363 



SCIENTIFIC SIDE-LIGHTS 



latio 



first the Antilles, then the plains of the 

 Ohio and Mississippi, and lastly the oppo- 

 site coasts of Venezuela or Caracas. Thirty 

 days after the total destruction of the beau- 

 tiful capital of the province there was an 

 eruption of the long inactive volcano of St. 

 Vincent, in the neighboring islands of the 

 Antilles. A remarkable phenomenon accom- 

 panied this eruption; at the moment of this 

 explosion, which occurred on the 30th of 

 April, 1811, a terrible subterranean noise 

 was heard in South America, over a district 

 of more than 35,000 square miles. The in- 

 habitants of the banks of the Apure, at the 

 confluence of the Rio Nula, and those living 

 on the remote seacoast of Venezuela, agreed 

 in comparing this sound to the noise of 

 heavy artillery. The distance from the con- 

 fluence of the Rio Nula with the Apure (by 

 which I entered the Orinoco) to the volcano 

 of St. Vincent, measured in a straight line, 

 is no less than 628 miles. This noise was 

 certainly not propagated through the air, 

 and must have arisen from some deep-seated 

 subterranean cause ; its intensity was, more- 

 over, hardly greater on the shores of the 

 Caribbean Sea, near the seat of the raging 

 volcano, than in the interior of the country 

 in the basin of the Apure and the Orinoco. 

 HUMBOLDT Views of Nature, p. 361. (Bell, 

 1896.) 



1772. ISLANDS OF CORAL Growing 

 in Spite of Beating Surge Advance against 

 Resistance. Of thirty-two of these coral is- 

 lands visited by Beechey in his voyage to the 

 Pacific, twenty-nine had lagoons in their 

 centers. The largest was 30 miles in di- 

 ameter and the smallest less than a mile. 

 All were increasing their dimensions by the 

 active operations of the lithophytes, which 

 appeared to be gradually extending and 

 bringing the immersed parts of their struc- 

 ture to the surface. The scene presented 

 by these annular reefs is equally striking 

 for its singularity and beauty. A strip of 

 land a few hundred yards wide is covered 

 by lofty coconut-trees, above which is the 

 blue vault of heaven. This band of verdure 

 is bounded by a beach of glittering white 

 sand, the outer margin of which is encircled 

 with a ring of snow-white breakers, beyond 

 which are the dark, heaving waters of the 

 ocean. The inner beach encloses the still clear 

 water of the lagoon, resting in its greater 

 part on white sand, and, when illuminated 

 by a vertical sun, of a most vivid green. Cer- 

 tain species of zoophytes abound most in 

 the lagoon, others on the exterior margin 

 where there is a great surf. " The ocean," 

 says Mr. Darwin, " throwing its breakers 

 on these outer shores, appears an invincible 

 enemy, yet we see it resisted and even con- 

 quered by means which at first seem most 

 weak and inefficient. No periods of repose 

 are granted, and the long swell caused by 

 the steady action of the trade-wind never 

 ceases. The breakers exceed in violence 

 those of our temperate regions, and it is 



impossible to behold them without feeling 

 a conviction that rocks of granite or quartz 

 would ultimately yield and be demolished 

 by such irresistible forces. Yet these low, 

 insignificant coral islets stand and are vic- 

 torious, for here another power, as antago- 

 nist to the former, takes part in the con- 

 test. The organic forces separate the atoms 

 of carbonate of lime one by one from the 

 foaming breakers, and unite them into a 

 symmetrical structure; myriads of archi- 

 tects are at work night and day, month 

 after month, and we see their soft and gelat- 

 inous bodies through the agency of the 

 vital laws conquering the great mechanical 

 power of the waves of an ocean, which 

 neither the art of man nor the inanimate 

 works of Nature could successfully resist." 

 LYELL Principles of Geology, bk. iii, ch. 

 50, p. 780. (A., 1854.) 



1773. ISLANDS OF FLOATING SEA- 

 WEED The Sargasso Fauna Floating 

 Homes of Marine Animals. The pelagic 

 zone may be divided into several geograph- 

 ical regions and subregions, which it would 

 be beyond the scope of this book to enumer- 

 ate here, but there is one that calls for a 

 few brief remarks. In many parts of the 

 ocean there may be found vast areas of float- 

 ing seaweed [sargasso] which carry with 

 them a population of Crustacea and other 

 animals peculiarly their own. This Sar- 

 gasso fauna presents so many characteris- 

 tics and so many features different from that 

 of the ordinary pelagic fauna that the tracts 

 of sea bearing this weed must be considered 

 to rank as a special region of the pelagic 

 zone, which may be called the " Sargasso 

 region." HICKSON Fauna of the Deep Sea, 

 ch. 3, p. 48. (A., 1894.) 



1774. ISOLATION OF OUR SUN 



Distance from Alpha Centauri Seventy-five 

 Million Years by Express Train. Our sun, 

 a star in the immensity, is isolated in in- 

 finitude, and the nearest sun reigns at 10 

 trillions of leagues (25 billions of miles) 

 from our terrestrial abode. Notwithstand- 

 ing its unimaginable velocity of 186,400 

 miles a second, light moves, flies, during 

 four years and 128 days to come from this 

 sun to us. Sound would take more than 3 

 millions of years to cross the same abyss. 

 At the constant velocity of 60 kilometers 

 (37 miles) an hour an express train start- 

 ing from the sun Alpha Centauri would 

 not arrive here till after an uninterrupted 

 course of nearly 75 millions of years. 

 FLAMMABION Popular Astronomy, bk. v, ch. 

 5, p. 599. (A.) 



1775. 



Independence of 



Each Sun in Its Own Domain. Thus our 

 sun and the neighboring suns are isolated. 

 Each is an independent king in its own 

 province, and if they feel each other across 

 the infinite, and are subject to the influence 

 of their reciprocal attraction, it is but a 

 suzerainty of little effect. The motions 



