and even from day to day as the currents and wind carry the bergs 

 through this region. 



The duties of the Patrol as laid down by the International Con- 

 ference on the Safety of Life at Sea, which convened at London, 

 England, on November 12, 1913, are to patrol the ice region during 

 the season of danger from icebergs and to attempt to keep the 

 trans-Atlantic lanes clear of derelicts during the rest of the year. 

 It was earl}'- realized that a scientific program, to increase the knowl- 

 edge of the causes of the annual ice phenomenon in this region (fig. 

 1 ) , would be necessary in order to intelligently conduct such a patrol 

 and make it a real contribution to the safety of life and property at 

 sea. This has been the purpose of the meteorological and oceano- 

 graphical observations since the very beginning. The duties of the 

 Ice Patrol vessel are then, (1) to ascertain the location and progres- 

 sive movement of the limiting lines of field ice and icebergs, to keep 

 in touch W'ith it as it moves southward, and to disseminate such in- 

 formation, for the guidance and warning of navigators in sufficient 

 time so that they may proceed with caution or pass well clear of the 

 danger area; (2) to make such scientific observations as will increase 

 the knowledge of why the limiting lines of the ice assume their ob- 

 served positions. Among the things it is sought to discover by the 

 scientific program are (a) some means of foretelling the drifts of 

 known icebergs, particularly during periods of fog, and (5) some 

 means of forecasting amounts of field ice and bergs from 3'ear to 

 year or at least the character of the next season — whether it will be 

 a heavy, normal, or light ice year. 



The Ice Patrol Force also stands ready to give assistance to vessels 

 in distress, to render medical advice by radio or actual medical care 

 wdienever possible, to give special ice information, and to destroy 

 derelicts and other floating dangers to navigation. It must be 

 strongly impressed, not only on the masters of merchant vessels, but 

 upon the officers of the Ice Patrol Force themselves, that these addi- 

 tional duties can be prosecuted only when they do not interfere with 

 the primary duty of the Patrol, i. e., the location of the ice-infested 

 area and the immediate dissemination of such information to every 

 one vitally concerned. 



It is readily seen that the performance of the duties outlined for 

 the Ice Patrol present a number of original problems. Paramount 

 among these is the double problem of, first, where in this vast Ice- 

 Patrol area should the search for ice be made and, second, having 

 once found the ice how to maintain contact with it and still to accu- 

 rately delineate the limits of the ice. No less important is the prob- 

 lem of tracking down and relocating icebergs after extended periods 

 of fog, for which the region is famous. Originally the first problem 



