viii PREFACE. 



It was originally intended that the general account 

 should have been a joint production, each of us con- 

 tributing his part. There were difficulties, however, 

 in the way of this arrangement. We were all fully 

 occupied with other matters, and the amount of 

 communication and correspondence between us, re- 

 quired to carry out the plan of joint authorship, 

 seemed likely to prove a cumbrous complication. 



It was therefore decided that quoad the popular 

 exposition I should take upon myself the office of 

 1 reporter,' and thus it comes about that I am indi- 

 vidually and solely responsible for the ojrinions and 

 statements contained in this book, save where they 

 are included within quotation marks, or their sources 

 otherwise acknowledged. 



Since we began these deep-sea investigations, 

 inquiries have come in from all quarters, both at 

 home and abroad, as to the implements and methods 

 which we employ. To supply the desired informa- 

 tion, I have described, in detail, the processes both 

 of sounding and dredging; and I hope that the 

 special chapters on these matters — the result of 

 considerable experience — may be found useful to 

 beginners. 



I pretend to no special knowledge of physics, and 

 I should have greatly preferred confining myself to 

 the domain of Biology, my own proper province ; 

 but certain physical questions raised during our late 

 explorations have so great importance in relation to 



