"beginning with its external features (and full of novelty and interest, even, as regards those), led to the further inquiry as to what it was made of, and then to finding unexpected relations which it bore to the Earth and our own daily lives on it, the conclusion being that, in the physical sense, it made us and re-creates us, a it were, daily, and the knowledge of the intimate ties which unite man with it brings results of the most practical and important kind, which a generation ago were unguessed at."