26 THE KIGHT HON. LORD KELVIN, G.C.V.O., ON 



ever be the shapes and sizes of the sohd granules when first 

 falling to the bottom, they must have lain in loose heaps 

 with a somewhat large proportion of space occupied by 

 liquid among them. But, at considerable distances down in 

 the heap, the weight of the superincumbent granules must 

 tend to crush corners and edges into fine powder. If the 

 snow shower had taken place in air we may feel pretty sure 

 (even with the slight knowledge which we have of the hard- 

 nesses of the crystals of felspar, mica and hornblende, and 

 of the solid granules of quartz) that, at a depth of 10 kilo- 

 metres, enough of matter from the corners and edges of the 

 granules of different kinds, would have been crushed into 

 powder of various degrees of fineness, to leave an exceed- 

 ingly small proportionate volume of air in the interstices 

 between the solid fragments. But in reality the effective 

 weight of each solid particle, buoyed as it was by hydrostatic 

 pressure of a liquid less dense than itself bynot more than 20 or 

 15 or 10 per cent., cannot have been more than from about ith 

 to xiyth of its weight in air, and therefore the same degree 

 of crushing effect as would have been experienced at 10 kilo- 

 metres witn air in the interstices, must have been experienced 

 only at depths of from 50 to 100 kilometres below the 

 bottom of the lava ocean. 



§ 29. A result of this tremendous crushiug together of the- 

 solid graniiles must have been to press out the liquid from 

 am.ong tliem, as water from a sponge, and cause it to pas^ 

 upwards through the less and less closely packed heaps of. 

 solid particles, and out into the lava ocean above the heap. 

 But, on account of the great resistance against the liquid 

 permeating upwards 30 or 40 kilometres through interstices 

 among the solid granules, this process must have gone on 

 somewhat slowly ; and, daring all the time of the shoaling of 

 the lava ocean, there may have been a cousiderable proportion 

 of the whole volume occupied by the mother liquor among 

 the solid granules, down to even as low as 50 or 100 kilo- 

 metres below the top of the heap, or bottom of the ocean, at 

 each instant. When consolidation reached the surface, the- 

 oozing upwards of the mother liquor nuist have been still 

 going on to some degree. Tlius, probably for a few years- 

 after the first consolidation at the surface, not probably for 

 as long as one hundred years, the settlement of the solid 

 structure by mere mechanical crushiug of the corners and 

 edges of solid granules, may have continued to cause the- 

 oozing upwards of mother liquor to the surface througk- 



