127 



SCIENTIFIC SIDE-LIGHTS 



Constituent* 

 Contraction 



what size and of what material are the heav- 

 ens; whether they be at rest or in motion; 

 what is the magnitude of the earth; on 

 what foundations is it suspended or bal- 

 anced to dispute and conjecture upon such 

 matters is just as ii we chose to discuss 

 what we think of a city in a remote country, 

 of which we never heard but the name." 

 TYNDALL Lectures on Light, lect. 1, p. 13. 

 (A., 1898.) 



627. CONTINENTS AND OCEANS 



PERSISTENT The Same General Forma- 

 tions from Geologic Times. We now know 

 for certain that the sands and clays washed 

 off the land whether by the action of ice or 

 river- waters on its surface, or by the wear- 

 ing away of its margin by the waves of the 

 sea sink to the sea-bottom long before they 

 reach the deeper abysses; not the least trace 

 of such sediments having been anywhere 

 found at a distance from the continental 

 platforms. And thus the study of the de- 

 posits on the oceanic sea-bed has fully con- 

 firmed the conclusion drawn from the pres- 

 ent t configuration of the earth's surface, as 

 to the general persistence of those original 

 inequalities which have served as the bases 

 of the existing continents, and the floors of 

 the great ocean-basins. 



In the masterly lecture on " Geographical 

 Evolution," . . . given by Professor 

 Geikie before the Royal Geographical So- 

 ciety, ... he thus sums up: 



" From all this evidence we may legiti- 

 mately conclude that the present land of the 

 globe, tho composed in great measure of ma- 

 rine formations, has never lain under the 

 deep sea, but that its site must always have 

 been near land. Even its thick marine lime- 

 stones are the deposits of comparatively 

 shallow water. Whether or not any trace of 

 aboriginal land may now be discoverable, the 

 characters of the most unequivocally marine 

 formations bear emphatic testimony to the 

 proximity of a terrestrial surface. The pres- 

 ent continental ridges have probably always 

 existed in some form ; and as a corollary we 

 may infer that the present deep ocean-basins 

 likewise date from the remotest geological 

 antiquity." CARPENTER Nature and Man, 

 lect. 11, p. 332. (A., 1889.) 



628. CONTINENTS PERPETUALLY 

 WASHED INTO THE SEA The disinte- 

 grated materials, produced by chemical and 

 mechanical actions of the atmospheric wa- 

 ters upon rock-masses, are by floods, rivers, 

 and glaciers gradually transported from 

 higher to lower levels; and sooner or later 

 every fragment, when it has once been sepa- 

 rated from a mountain-top, must reach the 

 ocean, where these materials are accumu- 

 lated and arranged to form new rocks. 

 JUDD Volcanoes, ch. 10, p. 284. (A., 1899.) 



629. CONTINENTS, RELATIVE 

 HEIGHT OF The "Sea-level" a Fluctuating 

 Line. The existing land-surfaces of the 

 globe are composed most frequently of ma- 



rine strata. There are apparently only twa 

 ways in which this phenomenon can be ac- 

 counted for, and these explanations come to- 

 much the same thing. Either the general 

 level of the ocean has fallen, or wide areas 

 of the sea-floor have been pushed up from 

 below and converted into dry land. Both 

 changes appear to have taken place. The 

 bed of the sea has sunk from time to time 

 to greater and greater depths, and has thus 

 tended to draw the water away from the 

 surface of what are now continental areas.. 

 But if the earth's crust under the ocean has. 

 subsided, it has also been elevated within 

 what are now dry lands again and again. 

 GEIKIE Earth Sculpture, ch. 1, p. 12. (G. P. 

 P., 1898.) 



630. CONTINENTS SUBMERGED AT 

 VARIOUS EPOCHS "The Earth Standing 

 Out of the Water and in the Water." The 

 extensive geographical range of the deriva- 

 tive rocks, most of which are of marine ori- 

 gin, must convince us that the greater por- 

 tion of our continental areas has been under 

 water. It is not to be understood, however, 

 that all the land-surfaces occupied by sedi- 

 mentary strata have been submerged at one 

 and the same time. On the contrary, the 

 several geological systems have been accu- 

 mulated at widely different periods. GEIKIE 

 Earth Sculpture, ch. 1, p. 12. (G. P. P., 

 1898.) 



631. CpNTINUITY OF NATURE A 



Universe without Law, a Universe De- 

 ranged. Probably the most satisfactory 

 way to secure for oneself a just appreciation 

 of the principle of continuity is to try to 

 conceive the universe without it. The oppo- 

 site of a continuous universe would be a dis- 

 continuous universe, an incoherent and ir- 

 relevant universe as irrelevant in all ita 

 ways of doing things as an irrelevant per- 

 son. In effect, to withdraw continuity from 

 the universe would be the same as to with- 

 draw reason from an individual. The uni- 

 verse would run deranged. DBUMMOND 

 Natural Law in the Spiritual World, int., p. 

 34. (H. Al.) 



632. CONTRACTION OF BULK MAY 

 SUSTAIN HEAT OF SUN Gravity the Cause 

 of Heat. If, now, there is no present mani- 

 festation of force sufficient to cover the ex- 

 penditure of the sun's heat, the sun must 

 originally have had a store of heat which it 

 gradually gives out. But whence this store? 

 We know that the cosmical forces alone 

 could have produced it. And here the hypoth- 

 esis, previously discussed as to the origin 

 of the sun, comes to our aid. If the mass of 

 the sun had been once diffused in cosmical 

 space, and had then been condensed that is, 

 had fallen together under the influence of 

 celestial gravity if then the resultant mo- 

 tion had been destroyed by friction and im- 

 pact, with the production of heat, the new 

 world produced by such condensation must 



