268 POPULAR LECTURES AND ADDRESSES. 



lowest to highest would be to be observed, with 

 gradually diminishing amount from century to 

 century, as through the dissipation of energy 

 produced by this tide the instantaneous axis of 

 the earth is gradually brought into coincidence 

 with the fresh axis of maximum moment of 

 inertia. If we multiply these figures by 3600, we 

 find what would be the result of a similar sudden 

 upheaval and subsidence of the earth to the 

 extent of 360 metres above and below previous 

 levels. It is not impossible that in the very early 

 ages of geological history such an action as this, 

 and the consequent 4OC-metrcs tide producing a 

 succession of deluges every 306 days for many 

 years, may have taken place ; but it seems more 

 probable that even in the most ancient times of 

 :.;<:< 'logical history the great world-wide chan; 

 such as the upheavals of the continents and 

 subsidences of the ocean-beds from the general 

 level of their supposed molten origin, took place 

 lually through the thermodynamic melting of 

 -solids and the squee/.ing out of liquid lava from the 

 interior, to which I have already referred. A slow 



