THE TIDES 157 



filled with the debris of ships, the shore is a welter of 

 boiling foam, and the people, gazing spell-bound with 

 terror, breathe again as knowing the worst. Contrary 

 to the usual rule of waves, the first of these rollers is 

 generally the most severe. It is followed by three or 

 four others, much diminished ; but the damage is done 

 by the pioneer. Then the sea resumes its normal 

 aspect, and the observers are left wondering why this 

 great visitation has come and what is the cause of it, 

 while seamen call it a tidal wave. 



Well, since nothing is known of the origin of 

 these manifestations perhaps one name is as good as 

 another only, if the tidal wave which rolls round the 

 world twice in every twenty-four hours were always to 

 manifest itself in such a fashion, it is safe to say that 

 very little shipping business would be carried on. No, 

 the work, the beneficent work, done by the moon, and 

 in lesser degree by the sun, in raising the waters of 

 the ocean, is managed in a much gentler fashion than 

 that. Except under abnormal conditions, such as have 

 already been outlined, the tides rise and fall. Just 

 that. The words express exactly the gentle and 

 unobtrusive way in which these great forces of Nature 

 act for the comfort and convenience of mankind. But 

 the terrible manifestation of the " rollers " has been 

 observed and recorded in its most awful aspect during 

 an earthquake or a volcanic eruption occurring near the 

 shore. Then, as if to form the culmination of the 

 terror on land and in the air, the sea first appears to 

 recede, to rush seaward, until the secrets of the depths 

 are revealed, and scenes never before exposed to the 

 light of day become visible. Great ships are left 

 stranded where a little while before they floated in 



