683 



SCIENTIFIC SIDE-LIGHTS 



Temperature 

 Tests 



the movement of the earth, and longs to 

 hear with his own ear the subterranean 

 sounds which he has hitherto considered 

 fabulous. With levity he treats the appre- 

 hension of a coming convulsion, and laughs 

 at the fears of the natives; but as soon as 

 his wish is gratified he is terror-stricken, 

 and is involuntarily prompted to seek safety 

 in flight." HUMBOLDT Cosmos, vol. i, p. 215. 

 (H., 1897.) 



3378. TERROR OF HAWK OVER- 

 POWERS MULTITUDES OF BIRDS The 



sudden appearance overhead of this hawk 

 [the marsh-hawk] produces an effect won- 

 derful to witness. I have frequently seen 

 all the inhabitants of a marsh struck with 

 panic, acting as if demented, and suddenly 

 grown careless to all other dangers; and 

 on such occasions I have looked up confident 

 of seeing the sharp-winged death suspended 

 above them in the sky. All birds that hap- 

 pen to be on the wing drop down as if shot 

 into the reeds or water; ducks away from 

 the margin stretch out their necks hori- 

 zontally and drag their bodies, as if wound- 

 ed, into closer cover; not one bird is found 

 bold enough to rise up and wheel about the 

 marauder a usual proceeding in the case 

 of other hawks ; while, at every sudden stoop 

 the falcon makes, threatening to dash down 

 on his prey, a low cry of terror rises from 

 the birds beneath; a sound expressive of an 

 emotion so contagious that it quickly runs 

 like a murmur all over the marsh, as if a 

 gust of wind had swept moaning through 

 the rushes. As long as the falcon hangs 

 overhead, always at a height of about forty 

 yards, threatening at intervals to dash down, 

 this murmuring sound, made up of many 

 hundreds of individual cries, is heard swell- 

 ing and dying away, and occasionally, when 

 he drops lower than usual, rising to a sharp 

 scream of terror. HUDSON Naturalist in La 

 Plata, ch. 5, p. 97. (C. & H., 1895.) 



3379. TERROR OF THE NATIONS 

 PASSES HARMLESSLY B Y Earth Wrapped 

 for Hours in the Tail of a Comet. On June 

 30, 1861, the earth passed, for the second 

 time in this century, through the tail of a 

 great comet. Many of our readers must re- 

 member the unexpected disclosure, on the 

 withdrawal of the sun below the horizon on 

 that evening, of an object so remarkable as 

 to challenge universal attention. A golden- 

 yellow planetary disk, wrapt in dense nebu- 

 losity, shone out while the June twilight 

 of these latitudes was still in its first 

 strength. ... Its tail stretched outward 

 just along the line of intersection of its 

 own with the terrestrial orbit to an extent 

 of fifteen million miles, so that our globe, 

 happening to pass at the time, found itself 

 during some hours involved in the flimsy 

 appendage. No perceptible effects were pro- 

 duced by the meeting; it was known to have 

 occurred by theory alone. A peculiar glare 

 in the sky, thought by some to have dis- 

 tinguished the evening of June 30, was, at 



best, inconspicuous. Nor were there any 

 symptoms of unusual electrical excitement. 

 CLEBKE History of Astronomy, pt. ii, ch. 

 10, p. 398. (Bl., 1893.) 



3380. TERROR, SUPERSTITIOUS 



Great Meteoric Storm of 1833. The most 

 notable modern one [shower of meteors] was 

 on November 13, 1833, and this was visible 

 over much of the North- American continent, 

 forming a spectacle of terrifying grandeur. 

 An eye-witness in South Carolina wrote: 



" I was suddenly awakened by the most 

 distressing cries that ever fell on my ears. 

 Shrieks of horror and cries for mercy I 

 could hear from most of the negroes of the 

 three plantations, amounting in all to about 

 six hundred or eight hundred. While ear- 

 nestly listening for the cause I heard a faint 

 voice near the door calling my name. I 

 arose, and, taking my sword, stood at the 

 door. At this moment I heard the same 

 voice still beseeching me to rise, and saying, 

 'O my God, the world is on fire!' I then 

 opened the door, and it is difficult to say 

 which excited me the most the awfulness 

 of the scene or the distressed cries of the 

 negroes. Upwards of one hundred lay pros- 

 trate on the ground some speechless and 

 some with the bitterest cries, but with their 

 hands raised, imploring God to save the 

 world and them. The scene was truly aw- 

 ful; for never did rain fall much thicker 

 than the meteors fell toward the earth ; 

 east, west, north, and south, it was the 

 same." LANGLEY New Astronomy, ch. 6, p. 

 194. (H. M. & Co., 1896.) 



3381. TEST OF SCIENTIFIC THE- 

 ORY Two Elements of Value. The value 

 which every scientific theory possesses is 

 measured by the number and importance of 

 the objects which can be explained by it, 

 as well as by the simplicity and universal- 

 ity of the causes which are employed in it 

 as grounds of explanation. On the one hand, 

 the greater the number and the more im- 

 portant the meaning of the phenomena ex- 

 plained by the theory, and the simpler, on 

 the other hand, and the more general the 

 causes which the theory assigns as ex- 

 planations, the greater is its scientific value, 

 the more safely we are guided by it, and 

 the more strongly are we bound to adopt it. 

 HAECKEL History of Creation, vol. i, ch. 

 2, p. 25. (K. P. & Co., 1899.) 



3382. TESTS, FUTILE, OF SPON- 

 TANEOUS GENERATION Death-point of 

 Bacteria Not Yet Found Supposed New 

 Life a Survival of the Old. I have had sev- 

 eral cases of survival [of germs] after four 

 and five hours' boiling, some survivals after 

 six, and one after eight hours' boiling. Thus 

 far has experiment actually reached; but 

 there is no valid warrant for fixing upon 

 even eight hours as the extreme limit of vi- 

 tal resistance. Probably more extended re- 

 searches (tho mine have been very extensive ) 

 would reveal germs more obstinate still. It 



