313 



SCIENTIFIC SIDE-LIGHTS 



Hunting 

 :e 



ous theory [the nebular hypothesis] does 

 not account for some peculiarities which are 

 scarcely less remarkable than those on which 

 it has been based. In particular it does not 

 account for the strange disposition of the 

 masses of the solar system. Why should 

 the inner family consist of minor bodies, in 

 the main unattended, while the outer con- 

 sists of giant orbs with extensive families of 

 satellites ? Why should the innermost mem- 

 bers of the outer family of planets be the 

 largest, while just within there lies the 

 family of asteroids, not only individually 

 minute, but collectively less (as Le Verrier 

 has proved) than Mars or even Mercury? 

 Why should the two middle planets of the 

 inner family be the largest members of that 

 family? Laplace's theory gives no account 

 of these peculiarities, nor perhaps could it 

 be insisted that these peculiarities should be 

 explained; yet, if any other theory should 

 give an account of these features, explain- 

 ing also the features which we have seen 

 accounted for, then such theory would have 

 a decided advantage over Laplace's. It is 

 to be noticed also that Laplace's great nebu- 

 lous contracting mass is a very unsatisfac- 

 tory conception to begin with. No such 

 mass could rotate as a whole. And lastly, 

 Laplace's theory does not in any way corre- 

 spond with processes still taking place 

 within the solar system. It gives no ac- 

 count of the immense number of meteor- 

 flights and comets still existing within the 

 solar domain. PROCTOR Expanse of Heaven, 

 p. 182. (L. G. & Co., 1897.) 



1527. 



Opposed by Anal- 



ysis of Existing Nebula?. We have vast 

 gaseous masses intermingled with and sur- 

 rounding groups of stars, and apparently 

 spread with exceptional richness where 

 these stars or suns are most densely aggre- 

 gated. But this is not what we should ex- 

 pect to find if stars were formed out of this 

 gaseous matter. On the contrary, we should 

 expect that where stars were most numerous 

 there the nebulous matter would have been 

 most completely used up, so to speak ex- 

 hausted, as it were, in the work of star- 

 making. Nor, again, can we recognize in the 

 substances which appear to constitute the 

 gaseous nebulae the fitting materials for 

 making stars. So far as the spectroscopic 

 analysis of the gaseous nebulae extends, their 

 chief constituent would appear to be the 

 gas nitrogen, the element next in impor- 

 tance in their constitution being the gas 

 hydrogen, while a third element, as yet not 

 identified, seems to be present in their sub- 

 stance. I would not insist too much on this 

 evidence; but it must not be forgotten that 

 it is all the evidence we have; and it must 

 be regarded as at least an unsatisfactory 

 basis on which to rear the hypothetical de- 

 velopment of suns like our own, in whose 

 orb exist the glowing vapors of iron, copper, 

 and zinc, sodium, antimony, and mercury, 

 barium, carbon, silicon, and sulfur, and 



probably every single element known to our 

 chemists. PROCTOR Our Place among In- 

 finities, p. 229. (L. G. & Co., 1897.) 



1528. HYPOTHESIS VERIFIED BY 



EXPERIMENT The Undulalory Theory of 

 Light Conflicting Waves of Light Produce 

 Darkness. Every new hypothesis of scien- 

 tific value must not only furnish an exact 

 explanation of known facts, but must also 

 enable us to predict in kind and quantity 

 the phenomena which will be exhibited un- 

 der any given combination of circumstances. 

 Thus, in the case of the undulatory hypoth- 

 esis of light, it was inferred as a logical con- 

 sequence that if the supposition were true 

 that light consisted of waves of an ethereal 

 medium, then two rays of light, like two 

 waves of water under certain conditions, 

 should annihilate each other, and darkness 

 be produced. The experiment was tried, 

 and the anticipated result was obtained. It 

 is this exact agreement of the deduction 

 with the actual result of experience that 

 constitutes the verification of a hypothesis, 

 and which alone entitles it to the name of a 

 theory, and to a place in the transactions of 

 a scientific institution. It must be recol- 

 lected that it is much easier to speculate 

 than to investigate, and that very few of 

 all the hypotheses imagined are capable of 

 standing the test of scientific verification. 

 HENRY Organization of Smithsonian Insti- 

 lution, Scientific Writings, vol. i, p. 276. 

 (Sm. Inst., 1886.) 



1529. ICE A MILE AND A HALF IN 

 DEPTH Interior of Greenland an Unknown 

 Land. The interior of Greenland is re- 

 ported by the few bold explorers who have 

 crossed it to be completely buried beneath 

 a featureless plain of snow. This covering 

 has reached such a depth in all of the cen- 

 tral part that not a single mountain peak 

 is known to break the even monotony of 

 its surface. The snow is highest and prob- 

 ably deepest in the central area, and de- 

 scends toward the coast, thus giving the is- 

 land a convex surface. The general eleva- 

 tion of the central portion is from 7,000 to 

 8,000 feet, decreasing gradually toward the 

 coast, especially to the east and west, where 

 the glaciers, protruding like great tongues 

 of ice from the central region, come down 

 to the sea. The only mountain peaks that 

 rise above the surface of the general cover- 

 ing of snow are within from 50 to 75 miles 

 of the coast. These partially buried peaks 

 rise like islands in the sea of white. They 

 are known to the inhabitants of the coast 

 as nunataks, a convenient name that has 

 found a place in geological literature. 



The depth of the nearly universal cover- 

 ing of snow and ice under which Green- 

 land is buried cannot be told, as it is im- 

 possible to determine the topography of the 

 land beneath. The best estimates that can 

 be made place its depth at several thou- 

 sand feet. In the central portion, where 

 the covering is apparently thickest, its 



