INTRODUCTION XIX 



to realize the falsity of the poetical description of the 

 " unplumbed . . . estranging sea." It is no longer 

 unplumbed, and as for estranging, well, I prefer an- 

 other poet's line : " the seas but join the nations they 

 divide." Also, the knowledge that so far from the 

 ocean below a certain depth being a place of absolute 

 darkness and death, it is everywhere the home of 

 living creatures adapted to conditions of life of which 

 we can form but the faintest conception, under almost 

 unimaginable pressure, in uniform cold, and in dark- 

 ness only faintly illumined by phosphorescent gleams, 

 emanating, not, as I read in a journal recently, from 

 decaying things, for there are no decaying things in 

 the sea, but from living illuminators glowing with 

 self-produced and self-sustained light a strange, 

 mysterious world, from which man is for ever shut out, 

 and about which his knowledge must necessarily be 

 fragmentary and incomplete. 



The terrible subject of naval warfare has been dealt 

 with in the same sketchy manner under the heading 

 of the ocean as a universal battle-field, a title which 

 I feel is sufficiently justified by the fact that, with but 

 few exceptions, all great powers that have anything in 

 them of stability have found it necessary to maintain 

 a navy. I have endeavoured to sketch the rise of 

 naval warfare from the earliest times, pointing out 

 how eagerly man, having discovered the utility of the 

 sea as an ever-level road, traversed far more easily and 

 with less danger than the land in those unquiet days, 

 grasped at the possibility of making it a place of war- 

 fare also, rapine and bloodshed being the normal con- 

 dition of his being ; how the necessity for defending his 

 merchandise, or the greed of the goods of others, also 



