107 



SCIENTIFIC SIDE-LIGHTS 



hlng 



greater distance from the equator in the 

 southern hemisphere than in the northern, 

 being found even as far as 46 S. latitude in 

 New Zealand. There is little doubt that 

 this is owing to the more uniform and moist 

 climate occasioned by the greater propor- 

 tional area of sea. LYELL Principles of Ge- 

 ology, ch. 6, p. 87. (A., 1854.) 



529. CODE OF HONOR Permissions of 

 Moral Evil. What may be called " club 

 opinion " is one of the very strongest forces 

 in life. The thief must not steal from other 

 thieves ; the gambler must pay his gambling 

 debts, tho he pay no other debts in the 

 world. The code of honor of fashionable so- 

 ciety has throughout history been full of 

 permissions as well as of vetoes, the only 

 reason for following either of which is that 

 so we best serve one of our social selves. 

 You must not lie in general, but you may 

 lie as much as you please if asked about 

 your relations with a lady; you must ac- 

 cept a challenge from an equal, but if chal- 

 lenged by an inferior you may laugh him to 

 scorn : these are examples of what is meant. 

 JAMES Psychology, vol. i, ch. 10, p. 295. 

 (H. II. & Co., 1899.) 



530. COINCIDENCE OF GREAT DIS- 

 COVERIES Columbus and Copernicus. The 

 age of Columbus, Gama, and Magellan the 

 age of great maritime enterprises coin- 

 cided in a most wonderful manner with 

 many great events, with the awakening of 

 a feeling of religious freedom, with the de- 

 velopment of nobler sentiments for art, and 

 with the diffusion of the Copernican views 

 regarding the system of the universe. 

 Nicolaus Copernicus had already attained 

 his twenty-first year, and was engaged in 

 making observations with the astronomer 

 Albert Brudzewski, at Cracow, when Colum- 

 bus discovered America. Hardly a year 

 after the death of the great discoverer, and 

 after a six years' residence at Padua, Bo- 

 logna, and Rome, we find him returned to 

 Cracow, and busily engaged in bringing 

 about a thorough revolution in the astro- 

 nomical views of the universe. . . . He 

 was nominated, in 1510, canon of Frauen- 

 burg, where he labored for thirty-three 

 years on the completion of his work, en- 

 titled " De Revolutionibus Orbium Coeles- 

 tium." The first printed copy was brought 

 to him when, shattered in mind and body, he 

 was preparing himself for death. He saw it 

 and touched it, but his thoughts were no 

 longer fixed on earthly things, and he died 

 several days afterward (on the 24th of May, 

 1543). HUMBOLDT Cosmos, vol. ii, pt. ii, p. 

 303. (H., 1897.) 



531. 



Moons of Jupiter 



Simultaneously Discovered. The moons of 

 Jupiter, the first of all the secondary plan- 

 ets discovered by the telescope, were first 

 seen, almost simultaneously and wholly in- 

 dependently, on the 29th of December, 1609, 

 by Simon Marius at Ansbach, and on the 



7th of January, 1610, by Galileo at Padua. 

 In the publication of this discovery, Galileo, 

 by the "Nuncius Siderius" (1610), preceded 

 the " Mundus Jovialis " (1614) of Simon 

 Marius. . . . 



The discovery of Jupiter's satellites 

 marks an ever memorable epoch in the his- 

 tory and the vicissitudes of astronomy. The 

 occultations of the satellites, or their en- 

 trance into Jupiter's shadow, led to a knowl- 

 edge of the velocity of light (1675), and, 

 through this knowledge, to the explanation 

 of the aberration-ellipse of the fixed stars 

 (1727), in which the great orbit of the 

 earth, in its annual course round the sun, 

 is, as it were, reflected on the vault of 

 heaven. These discoveries of Romer and 

 Bradley have been justly termed " the key- 

 stone of the Copernican system," the per- 

 ceptible evidence of the translatory motion 

 of the earth. HUMBOLDT Cosmos, vol. ii, pt. 

 ii, pp. 320, 322. (H., 1897.) 



532. COLOR, ABSENCE OF, HELPFUL 

 AT A CERTAIN STAGE Advantages of 

 the Glass Animals in the Struggle for Ex- 

 istence. Evidently for all glass animals, 

 carrying on their unceasing warfare, their 

 waterlike bodily composition is of the great- 

 est utility. The pursuers can approach their 

 prey without being observed, the pursued 

 are able more easily to escape than if both 

 were colored and wanting in transparency, 

 and therefore more readily visible in clear 

 water. Suppose we assume that of these 

 glass animals different varieties existed 

 originally, varying especially in the degree 

 of transparency and want of color. Then, 

 certainly, those individuals that were most 

 transparent and colorless would achieve the 

 preponderance in the struggle for existence, 

 at the same time confirming and strengthen- 

 ing those advantageous individual peculiari- 

 ties for generations, and finally arrive at a 

 perfectly glasslike development. HAECKEL 

 Generelle Morphologic, vol. ii, p. 243. 

 (Translated for Scientific Side-Lights.) 



533. COLOR A NEGATIVE QUALITY 



Produced by Subtraction, Not by Addi- 

 tion. Pass a black ribbon through the col- 

 ors of the spectrum; it quenches all of 

 them. The meaning of blackness is thus 

 revealed it is the result of the absorption 

 of all the constituents of solar light. Pass 

 a red ribbon through the spectrum. In the 

 red light the ribbon is a vivid red. Why? 

 Because the light that enters the ribbon is 

 not quenched or absorbed, but in great part 

 sent back to the eye. Place the same ribbon 

 in the green of the spectrum ; it is black as 

 jet. It absorbs the green light, and leaves 

 the space on which it falls a space of intense 

 darkness. Place a green ribbon in the green 

 of the spectrum. It shines vividly with its 

 proper color; transfer it to the red, it is 

 black as jet. Here it absorbs all the light 

 that falls upon it, and offers mere darkness 

 to the eye. Thus, when white light is em- 

 ployed, the red sifts it by quenching the 



