How The World Will End

In a lectimt beforo the American Qeo graphiual Society Professor Fisku said : l'iuuüts aie continually integratirig diffusod material whicli tLey encouuter iu thuir progresa tluough space, aud it has buen tstimated that tho earth adds to itsult' nearly uue hundrcd ttiid fitty billion sueh icüteoric partidos every year. Secondly, it has buen proved that every planet must be slowly icsiug a part of ita iholur motion ot' rutu-tion. The effect of tidal Wavc9, whioh re fjaüssd oy the gravitatiou oí' Uquid tovvaid otüer plttüwtary uodies, is to ruturd ctilirqal motjon ; aud, in fact, tho terrebtiai d.iy ia lengtheaed by reason of the friotion of the tules, and is destmud iu tlie romote futaru tó. give aboüt tour liundrud and eignty houra oetween aüurisu and buuset. Tue eurth is also losmg molecular luotion by raaiation That 8OUJ0 terrestrial heat is lost without compensation - and very slowly, of eourse - eau hardly ba doubred, and lor the state ui' tliings thus ultiniuteiy to bs produced we may find a parallel in the present condition ol' the ruuoa. Tha" appears to aü'ord au examplo of the univorsal deatu whieh in au uauoncaivably diacaut future awnitö the entila solar system. If along witü the dissip ition of the molar áríd molecular inotioiis the plauuta are also lusing angular vulooity, thi loss of motiou wül ultiuiatüly resült m thu.r integration With the sun. Of two facts wüióii bear upun the subjoot, one (fainüiar to all studuuts of eience) is tha observed retardation of Kuuku's comut by thi íe8istauce of the medium through which it iriovw. Thy other, whioh, sO fur as 1 kuow, ha3 hot hithurto beun intiittioued, is that all the planeta' are rieuivr thu san than thuy ought to be, according to Bode's law, the variatión beiug most coiiópicuous, as ruight bo expectud in the case of Neptune. It is at least worthy of riotice that the diacrepancy is sm;h as mighc have been uuusad by a slow dimiuution of the anguLar velocitit'S of the planets. Anóther tact that the inturplaDetary spaces are ttlled with matter, and that eouscquently all planetary bodius rusbing through them must meet with resitanoe aud loae inouientum, proves tbat immense momentuqi wül be eaten up by thu resisting foroo. The loss of tangential inomuntuiu must bring all the plauuts Into the sun. As the planet slow ly draws near the suu its lost tangenttal iuoin-Tiitnn is feplaced and somewhat more than replaced by the added velocity due to thegravitative torce exertod by the sun at the shorter destance. At last the planet must strike the sun with tremendoüs force. The heat generatod by tho earth and the sun alone in such a collision vould sufflee to produce a temperature of nearly 5,0()Ö,U00.degrees centigrade. Of course diain legra tion would immediately follow, and the next stage is the dissipation of the whole into a nebuia.