95 



SCIENTIFIC SIDE-LIGHTS 



Change 

 Changes 



Granite [is] a rock believed to be of deep- 

 seated origin. Its Plutonic character is 

 evinced not less by its composition and 

 structure than by its relation to the rock- 

 masses that surround it. Every mass of 

 granite, then, has cooled and consolidated, 

 probably very slowly, and certainly at a less 

 or greater depth in the earth's crust. When 

 this rock is met with over a wide area at 

 the actual surface, therefore forming, it 

 may be, great mountains or rolling and 

 broken lowlands we know that in such re- 

 gions thick masses of formerly overlying 

 rocks have been removed. The granite ap- 

 pears at the surface simply because the cov- 

 ering of rocks underneath which it cooled 

 and solidified has been subsequently carried 

 away. GEIKIE Earth Sculpture, ch. 1, p. 16. 

 (G. P. P., 1898.) 



470. CHANGE THE CONDITION OF 

 LIFE Repose of the Earth Will Be Its Death. 

 As long as our planet yields less heat to 

 space than she receives from the bodies of 

 space, so long will the forms upon her sur- 

 face undergo mutation, and as soon as 

 equilibrium, in regard to heat, has been es- 

 tablished we shall have, as Thomson has 

 pointed out, not peace, but death. Life is 

 the product and accompaniment of change, 

 and the selfsame power that tears the 

 flanks of the hills to pieces is the main- 

 spring of the animal and vegetable worlds. 

 Still there is something chilling in the con- 

 templation of the irresistible and remorse- 

 less character of those infinitesimal forces, 

 whose integration through the ages pulls 

 down even the Matterhorn. Hacked and 

 hurt by time, the aspect of the mountain 

 from its higher crags saddened me. Hitherto 

 the impression that it made was that of sav- 

 age strength, but here we had inexorable de- 

 cay. TYNDALL Hours of Exercise in the 

 Alps, ch. 24, p. 291. (A., 1898.) 



471. CHANGE, UNCEASING, OF THE 

 "SOLID EARTH" Continents Rising beneath 

 Our Feet " Thou Renewest the Face of the 

 Earth" ( Ps. civ, 30). It is certain that dur- 

 ing the enormous periods of time of which 

 the records have been discovered by the 

 geologist there have always been continents 

 and oceans upon the earth's surface, just as 

 at present, and it is almost equally certain 

 that the proportions of the earth's surface 

 occupied by land and water, respectively, 

 have not varied very widely from those 

 which now prevail. But, at the same time, 

 it is an equally well-established fact that 

 the denuding forces ever at work upon the 

 earth's surface would have been competent 

 to the removal of existing continents many 

 times over, in the vast periods covered by 

 geological records. Hence we are driven to 

 conclude that the subterranean movements 

 have in past times entirely compensated for 

 the waste produced by the denuding forces 

 ever at work upon our globe. But this is 

 not all. The subterranean forces not only 

 produce upheaval; in a great many cases 



the evidences of subsidence are as clear and 

 conclusive as are those of upheaval in oth- 

 ers. Hence we are driven to conclude that 

 the forces producing upheaval of portions of 

 the earth's crust are sufficient, not only to 

 balance those producing subsidence, but also 

 to compensate for the destructive action of 

 denuding agents upon the land-masses of 

 the globe. JUDD Volcanoes, ch. 10, p. 286. 

 (A., 1899.) 



472. CHANGE, UNSEEN, INVOLVES 

 LIFE OR DEATH Fish Drown* in Airless 

 Water. If a fish be placed in cooked water 

 it swims for a while with its mouth at the 

 surface, for just there is a film that is reac- 

 quiring its charge of oxygen, etc., by ab- 

 sorbing it from the air; but this film is so 

 thin, and so poorly charged, that after a 

 short struggle the fish dies for lack of oxy- 

 gen in its blood ; drowned as truly and com- 

 pletely as an air-breathing animal when im- 

 mersed in any kind of water. WILLIAMS 

 Chemistry of Cookery, ch. 2, p. 10. (A., 

 1900.) 



473. CHANGE WROUGHT BY NINE- 

 TEENTH CENTURY Practical Application 

 of Science Slow Progress in Moral and 

 Social Life. The close of the nineteenth 

 century offers one of the most remarkable 

 spectacles to the thoughtful observer. All 

 educated people are agreed that it has in 

 many respects immeasurably outstripped its 

 predecessors, and has achieved tasks that 

 were deemed impracticable at its commence- 

 ment. An entirely new character has been 

 given to the whole of our modern civilization, 

 not only by our astounding theoretical prog- 

 ress in sound knowledge of Nature, but also 

 by the remarkably fertile practical applica- 

 tion of that knowledge in technical science, 

 industry, commerce, and so forth. On the 

 other hand, however, we have made little or 

 no progress in moral and social life, in com- 

 parison with earlier centuries; at times 

 there has been serious reaction. And from 

 this obvious conflict there have arisen, not 

 only an uneasy sense of dismemberment and 

 falseness, but even the danger of grave cat- 

 astrophes in the political and social world. 

 It is. then, not merely the right, but the 

 sacred duty, of every honorable and humani- 

 tarian thinker to devote himself conscien- 

 tiously to the settlement of that conflict, 

 and to warding off the dangers that it 

 brings in its train. HAECKEL Riddle of the 

 Universe, ch. 1, p. 1. (H., 1900.) 



474. CHANGES AMONG THE STARS 



Increase and Decrease of Brightness. In 

 this long and careful series of observations 

 it has been remarked that the stars are not 

 fixed or unalterable, as they appear to be. 

 There are some which since the time of Hip- 

 parchus have slowly diminished in bright- 

 ness, and have even ended by becoming com- 

 pletely extinct. There are others whose light 

 has gradually increased, and which are now 

 much brighter than they were formerly. 



