Earth's Past and future Richard A. Procter. 



41 



Its cohering, and losses arc to take place that can never 

 be replaced. If you consider, iu looking back at the 

 former stages, you will find that each nowntugo used up, 

 as it were, the- materials that had boon provided 

 by r,lie former stage. Iu the gradual using up of car- 

 bonic acid wo find that th:! materials previously forming 

 the surface of the earth were gradually undergoing a 

 cUange. Then camo the time when vegetation used up 

 tne abundant supplies of carbonic acid gas. And theu 

 comes the time when animals are to uso up the vegeta- 

 ble supplies. Is It to l>e Relieved that tho process can 

 continue for an indefinite period 1 It seems to me that 

 tho way iu which man is consuming tho 

 vegetable supplies of the earth is such as to 

 show that there must bo au end. When man, the in- 

 ventor of so muuy machines which are using up tho 

 supplies of coal when man insists upon using the ma- 

 terials of the earth at such a rapid rate, we begin to see 

 our way toward tho end. By that means it seems to me 

 animal life will come to an end long before those mate- 

 rial physical processes by which astronomers see-that 

 the earth is passing toward its end. We see that the 

 earth ij parties with its internal heat; that the great 

 central sun. must, iu the long ran, draw do\vn to the 

 stage when he will no longer have that great supply of 

 beat which he now possesses. 



SOURCE AND CHARACTERISTICS OF ENERGT. 



There will be a loss of force, a loss of energy, using 

 these terms as they are beginning to bo applied by men 

 of science. Force is unchangeable. One foiin of force 

 changes into another. All energy working energy 

 maybe consumed; for instance, if you raise a great 

 mass of matter to a great hight, you have a certain 

 quantity of lorce available from the position of that 

 body, and iu tho falling down of that body 

 it may be m.ide to do work. Iu falling 

 down it gives out its heat and has no longer available 

 energy. It gives out energy according to the position of 

 the body before fell, but it is too much spread to be 

 useful. It becomes part of that heat that the earth will 

 eventually radiate into space. So with the sun's heat 

 whicli. being at a high degree, is a source of energy, but 

 finally, when it will have parted with that heat, there 

 will no longer be energy, although the force will be 

 spread throughout space and still be in existence. 



We find then the earth gradually tending toward the 

 end. Is the end apart from that which will result from 

 the consuming powers of man? Does it resemble the 

 end we recognize iu the case of the moon ? Wo see in the 

 moon an orb gradually dviug out. Is tne eatth tending 

 toward such au end as that 1 It seems to /ne that hero 

 we have introduced again the point to which I called 

 your atten lion. Here then again we have introduced 

 that question of tho prior condition of all the different 

 orbs of the solar system, the larger orbs existing with 

 much greater original heat and much 

 greater relative quantities of atmosphere, and there- 

 fore in a condition winch does not tend to reproduce 

 orbs in aoy stage, in any of the stages, that the smaller 

 orbs pass through. In this picture of the moon you see 

 quite enough of the aspect of$ it to say that the earth 

 will not pass to such a condition. The moon may be 

 looked upon truly enough as an orb that is dying 

 out nod no longer fit to subserve the purposes of 

 life. In the fullness of time it shall fall perhaps on the 

 central gun or earth, in some way to give out new sup- 

 plies of heat and energy; but at present it is iu a dead 

 state, and there is nothing in its appearance to show 

 that the earth will ever have this aspect. 



NO rnonAim.iTY OF THE KARTII BEING T.IKE TUB MOOW. 



Thi're i.s the moon with its surface covered over wita 

 these marks. IL-ro i.s a place [ooiuting to the picture 

 upon tho screen] where tho meteoric missiles have 

 fallen into the moon, corresponding in a certain sense 

 to tho stage when missiles of tho saina kind were falling 

 on the earth, but where. is tiie earth at that stage of ita 

 existence had ubundant materials out of which oceans 

 and atmospheres were to be formed, it would appoar as, 

 if the moon, by virtue of its smaller siza, had not; and 

 therefore all theso small signs of disturbance on tho 

 surface of the moon have been unchanged. There have 

 been none of theso processes, of which tho signs on the 

 face of the earth have not been swept away, or if 

 they exist at all exist far down below the strata 

 of earth which have been formed by denuda- 

 tion. Hero you have again that wonderful 

 scene of barrenness, and I conceive there is nothing in 

 what we know of tho earth to show it will ever arrivo 

 at this condition. Again I say that this earth 

 seems very unlikely indeed to present such an appear- 

 ance as that. I don't say, indeed, that the 

 atmosphere of tho earth can ne"ver fail to con- 

 tinue to clothe it. We have seen that parts of 

 the atmosphere have been withdrawn. It seems 

 conceivable that other parts of the atmosphere will 

 gradually be withdrawn by chemical processes, and 

 that then a time will come when the earth will no 

 longer have an atmosphere. Then there will be nothing 

 to cover the earth with those signs of volcanic action. 

 Therefore, I say the flual stage of the earth will be very 

 different from the final stage of the moon. 



Here is a larger picture showing the proportion of the 

 inoou'd surface and the kind of aspect which the earth 

 might nave presented in past ages if tho atmosphere had 

 been removed from it. There you see the signs of that 

 process of aggregation. It must have resulted from 

 having an ou-tside solid crust. Ifc would seem as if in 

 tiiat respect the moon might have resembled the earth. 

 Here is a picture showing a portion of the moon's sur- 

 face, wuica corresponds to what might have beea the 

 appearance of the earth in former ages. 



NO ATMOSPHERIC ACTION ON THE MOON. 



You see there is much to show us that at any rate no 

 two orbs of different sizes pasd through identically the 

 same stages. Here is the earth on which we live which 

 was passing through these stages when m a very differ- 

 ent condition from the present condition of the 

 moon. The moon now has no atmosphere, and 

 cannot have had any atmosphere of any apprecia- 

 ble extent. If it had, those markings on its 

 surface would have been swept away in great part, and 

 the moon would bo reduced to the condition of our 

 earth whou tho heat had passed away from it. But cur 

 earth will never have the appearance of the surface of 

 the moon, because those marks that might originally 

 have been seen havo been removed by the downfall of 

 hydro-chloric ami sulphuric acids in the first place, and 

 after that by the processes of denudation, rain showers, 

 snowfalls, and especially tho grinding action of glaciers. 



Now wo have traced the earth towards its flual condi- 

 tion. We look to the solar system, and find also a ten. 

 dency towards a final condition. Tho sun at least will 

 gradually part with its internal heat, and we may loot 

 forward to a long period during which the surface of the 

 sun will be fit for habitation, simplj r because it retains 

 and will retain enough of its former heat to be iu a hab- 

 itable condition. Thus can we look forward to see 

 more distant changes, to see the solar system, as it 

 were, traveling arouud suiue dktaut center, and see 



