116 



water surfaces were not smooth, but dimpled. This condition was 

 undoubtedly due to differential melting about the individual glacier 

 grains. This dimpled effect is almost always noticeable when the 

 water lines of bergs are closely inspected. Perhaps the underwater 

 bodies of bergs while melting about the Grand Banks, though smoothed 

 and rounded in general outline, may all be composed W'hen the detail 

 is considered of these roughened surfaces. They can be compared to 

 nothing so well as to magnified "goose-flesh" w^ith the intervals 

 between the individual projections or the individual hollow^s of the 

 order of about half an inch. 



To mention a few^ more examples of berg disintegration observed 

 during the 1929 season it can be stated that on the afternoon of July 24 

 the ice patrol was standing by a berg in 61° water 55 miles south- 

 southeast of the Tail. The berg was seen to calve heavily. In a 

 few minutes a boat put out from the patrol ship with a swimming party 

 and a number of the growlers in the vicinity of the berg were boarded. 



This could be easily be done, either from the boat or the w^ater, 

 without much discomfort, for the chilling eft'ects of the ice on the 

 surface water could be noted on ordinary ship's hold water ther- 

 mometers only when within a few yards from some of the berg's ice 

 walls, and when the boat was in the midst of a group of growders 

 spaced on the average 50 feet or less apart. In a few such places tem- 

 peratures 58° F., but 3° low^er than the general sea surface of the 

 neighborhood, w^ere recorded. 



About the berg that pitched wdien calving on July 15 slightly 

 greater local depression of surface temperature was noted. This berg, 

 as already stated, w^as surrounded by sea water of 57° F. temperature 

 at the surface. In one direction only from this berg w^as any chilling 

 noted, but a depression of over 1° F. extended on this side to about 

 one-fourth mile from the ice. Close to the berg the sea was 54° to 

 52° F. at the surface on this chilled side, and here, inside an ice- 

 bottomed, w^ell-washed bay cut into the berg behind an outljdng ice 

 pinnacle the temperature was 50° F. Among some near-by growlers 

 a minimum surface temperature of only 48° F. was found. On the 

 other hand, unchilled 57° F. surface water was found close to the 

 vertical walls of the berg on the side opposite to the chilled water and 

 growlers. The w'eather w-as calm, warm, and clear, and there was 

 onl}^ a slight swell. 



5. POSSIBILITY OF BREAKING UP ICEBERGS ARTIFICIALLY 



It has often been stated that noise or small blows can break up 

 bergs. The firing of 6-pounder blanks and the sounding of the steam 

 whistle and siren within 100 yards of unstable looking bergs has always 

 failed to bring dow^n any pieces of ice at all during the dozen or more 

 instances-^ in w^hich the writer has seen it persistently tried. Even 



