that she had distinctly heard the “hissing noise.” Such is the persistence of certain impressions, which, monstrous as they are, can only be explained away by reasoning.[126] --------------------- Footnote 125: See Prof. Airy’s _Six Lectures on Astronomy_. Footnote 126: See _Things not Generally Known_, First Series, p. 11. ---------------------------- PHYSIOGNOMY. Sir David Brewster, in his introductory Address to the University of Edinburgh, 1862-3, remarked that one of the characteristics of the age in which we live was its love of the mysterious and marvellous.