Glaciers 

 God's 



SCIENTIFIC SIDE-LIGHTS 



284 



the larger and deeper valleys to regions far 

 below the general snow-line. To these it 

 slowly finds its way in the form of rivers 

 of ice, called glaciers, the consolidation of 

 which is produced by pressure and by the 

 congelation of water infiltered into the por- 

 ous mass, which is always undergoing par- 

 tial liquefaction, and receiving in summer 

 occasional showers of rain on its surface. 

 In a day of hot sunshine or mild rain, in- 

 numerable rills of pure and sparkling water 

 run in icy channels along the surface of the 

 glaciers, which in the night shrink and 

 come to nothing. They are often precipi- 

 tated in bold cascades into deep fissures in 

 the ice, and contribute together with springs 

 to form torrents, which flow in tunnels at 

 the bottom of the glaciers for many a league, 

 and at length issue at their extremities from 

 beneath beautiful caverns or arches. The 

 waters of these streams are always densely 

 charged with the finest mud, produced by 

 the grinding of rock and sand under the 

 weight of the moving mass. LYELL Prin- 

 ciples of Geology, bk. ii, ch. 15, p. 222. (A., 

 1854.) 



1381. GLACIERS NOW IN ACTION 



Present Agree with Ancient Results Con- 

 tinuity of Nature. Certainly, no one fa- 

 miliar with the facts could suppose that 

 floating ice or icebergs had abraded, pol- 

 ished, and furrowed the bottom of narrow 

 valleys as we find them worn, polished, and 

 grooved by glaciers. And it must be remem- 

 bered that this is a theory founded not upon 

 hypothesis, but upon the closest comparison. 

 I have not become acquainted with these 

 marks in regions where glaciers no longer 

 exist, and made a theory to explain their 

 presence. I have, on the contrary, studied 

 them where they are in process of forma- 

 tion. I have seen the glacier engrave its 

 lines, plow its grooves and furrows in 

 the solid rock, and polish the surfaces over 

 which it moved, and was familiar with all 

 this when I found afterwards appearances 

 corresponding exactly to those which I had 

 investigated in the home of the present gla- 

 ciers. I could therefore say, and I think 

 with some reason, that " this also is the 

 work of the glacier acting in ancient times 

 as it now acts in Switzerland." AGASSIZ 

 Geological Sketches, ser. ii, p. 39. (H. M. 

 & Co., 1896.) 



1382. GLASS-MAKING IN NATURE'S 

 LABORATORIES But when the lava con- 

 tains no ready-formed crystals, but consists 

 entirely of a glassy substance in a more 

 or less perfect state of fusion, the liberation 

 of steam gives rise to the formation of the 

 beautiful material known as " pumice." 

 Pumice consists of a mass of minute glass 

 bubbles ; these bubbles have not usually, how- 

 ever, retained their globular form, but have 

 been elongated in one direction through the 

 movement of the mass while it was still in a 

 plastic state. JUDD Volcanoes, ch. 4, p. 68. 

 (A., 1899.) 



1383. GLORY, REFLECTED The Light 

 of Planets Not Their Own. Our ancestors 

 were far from imagining that these lumi- 

 nous points wandering among the stars do 

 not possess any real light of their own; that 

 they are dark like the earth, and as large 

 as she is; that several are even much larger 

 and heavier than our world; that they are 

 illuminated by the sun, like the earth and 

 moon, neither more nor less; that their dis- 

 tance is small compared to that which sepa- 

 rates us from the stars; that they form, 

 with the earth, a family of which the sun 

 is the father! Yes, that luminous point, 

 for example, which shines like a star is 

 Jupiter. It has itself no light, any more 

 than the earth has, but it is illuminated by 

 the sun; and as the earth shines from afar 

 on account of this illumination, so it shines 

 a luminous point in which is condensed all 

 the light scattered over its immense disk. 

 Place a stone on a black cloth in a chamber 

 completely closed to the daylight, throw 

 upon it the rays of the sun by means of 

 an opening suitably arranged, and this stone 

 will shine like the moon and like Jupiter. 

 The planets are dark worlds like ours, and 

 only shine by the solar light which they re- 

 ceive and reflect into space. FLAMMAKIOX 

 Popular Astronomy, bk. iv, ch. l,p. 330. (A.) 



1384. GLORY VEILED FOR HUMAN 

 WEAKNESS Blinding Effect of Sun's Light 

 Overcome Polarizing Eyepiece. The pro- 

 jecting apparatus is next removed and re- 

 placed by the polarizing eyepiece. Sir 

 William Herschel used to avoid the blinding 

 effects of the concentrated solar light by 

 passing the rays through ink and water, 

 but the phenomena of " polarization " have 

 been used to better advantage in modern 

 apparatus. [In this instrument] the light 

 is polarized with three successive reflections 

 through three tubes. By its aid the eye can 

 be safely placed where the concentrated heat 

 would otherwise melt iron. In practise I 

 have often gazed through it at the sun's 

 face without intermission from four to five 

 hours, with no more fatigue or harm to the 

 eye than in reading a book. By its aid the 

 observer fills in the outline already pro- 

 jected on the paper. LANGLEY New As- 

 tronomy, ch. 1, p. 18. (H. M. & Co., 1896.) 



1385. GOD CAN REVEAL HIMSELF 



TO MAN Intuitive Perception of the Divine. 

 The existence of a Being from whom our 

 own being has been derived involves, at 

 least, the possibility of some communication 

 direct or indirect. Yet the impossibility or 

 the improbability of any such communica- 

 tion is another of the assumptions contin- 

 ually involved in current theories about the 

 origin of religion. Yet it is quite certain 

 that no such assumption can be reasonably 

 made. The perceptions of the human mind 

 are accessible to the intimations of exter- 

 nal truth through many avenues of ap- 

 proach. In its very structure it is made to 

 be responsive to some of these intimations 



