667 



SCIENTIFIC SIDE-LIGHTS 



Summation 

 Sun 



observe an analogous fact in celestial ob- 

 jects. The stars appear animated with mo- 

 tions which draw them apparently towards 

 a certain region of the sky that which is 

 behind us. On each side of us they seem to 

 fly past, and the constellations which are 

 in front of us appear to enlarge so as to 

 open for us a passage. Calculation has 

 shown that these perspective appearances 

 are caused by the translation of the sun, 

 the earth, and all the planets towards a 

 region of the sky marked by the constella- 

 tion Hercules. We travel towards that 

 region with a velocity which it is difficult 

 to determine exactly, but which appears to 

 be from 400 to 500 millions of miles per 

 annum. We leave the starry latitudes where 

 Sirius sparkles, and we sail towards those 

 where shine the stars of Lyra and of Her- 

 cules. The earth has never passed twice 

 over the same course. FLAMMARION Popu- 

 lar Astronomy, bk. i, ch. 5, p. 50. (A.) 



33OO. SUN SUPPOSED TO BE PURE 

 AND QUENCHLESS FIRE Hence the Al- 

 chemists' Quest for an Ever-burning Lamp. 

 To look across the space of over ninety 

 million miles, and to try to learn from that 

 distance the nature of the solar heat, and 

 how it is kept up, seemed to the astronomers 

 of the last century a hopeless task. The 

 difficulty was avoided rather than met by 

 the doctrine that the sun was pure fire, and 

 shone because " it was its nature to." In 

 the Middle Ages such an idea was uni- 

 versal; and along with it, and as a logical 

 sequence of it, the belief was long prevalent 

 that it was possible to make another such 

 flame here, in the form of a lamp which 

 should burn forever and radiate light end- 

 lessly without exhaustion. With the phi- 

 losopher's stone, which was to transmute lead 

 into gold, this perpetual lamp formed a 

 prime object of research for the alchemist 

 and student of magic. 



We recall the use which Scott has made 

 of the belief in this product of " gramarye " 

 in the " Lay of the Last Minstrel," where 

 it is sought to open the grave of the great 

 wizard in Melrose Abbey. It is midnight 

 when the stone which covers it is heaved 

 away, and Michael's undying lamp, buried 

 with him long ago, shines out from the open 

 tomb and illuminates the darkness of the 

 chancel. 



I would you had been there to see 



The light break forth so gloriously; 



That lamp shall burn unquenchably 



Until the eternal doom shall be, 



says the poet. Now we are at liberty to 

 enjoy the fiction as a fiction; but if we 

 admit that the art which could make such 

 a lamp would indeed be a black art, which 

 did not work under Nature's laws, but 

 against them, then we ought to see that, 

 as the whole conception is derived from the 

 early notion of a miraculous constitution 

 of the sun, the idea of an eternal self-sus- 

 tained sun is no more permitted to us than 

 that of an eternal self -sustained lamp. We 



must look for the cause of the sun's heat 

 in Nature's laws. LANGLEY New Astrono- 

 my, ch. 4, p. 91. (H. M. & Co., 1896.) 



33O1. SUN THE SOURCE OF TER- 

 RESTRIAL ENERGY Decay the Recoiling 

 of the Bent Spring. All terrestrial energy 

 comes from the sun, and every manifesta- 

 tion of power on the earth can be traced 

 directly back to his energizing and life-giv- 

 ing rays. The force with which oxygen tends 

 to unite with the other elements may be 

 regarded as a spring, which the sun's rays 

 have the power to bend. In bending this 

 spring they do a certain amount of work, 

 and when, in the process of combustion, the 

 spring flies back, the energy reappears. 

 Moreover, the instability of all organized 

 forms is but a phase of the same action, and 

 the various processes of decay, with the ac- 

 companying phenomenon of death, are sim- 

 ply the recoiling of the same bent spring. 

 Amid all these varied phenomena, the one 

 element which reappears in all, and fre- 

 quently wholly engrosses our attention, is 

 energy. COOKE Neio Chemistry, lect. 10, p. 

 235. (A., 1899.) 



33O2. 



Delicacy as Well 



as Power Due to Central Orb. We have . . . 

 been led to recognize the sun as the ultimate 

 material source of all the energy which we 

 possess, and we must now regard him as 

 the source likewise of all our delicacy of 

 construction. It requires the energy of his 

 high- temperature rays so to wield and ma- 

 nipulate the powerful forces of chemical af- 

 finity, so to balance these various forces 

 against each other, as to produce in the 

 vegetable something which will afford our 

 frames not only energy, but also delicacy 

 of construction. Low - temperature heat 

 would be utterly unable to accomplish this; 

 it consists of ethereal vibrations which are. 

 not sufficiently rapid, and of waves that 

 are not sufficiently short, for the purpose 

 of shaking asunder the constituents of com- 

 pound molecules. It thus appears that ani- 

 mals are, in more ways than one, pensioners 

 upon the sun's bounty. STEWART Conserva- 

 tion of Energy, ch. 6, p. 413. (Hum., 1880.) 



3303. 



Deprivation of 



Sunlight Would Speedily Destroy All Ac- 

 tivity on Earth. When we come to in- 

 quire for the source of the energy which 

 lifts the water from the sea to the moun- 

 tain-top, which decomposes the carbonic 

 acid of the atmosphere and plant-foods of 

 the soil, and builds up the hydrocarbons 

 and other fuels of animal and vegetable tis- 

 sue, we find it always mainly in the solar 

 rays. I say mainly, because, of course, the 

 light and heat of the stars, the impact of 

 meteors, and the probable slow contraction 

 of the earth, are all real sources of energy, 

 and contribute their quota. But, as com- 

 pared with the energy derived from the sun, 

 their total amount is probably something 

 like the ratio of starlight to sunlight; so 



