gain 

 eason 



SCIENTIFIC SIDE-LIGHTS 



572 



again attained by rotted rock testifies like- 

 wise to the destructive action of rain-water 

 percolating from the surface. GEIKIE Earth 

 Sculpture, ch. 2, p. 25. (G. P. P., 1898.) 



2822. RAINBOW, NO PERFECT 

 IMAGE OF IN WATER Seeing two [rain- 

 bows], the one in the heavens, the other in 

 the water, you might be disposed to infer 

 that the one bears the same relation to the 

 other that a tree upon the water's edge 

 bears to its reflected image. The rays, how- 

 ever, which reach an observer's eye after re- 

 flection, and which form a bow, would, were 

 their course uninterrupted, converge to a 

 point vertically under the observer, and as 

 far below the level of the water as his eye 

 is above it. But under no circumstances 

 could an eye above the water-level, and one 

 below it, see the same bow in other words, 

 the selfsame drops of rain cannot form the 

 reflected bow and the bow seem directly in 

 the heavens. The reflected bow, therefore, 

 is not, in the usual optical sense of the 

 term, the image of the bow seen in the sky. 

 TYNDALL Lectures on Light, lect. 1, p. 26. 

 (A., 1898.) 



2823. RANGE OF THE CONDOR 



A Run Necessary for Flight A Palisade 

 Trap. This bird [the condor], which, singu- 

 larly enough, like the lamas, vicunas, al- 

 pacas, and guanftcos, is not found beyond 

 the equator in New Granada, penetrates as 

 far south as the Straits of Magellan. In 

 Chile, as in the elevated plateaux of Quito, 

 the condors, which usually live in pairs, or 

 even alone, congregate in flocks for the pur- 

 pose of attacking lambs and calves, or seiz- 

 ing on young guanacos ( guanacillos ) . The 

 havoc annually committed by the condor 

 among the herds of sheep, goats, and cattle, 

 as well as among the wild vicunas, alpacas, 

 and guanacos of the chain of the Andes, is 

 very considerable. The Chileans assert that 

 this bird when in captivity can endure hun- 

 ger for forty days; when in a free state, 

 however, its voracity is excessive, and it 

 then, like the vulture, feeds by preference 

 on carrion. 



The mode of catching these birds, by an 

 enclosure of palisades, ... is as suc- 

 cessful in Chile as in Peru; for the bird, after 

 being rendered heavy from excess of food, is 

 obliged to run a short distance with half- 

 extended wings before it can take flight. A 

 dead ox, which is already in an incipient 

 state of decomposition, is strongly enclosed 

 with palisades, within which narrow space 

 the condors throng together; being unable, 

 as already observed, to fly on account of the 

 excess of food which they have devoured, 

 and impeded in their run by the palisades, 

 these birds are either killed by the natives 

 with clubs, or are caught alive by the lasso. 

 The condor was represented as a symbol of 

 strength on the coinage of Chile immediately 

 after the first declaration of political inde- 

 pendence. HUMBOLDT Views of Nature, p. 

 239. (Bell, 1896.) 



2824. RAYS OF STARS Splendor of 



the Heavens Increased by Optical Illusion. 

 The rays of the stars disappear when the 

 image of the radiating star is seen through 

 a very small aperture made with a needle 

 in a card, and I have myself frequently ob- 

 served both Canopus and Sirius in this man- 

 ner. The same thing occurs in telescopic 

 vision through powerful instruments, when 

 the stars appear either as intensely lumi- 

 nous points, or as exceedingly small disks. 

 Altho the fainter scintillation of the fixed 

 stars in the tropics conveys a certain im- 

 pression of repose, a total absence of stel- 

 lar radiation would, in my opinion, impart 

 a desolate aspect to the firmament, as seen 

 by the naked eye. Illusion of the senses, 

 optical illusion, and indistinct vision, proba- 

 bly tend to augment the splendor of the 

 luminous canopy of heaven. HUMBOLDT Cos- 

 mos, vol. iii, p. 128. (H., 1898.) 



2825. REACTION OF ENVIRON- 

 MENT ON MAN Physical Influences Have 

 Menial Results. The knowledge of the char- 

 acter of Nature in different regions is most 

 intimately associated with the history of 

 the human race and its mental culture. 

 For altho the dawn of this culture cannot 

 have been determined solely by physical in- 

 fluence, climatic relations have at any rate 

 to a great extent influenced its direction, as 

 well as the character of nations, and the 

 degree of gloom or cheerfulness in the dispo- 

 sitions of men. How powerfully did the 

 skies of Greece act on its inhabitants ! Was 

 it not among the nations who settled in the 

 beautiful and happy region between the Eu- 

 phrates, the Halys, and the ^Egean Sea that 

 social polish and gentler feelings were first 

 awakened? and was it not from these genial 

 climes that our forefathers, when religious 

 enthusiasm had suddenly opened to them the 

 Holy Lands of the East, brought back to 

 Europe, then relapsing into barbarism, the 

 seeds of a gentler civilization ? The poetical 

 works of the Greeks and the ruder songs 

 of the primitive northern races owe much 

 of their peculiar character to the forms of 

 plants and animals, to the mountain-valleys 

 in which their poets dwelt, and to the air 

 which surrounded them. To revert to more 

 familiar objects, who is there that does not 

 feel himself differently affected beneath the 

 embowering shade of the beechen grove, or 

 on hills crowned with a few scattered pines, 

 or in the flowering meadow where the breeze 

 murmurs through the trembling foliage of 

 the birch? A feeling of melancholy, or so- 

 lemnity, or of light, buoyant animation is 

 in turn awakened by the contemplation of 

 our native trees. This influence of the phys- 

 ical on the moral world this mysterious 

 reaction of the sensuous on the ideal gives 

 to the study of Nature, when considered 

 from a higher point of view, a peculiar 

 charm which has not hitherto been suffi- 

 ciently recognized. HUMBOLDT Views of Na- 

 ture, p. 219. (Bell, 1896.) 



