vi PREFACE 



this handbook is primarily addressed : to those who 

 are willing to take observations, but fear that a lack 

 of scientific training will render their work or their 

 collections worthless. Anyone who follows the lines 

 here laid down may feel certain that his work will have 

 real value, that he is building a sound brick into the 

 pyramid of human knowledge. In order still further 

 to promote the work, the Challenger Society has named 

 an advisory committee of specialists in various branches 

 of oceanography, to whom may be referred through 

 the Honorary Secretary inquiries upon points which 

 are beyond the elementary scope of the handbook. 

 But all who propose to take observations, in whatever 

 branch, are strongly advised to spend a few days at 

 one of the marine stations (pp. 423-429), in order 

 thoroughly to understand the practical work. 



However valuable the information in this handbook 

 may prove to be, it must remain elementary. It is no 

 " royal road "; in no sense will it do away with the 

 serious study which all these must undergo who, not 

 content merely to record observations, wish also to 

 grasp the usefulness and meaning of what. they are 

 doing. But the book may fairly claim to have brought 

 between two covers instructions, of which many are 

 not in print, and the rest are scattered and hard to 

 find. 



The indiscriminate use by the writers of Fahrenheit 

 and Centigrade, metres and fathoms, will prepare the 

 reader for what he will find in the literature of the 

 subject ; an oceanographer must be able to think in 

 either scale. 



The selected list of manufacturers and tradesmen 

 (p. 438) should prove of value to the beginner. 



The object of the volume is severely practical — what 

 to do, and how to do it — written in language which, 



