A GLIMPSE THROUGH THE CORRIDORS OF TIME. 495 



set. This they will find a most suitable and agreeable arrangement. 

 They will look back on our short periods of rest and short periods of 

 work with mingled curiosity and pity. Perhaps they will even have 

 exhibitions of eccentric individuals able to sleep for eight hours, work 

 for eight hours, and play for eight hours. They will look on such 

 curiosities in the same way as we look on the man who undertakes to 

 walk a thousand miles in a thousand hours. 



I am beyond all things anxious to give you the impression that I 

 am not indulging in any mere romance. No doubt the various figures 

 I have mentioned are but estimates. They may be found to require 

 correction perhaps large correction ; but the general outline of the 

 theory must be true. Should any traces of doubt still linger in the 

 mind .of some prejudiced person, let me finally dissipate them. Per- 

 haps some caviler may say : " Where are the proofs of all this action of 

 the tides ? How do you know that the tides are sufficiently powerful 

 to produce such changes ? " I believe I have shown this abundantly, 

 but some people require a great deal of conviction. I have therefore 

 kept my best argument for the end. 



For an overwhelming proof of tidal efficiency I shall summon the 

 heavens themselves to witness, and I shall point to the stupendous 

 task which tides have already accomplished. As the moon has made 

 and is making tides on the earth, so the earth once raised tides on the 

 moon. These tides have ceased for ages ; their work is done ; but 

 they have raised a monument in the moon to testify to the tidal suffer- 

 ings which the moon has undergone. To that monument I now con- 

 fidently appeal. The moon being much smaller than the earth, the 

 tides on the moon produced by the earth must have been many times 

 as great as the tides on our earth produced by the moon. It matters 

 not that the moon now contains no liquid ocean. Nor does it matter 

 whether the moon ever had a liquid ocean. In very ancient days the 

 moon was not the hard, rigid mass which it now appears. Time was 

 when the volcanoes raged on the moon with a fury which nothing on 

 our earth at present can parallel. The moon was then in a soft or a 

 more or less fluid condition, and in this viscous mass the earth pro- 

 duced great tides. 



Great tides in truth they were, for the earth is eighty times as 

 heavv as the moon. On the other hand, the moon is only one fourth 

 the diameter of the earth ; so that the actual height of the tides on 

 the moon would be still many times as great as the tides on the 

 earth. When the moon was nearer to us, as it was in early ages, 

 those tides were still greater. Think for one moment of what a 

 lunar tidal wave of such magnitude would be capable ! This wave is 

 perhaps of molten lava ; it would tear over the surface with terrific 

 power, and anything that friction could accomplish that great current 

 would do. That tidal current has done its work ; even if the moon 

 were fluid at the present day, it could no longer be distracted by tides. 



