MA.CKIE PHYSICAL A"N D C03MICAL PHENOMENA. 



1S1 



For this purpose, then, we commence in this article a series of 

 speculations on possible physical and cosmical phenomena in refer- 

 ence to the past conditions of our Earth, not always with the inten- 

 tion of proposing new views or even our own opinions, but as often 

 putting hypothetical cases to learn what would have been the results 

 produced by particular conditions of physical forces and the exertion 

 in particular directions of cosmical laws. 



At this lovely spring-time of the year, the bright warm beams of 

 the shining sun cause our eyes to rise to the blue and cloud-mottled 

 sky. All around, the green buds are shooting forth, and flowers blos- 

 soming and perfuming the balmy air. What would this beautiful 

 world be without that sunshine? What would indefatigable, active 

 man be without these cheering, life-exciting beams of the orb of day ? 

 The sun is but a great fire ; fire, we know, consumes the substances 

 it feeds upon ; gigantic as the solar orb may be, the fire must burn 

 it out, and, like the dark stars that astronomers now have indicated, 

 the time may come when the earth, changed, perhaps, it self to a burn- 

 ing mass, may reveal by its luminous beams to the astronomers of 

 di-tant worlds its revolutions round an unseen, dark, extinguished 

 sun. But without so deep a dive into the mysteries of time to come, 

 let us ask ourselves what would be the effect of minor alterations in 

 the solar fire ? AVe cannot believe the solar flames are always burn- 

 ing at exactly the same height, with exactly the same fierceness, 

 giving exactly the same heat, exactly the same light. The fire on 

 our hearth flickers, blazes, grows dull, requires fresh fuel, smoulders, 

 bursts into flame again, burns clear and ruddy, glows with radiant 

 heat, darkens, chinkles, and goes out. The consumption of the solar 

 fire must be supplied; we cannot believe that as particle by particle 

 is consumed, particle by particle is supplied. Even if meteors supply 

 the sun, they must vary in abundance at different periods of time. 

 If worlds fall in occasionally to supply the waste, the solar fires at 

 that spot must slacken, deaden, to glow out again bright and more 

 furiously when the new fuel is ignited through. For geological pur- 

 poses, without going into great variations of the solar fire, let us con- 

 ceive two modifications, — one of 15° increase of temperature from such 

 a cause, and one of 15° decrease. We are told the centre of the 

 earth is a burning incandescent fluid mass, — rather an uncomfortable 

 idea, and not quite intelligible. We are taught it, however, mainly 

 because the fossil relics of former creatures and plants are supposed 

 to indicate tropical conditions in latitudes whei e now temperate con- 

 ditions prevail. Unfortunately, however, in digging down into the 

 bowels of the earth we do not find the temperature increase more 

 and more with the depth, the heat increase faster ami faster as we 

 gel nearer and nearer to this imaginary central melting-pot; we do 

 not, in short, find the heat of the handle increase more rapidly as we 

 pass from the knob to the red-hot end of the poker. .Inst as (ilaisher 

 going up in the high regions of the air has disproved the old doc- 

 trine of a supposed decrease 1 of one degree of heal for every 300 feet 

 of vertical height, and found a gradually diminishing scale of loss, 1 



