618 president's address. 



matter of no moment. The motion so begun would, under the 

 well understood action of gravity, be constantly accelerated, 

 until, with the lapse of time, material concentration had taken 

 place. 



As a result of this falling together, and ai)art altogether from 

 the enormous energy set free through the chemical reaction of 

 elements one with another, vast quantities of heat would be 

 generated. Lord Kelvin has calculated that the heat liberated 

 by the condensation of matter in this manner would be amply 

 sufficient to render the whole mass glowing hot, and would, in 

 the case of the solar system, readily account for the present 

 heated condition of the sun. The incandescent mass would surge 

 and boil out again, and probably in so doing become separated 

 into numerous portions, and these having in this manner 

 acquired initial proper motion, would form the nucleus of a solar 

 system. By slow degrees the vapours forming one of these 

 masses, which we will suppose to be the infant earth, would cool 

 down sufficiently to form a molten mass, in which only the more 

 intractable substances would be in a fixed condition, all the 

 others constituting a glowing atmosphere such as at the present 

 time surrounds the sun. Water would either be dissociated into 

 its elements or later on would exist as steam. As the process of 

 cooling went on the more readily condensed bodies would fall as 

 rain — iron, for example, as glowing drops of oxide — into a 

 molten sea surrounding the young world. Probably substances 

 like gold, platinum, silica, etc., having the highest melting points, 

 would be the first to condense, thus forming a heavy nucleus, 

 and it is possible that the rare heavy metals named, with many 

 others now obtainable only in small amounts scattered through 

 the upper crust of the earth, are but the froth and splashes from 

 immense central stores which formed the first core of the youth- 

 ful earth. It has been found that on an average the increase in 

 temperature of the earth's crust downwards for such depths as 

 we have been able to examine, is V F. for about 51 feet of 

 descent. The greatest depth, however, to which it has been 

 found possible to penetrate with the boring appliances at our 



