350 AGE OF THE EARTH AS AN ABODE FITTED FOR LIFE. 



above tlie lieap. But, on account of the great resistance agaiust tbe 

 liquid permeating upward 30 or 40 kilometers tlirough interstices 

 among the solid granules, this process must have gone on somewhat 

 slowly, and during all the time of the shoaling of the lava ocean there 

 may have been a considerable proportion of the whole volume occupied 

 by the mother liquor among the solid granules, down to even as low as 

 50 or 100 kilometers below the top of the heap or bottom of the ocean 

 at each instant. When consolidation reached the surface, the oozing 

 upward of the mother liquor must have been still going on to some 

 degree. Thus probably for a few years after the first consolidation at 

 the surface, not probably for as long as one hundred years, the settle- 

 ment of the solid structure by mere mechanical crushing of the cor- 

 ners and edges of solid granules may have continued to cause the oozing 

 upward of mother liquor to the surface through cracks in the first- 

 formed granite crust and through fresh cracks in basaltic crust subse- 

 quently formed above it. 



LEIBNITZ'S CONSISTENTIOR STATUS. 



80. When this oozing everywhere through fine cracks in the surface 

 ceases we have reached Leibnitz's consistentior status; beginning with 

 the surface cool and permanently solid and the temperature increasing 

 to 1,150° G. at 25 or 50 or 100 meters below the surface. 



PROBABLE ORIGIN OF CONTINENTS AND OCEAN DEPTHS OF THE 



EARTH, 



31. If the shoaling of the lava ocean up to the surface had taken 

 place everywhere at the same time the whole surface of the consistent 

 solid would be the dead level of the liquid lava all round, just before its 

 depth became zero. On this supposition there seems no possibility 

 that our present day continents could have risen to their present 

 heights and that the surface of the solid in its other parts could have 

 sunk down to their present ocean depths during the twenty or twenty- 

 five million years which may have passed since the consistentior status 

 began, or during any time, however long. Rejecting the extremely 

 improbable hypothesis that the continents were built up of meteoric 

 matter tossed from without upon the already solidified earth, we have 

 no other possible alternative than that they are due to heterogeueous- 

 ness in different parts of the liquid which constituted the earth before 

 its solidification. The hydrostatic equilibrium of the rotating liquid 

 involved only homogeneousness in respect to density over every level 

 surface (that is to say, surface perpendicular to the resultant of gravity 

 and centrifugal force); it required uo homogeneousness in respect to 

 chemical comi)osition. Considering the almost certain truth that the 

 earth was built up of meteorites falling together, we may follow in 

 imagination the whole process of shrinking from gaseous nebula to 

 liquid lava and metals, and solidification of liquid from central regions 



