OCR Text |
Show 230 PRESSURE OF WATER. strata of firm stone many miles in e~tent, an~ many fathoms in thickness, bent and tw1sted as ~f they were pancakes, or turned on their edges ~s 1f they were ice-brash of but one hour's formatiOn bef?re the roll of the ocean, or the wing of the ~n~rnmg gale · or when we find granite moulded as 1f 1t had been' dough. As little need we wonder when _we find a "dike" of diffLTent or more modern f<?rmatwn, or a "lode" of spar and metallic or~, cleavmg sheer thrmwh a mountain ridge, or extendmg many degrees on th~ girdle of the earth. To a power that could overcome such resistance we can set no bo':lnd~. But vast as that re.sistance is when we. brmg It to the test of numbers-the onl~ o!le by whtch ~e can get an accurate jucgment-1t 1s really nothmg as compared with the resistance farther down ; for go but one-fourth of the distance to the earth's centre, and the pressure on a single inch wo?ld make the greatest mountain, nay, all the land ~h1ch stands out above the mean level of the sea, ktck the beam. Now, as we have state~ the mean depth of the water at rather less than It would come to, ~ccordinrr to the guesses of the most eminent and ennnently ca~tious men, who have calculated as far as th_ey could and then speculated on that most extensive suhje~t, it must follow that whenever some parts were elevated so as to be at a less depth, other parts must have been depressed so as to be 3:t a gre~ter. Thus the very pressure of the wa_ter, which r~s1sted the powers by which the contments and _Islan~s were elevated "vould <Jssist those powers m theu prorrress, after' the elevation was begun. Whatev~r of ; atter was forced upward by the h?at (for 1f heat was not the instrument, we know 1t not, and heat is fully adequate to the task),_ there would be no vacar.cy left, because the supe~n~cumbent pr~ssure would ser.d down the .rema~mng parts With more energy and effect than 1t resisted ~he ascen~ing ; so that, as the mountain reared Its head, It DESIRE FOR KNOWLEDGE. 231 w(:m~d continue. to do so with less and less of the O~Igmal propellmg force; and when it came to the atr an~l the sunbeams, its labour would, comparatively speakmg, be ~t an end-at least, compared with the first struggle Ill the deep. To those who have been accustomed to look at nature only on the small scale, and as conducive to th~ puny possessions of man's little life, those specu- - latwns may appear to have but little to do with the "popular" observation of nature; but, in truth, they belong to the popular, and not to the systematic part of natural h~story: for they come upon the popular student m his very novitiate, nay, they proba~ly force themselves more or less upon the attentwn of all young people, learned and unlearned, when t~ey are pe_rmitted to think for themselves. There 1s not a child. but will bre.ak its toys almost at th~ momet~t that 1t gets them mto its hands-and certamly th~ m~tant that it has seen their external novelty, whiCh IS soon seen; and it takes a great de~l~ both of precept and example, and sometimes chi~mg and chastisement, to break the child of that hab1~-s? per~ectly painful and unnatural to it is poss~ sswn m which there is no enjoyment. To defend etther the natural propensity of the child or the lesson of early care which is inculcated by means of the rattle and the penny trumpet, is not our busines~. It may be that when the toy is saved the desire of knowledge in the child is broken· a~d it !~lay be that frugality is produced by the less~n. If Jt be the f?rf!ler, "the whistle" is, indeed, a costly one ; and If 1t be the latter, probably the best way would be not to purchase the toy at all. But all tha~ we con.te?d for is the fact, and that must b.e ad.mi.tted, as It IS one to which there is no exce~twn, If. It has not been produced by teaching. Now If a desu~ t~ k~ow the structure of every thing that comes withm. Its observation be irresistibly natural to every child, until that child is flattered or |