lotion 

 [ound-builder's 



SCIENTIFIC SIDE-LIGHTS 



462 



one sensation or feeling is transformed into 

 a second. But no system of cosmiq mechan- 

 ics can make plain to us how a motion can 

 pass over into a sensation or feeling. 

 WUNDT Psychology, lect. 1, p. 6. (Son. & 

 Co., 1896.) 



2264. MOTION OF STARS AND 

 WORLDS HARMONIOUS A Shower of Stars 

 Pettiness of Merely Personal and Selfish 

 Life. Thus perpetual motion bears the 

 world along! The sun moves through 

 space; the earth moves round him, letting 

 herself be carried along in his flight; the 

 moon moves, circulating round us, while we 

 gravitate round the radiant hearth which 

 precipitates itself into the eternal void. 

 Like a shower of stars the worlds whirl, 

 borne along by the winds of heaven, and are 

 carried down through immensity; suns, 

 earths, satellites, comets, shooting stars, 

 humanities, cradles, graves, atoms of the in- 

 finite, seconds of eternity, perpetually 

 transform beings and things; all move on, 

 all wing their flight under the breath divine 

 while trade goes on, or the investor counts 

 his gold and piles it up, believing that he 

 holds the entire universe in his casket. O 

 folly of terrestrial manikins! folly of busy 

 merchants, folly of the miser, folly of the 

 suitor, folly of the pilgrim to Mecca or to 

 Lourdes, folly of the blind ! When shall the 

 inhabitant of the earth open his eyes to see 

 where he is, to live the life of the mind, and 

 to base his happiness on intellectual con- 

 templations? When shall he throw off the 

 old man, the animal cover, to free himself 

 from the fetters of the flesh and soar in the 

 heights of knowledge? FLAMMARION Popu- 

 lar Astronomy, bk. ii, ch. 3,, p. 109. (A.) 



2265. MOTION OF STARS DETER- 

 MINED Spectroscopic Evidence of Approach 

 or Recession. If the star is approaching or 

 receding, the motion is reflected in the spec- 

 trum in a singular way. Let us suppose 

 that it approaches. The lengths of the 

 waves, which give rise to the diversity of 

 colors, diminish, and the refrangibility of 

 each color increases. If, then, we observe 

 with a spectroscope two luminous sources, 

 the one fixed ( the electric tube ) , the other 

 moving (the star), both giving, for example, 

 the line (" D ") so characteristic of sodium, 

 we see in the two superposed spectra the 

 rays of this metal, which will not coincide. 

 The line D shown by the spectrum of the 

 star will deviate from the line D shown by 

 the tube, and the displacement will be to- 

 wards the violet end if the star is ap- 

 proaching the earth, and towards the red 

 end if it is receding. The difference will 

 serve not only to ascertain whether the star 

 is approaching or receding, but even to de- 

 termine the velocity. FLAMMARION Popular 

 Astronomy, bk. vi, ch. 9, p. 648. (A.) 



2266 MOTION PRODUCED BY HEAT 



Reconverted into Heat Steam the Me- 

 dium of Change. Those who have walked 

 through the workshops of Woolwich, or 



through any of our great factories where 

 machinery is extensively employed, will 

 have been sufficiently impressed with the 

 aid which the mighty power of heat renders 

 to man. Let it be remembered that every 

 wheel which revolves, every chisel, and 

 plane, and punch, which passes through 

 solid iron as if it were so much cheese, de- 

 rives its moving energy from the clashing 

 atoms in the furnace. The motion of these 

 atoms is communicated to the boiler, thence 

 to the water, whose molecules are shaken 

 asunder, flying from each other with a repel- 

 lent energy commensurate with the heat 

 communicated. The steam is simply the ap- 

 paratus, through the intermediation of 

 which the atomic motion is converted into 

 mechanical motion. And the motion thus 

 generated always, in the long run, repro- 

 duces its parent. Look at the planing-tools 

 and boring-instruments streams of water 

 gush over them to keep them cool. Take up 

 the curled iron shavings which the planing- 

 tool has pared off; you cannot hold them in 

 your hand, they are so hot. Here the mov- 

 ing force is restored to its first form; the 

 energy of the machine has been consumed in 

 reproducing the power from which that 

 energy was derived. TYNDALL Heat a Mode 

 of Motion, lect. 6, p. 165. (A., 1900.) 



2267. MOTION TRANSFORMED INTO 



HEAT Heat Is Molecular Motion Constancy 

 of Force. In firing a ball against a target 

 the projectile, after collision, is often found 

 hot. Mr. Fairbairn informs me that in the 

 experiments at Shoeburyness it is a common 

 thing to see a flash, even in broad daylight, 

 when the ball strikes the target. And if 

 our lead weight be examined after it has 

 fallen from a height it is also found heated. 

 . . . When a violin bow is drawn across 

 a string, the sound produced is due to mo- 

 tion imparted to the air, and to produce 

 that motion muscular force has been ex- 

 pended. We may here correctly say that the 

 mechanical force of the arm is converted 

 into music. In a similar way we say that 

 the arrested motion of our _ descending 

 weight, or of the cannon-ball, is converted 

 into heat. The mode of motion changes, but 

 motion still continues; the motion of the 

 mass is converted into a motion of the atoms 

 of the mass; and these small motions, com- 

 municated to the nerves, produce the sen- 

 sation we call heat. TYNDALL Fragments of 

 Science, vol. i, ch. 16, p. 371. (A., 1897.) 



2268. MOTION, VIBRATION, AND 

 HARMONY PERVADE ALL NATURE Cor- 

 respondence of Music and Color. A univer- 

 sal motion bears along the stars, atoms of 

 the infinite. The moon gravitates round the 

 earth, the earth gravitates round the sun, 

 the sun carries along all its planets and 

 their satellites towards the constellation 

 Hercules; and these motions are executed 

 according to determined laws, like the hand 

 of a watch which turns round its center, and 

 like the circular undulations which are de- 



