Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

682 UEMAIIKS ON THE DELUGE. the ocean descends, and made chiefly in temperate or cold climates. Having no pretension to more knowledge than any obser- vant seaman may acquire in the course of a few years active employment afloat, it would be as vain as presumptuous in me, were I to offer any conjecture about the central mass of the earth. Perhaps, at a future day, when the nature of aerolites ; the agency of electricity ; and of electric communica- tion through the superficial, if not through the interior regions of the globe, are better known, other opinions, respect- ing this wonderful world which we inhabit, may be formed by philosophers. I have now fulfilled my intention of endeavouring to be useful, in however small a degree, to young persons of my own profession. If the few remarks laid before them, in this and the preceding chapter, at all increase their interest in the subjects spoken of; and tend, even in the least, to warn them against assenting hastily to new theories — while they induce a closer examination into the Record of truth — my object in writing them will be fully attained.