.'■IS 



formed caused stable equilibfium and prevented capsizing. Such a 

 berg reduced its size uniformly while maintaining an UDright position, 

 forming new water lines, one below the other as the berg lost bulk, 

 until the last stage of disintegration was reached when the mass broke 

 up into dangerous gi-owlers. The "dry dock" was probably due to 

 the action of the sea on cracks or crevices in the berg. 



Bergs which did not form the "dry dock" at the beginning of their 

 dissolution, usually disintegrated irregularly, losing theu' equilibrium 

 and capsizing, thereuron throwing off considerable ice and continuing 

 this action until completely gone or until a small "dry dock" type 

 was formed. In capsizing usually dangerous growlers were formed 

 and considerable detritis drifted away. Bergs that capsized showed 

 evidence of undenvater currents producing melting. 



Many bergs had tongues projecting from under the water. It was 

 found that the tongue was caused by the underwater melting and 

 the slopping of the warm water waves against the ice. This tongue 

 was usually found in the "dry dock" ty]^e of berg. It was this tyj e 

 of underwater ice that the Saugus grounded on. 



At best most bergs appeared to be in an unstable equilibrium so 

 that the slightest irregular melting caused a shifting of the center of 

 gravity, thus causing the berg to take a new position and in some 

 cases completely turn over. In one case the Modoc observed a large 

 berg oscillate in which the period was eight minutes. 



The greatest amount of destruction done to a berg was by heavy 

 seas. The greatest amount of disintegration, due to expansion and 

 contraction, was observed to take place at noon and shortly after 

 smiset. 



Considerable air seemed to be contained in the berg. This was 

 probably resj^onsible for the opaque appearance of these bergs. 

 Whenever small jueces of ice fell into the water they seemed to effer- 

 vesce like soda water, due probably to the liberation of the air noted 

 above. 



Although the ice appeared soft it was exceedingly hard, especially 

 the ice which had not been subject to the disintegrating processes. 

 Ice Avhich had been underwater was brittle neai' the surface. Mining 

 and gun fire dislodged very little ice when concentrated on a compara- 

 tively new berg. A berg in the last stages of disintegration was 

 usually rotten and easily shattered. Disintegration seemed very 

 slow below 36° F. Between 36° and 50° F., the melting and erosion 

 were more noticeable, es] ecially in the formation of new waterlines. 

 When the bergs reached the warmer water, esjiecially 50° and above, 

 they seemed to disintegrate rapidly. There was a constant crackling 

 sound and often very loud reports were heard. 



Innumerable attem])ts were made to dislodge ice by the blowing 

 of the whistle and by concussion, but without success. In a great 

 many cases wlien the whistle was blown no eclio was heard. The 



