653 



SCIENTIFIC SIDE-LIGHTS 



Steam-jets 

 Stone 



animals that live in more lively water. 

 HICKSON Fauna of the Deep Sea, ch. 2, p. 

 34. (A., 1894.) 



323O. Strata Deposited 



by Currents. It appears extraordinary that 

 in some tracts of the sea adjoining the coast 

 of England, where we know that currents 

 are not only sweeping along rocky masses, 

 thrown down from time to time from the 

 high cliffs, but also occasionally scooping 

 out channels in the regular strata, there 

 should exist fragile shells and tender zoo- 

 phytes in abundance, which live uninjured 

 by these violent movements. The ocean, 

 however, is in this respect a counterpart 

 of the land ; and as, on the continents, rivers 

 may undermine their banks, uproot trees, 

 and roll along sand and gravel, while their 

 waters are inhabited by testaceans and fish, 

 and their alluvial plains are adorned with 

 rich vegetation and forests, so the sea may 

 be traversed by rapid currents, and its bed 

 may here and there suffer great local de- 

 rangement, without any interruption of the 

 general order and tranquillity. It has been 

 ascertained by soundings in all parts of the 

 world that where new deposits are taking 

 place in the sea coarse sand and small 

 pebbles commonly occur near the shore, 

 while farther from land and in deeper wa- 

 ter finer sand and broken shells are spread 

 out over the bottom. Still farther out the 

 finest mud and ooze are alone met with. 

 Mr. Austen observes that this rule holds 

 good in every part of the English Channel 

 examined by him. He also informs us that 

 where the tidal current runs rapidly in what 

 are called " races," where surface undula- 

 tions are perceived in the calmest weather, 

 over deep banks, the discoloration of the 

 water does not arise from the power of such 

 a current to disturb the bottom at a depth 

 of 40 or 80 fathoms, as some have supposed. 

 In these cases a column of water sometimes 

 500 feet in height is moving onwards with 

 the tide clear and transparent above, while 

 the lower portion holds fine sediment in sus- 

 pension (a fact ascertained by soundings), 

 when suddenly it impinges upon a bank, and 

 its height is reduced to 300 feet. It is thus 

 made to boil up and flow off at the sur- 

 face, a process which forces up the lower 

 strata of water charged with fine particles 

 of mud, which in their passage from the coast 

 had gradually sunk to a depth of 300 feet 

 or more. LYELL Principles of Geology, bk. 

 ii, ch. 21, p. 341. (A., 1854.) 



3231. STILLNESS OF TROPIC NOON 



Jet Busy Life. A singular contrast to the 

 scenes I have here described [the uproar 

 of a tropical forest by night], and which I 

 had repeated opportunities of witnessing, 

 is presented by the stillness which reigns 

 within the tropics at the noontide of a 

 day unusually sultry. ... A thermom- 

 eter observed in the shade, but brought 

 within a few inches of the lofty mass of 

 granite rock, rose to more than 122 F. 



All distant objects had wavy, undulating 

 outlines, the optical effect of the mirage. 

 Not a breath of air moved the dust-like 

 sand. The sun stood in the zenith, and 

 the effulgence of light poured upon the river, 

 and which, owing to a gentle ripple of the 

 waters, was brilliantly reflected, gave addi- 

 tional distinctness to the red haze which 

 veiled the distance. All- the rocky mounds 

 and naked boulders were covered with large, 

 thick-scaled iguanas, gecko-lizards, and spot- 

 ted salamanders. Motionless, with uplifted 

 heads and widely extended mouths, they 

 seemed to inhale the heated air with ec- 

 stasy. The larger animals at such times 

 take refuge in the deep recesses of the for- 

 est, the birds nestle beneath the foliage of 

 the trees or in the clefts of the rocks; but 

 if in this apparent stillness of Nature we 

 listen closely for the faintest tones, we 

 detect a dull, muffled sound, a buzzing and 

 humming of insects close to the earth, in 

 the lower strata of the atmosphere. Every- 

 thing proclaims a world of active organic 

 forces. In every shrub, in the cracked bark 

 of trees, in the perforated ground inhabited 

 by hymenopterous insects, life is everywhere 

 audibly manifest. It is one of the many 

 voices of Nature revealed to the pious and 

 susceptible spirit of man. HUMBOLDT Views 

 of Nature, p. 200. (Bell, 1896.) 



3232. STIMULUS AND INCITEMENT 



The Teacher's Great Work. My theory 

 of education agrees with that of Emer- 

 son, according to which instruction is 

 only half the battle, what he calls provoca- 

 tion being the other half. By this he means 

 that power of the teacher, through the force 

 of his character and the vitality of his 

 thought, to bring out all the latent strength 

 of his pupil, and to invest with interest 

 even the driest matters of detail. TYNDALL 

 Forms of Water, pref., p. 17. (A., 1899.) 



3233. STONE AGE, UNIVERSALITY 



OF Fantastic Explanations of Forgotten Im- 

 plements Everywhere Man Has Risen Only 

 by Toil and Struggle. One of the chief ques- 

 tions to be asked about the condition of any 

 people is whether they have metal in use 

 for their tools and weapons. If so, they may 

 be said to be in the metal age. If they have 

 no copper or iron, but make their hatchets, 

 knives, spear-heads, and other cutting and 

 piercing instruments of stone, they are said 

 to be in the Stone Age. Wherever such 

 stone implements are picked up, as they 

 often are in our own plowed fields, they 

 prove that Stone- Age men have once dwelt 

 in the land. It is an important fact that 

 in every region of the inhabited world an- 

 cient stone implements are thus found in 

 the ground, showing that at some time 

 the inhabitants were in this respect like 

 the modern savages. In countries where the 

 people have long been metal-workers they 

 have often lost all memory of what these 

 stone things are, and tell fanciful stories 

 to account for their being met with in 



