104 MARIOX EXPEDITIOX TO DAVIS STRAIT AXD BAFriX BAY 



eeedingly dangerous to a ship passing close by. The British steamer 

 Nessmore was severely damaged by such a projection, and it is com- 

 mon report that a similar obstruction caused the tragic loss of the 

 White Star Liner T'/tanie. 



The bergs which penetrate far south in summer, or dee])ly intc 

 the Gulf Stream, often assume a comi)letely Avater-washed. i)()!ishefl 

 form, like a beach-worn stone. (See fig. 74. p. 114.) No sharp i)rom 

 inences are visible anywhere and such bergs are usually low. hencf 

 very difficult to detect. The most striking form is given to iceberg.- 

 entering the North Atlantic by washing. The continual surging ol 

 the waves and swell back and forth finds the zone of greatest weak- 

 ness developing a central bore and later a deep, wide valley. Such 

 bergs are a familiar sight south of Xewfovmdland and are called b\ 

 various names : "" Valley." " dry-dock," '' winged.*' " bicuspid." " sad 

 die-back." and "' double-horned." (See fig. 68. ]>. 103.) 



Steamers often report two bergs close together when correctly 

 speaking, it is simply one old eroded iceberg whose valley bottom i^ 

 submerged beneath the sea. Blowholes and reentrant caves are noi 

 uncommon features through which the swell sometimes spouts 

 hundreds of feet in the au\ The valley berg, fragile in its las 

 stages, consists of thin walls, that eventually break off, and in period: 

 of smooth weather beautiful, curved, and slender "swan's necks" 

 are carved by the sea. High arches are on rare occasions sighted 

 In most instances they represent the washing of the waves tha 

 started with a small cave and wore it larger and larger, but in soim 

 cases they may be relics of caves formed in glacier fronts by tli- 

 escape of glacial thaw water. 



The icebergs are largest in the vicinity of the fjords soon afte 

 their birth and diminish in size the farther they are carried into th' 

 Atlantic. The highest berg of a group of 87 measured bv Drvaalsk 

 (1895, p. 401), in Northeast Bay was 447 feet. Hellaiid ( 187(), i 

 106). measured bergs to a height of iJl}2 feet and Steenstrup (188;^ 

 p. 90). 249 feet. Again Helland measured 8 bergs in the montl 

 of Jacobshavn fjord, 142, 14."). 146, 181, 198. 201, 343, and 3.56 feet 

 the largest of which contained 718,000,000 cubic feet (17.01)0,00 ■ 

 tons), with 230 feet as a common lieight for a large iceberg. Dry 

 galski measured a group of 70 bergs assorted as follows : Four wer 

 over 325 feet high, 14 were between 230 and 325 feet, 25 were betweei^ 

 160 and 230 feet, and 27 were less than 160 feet. The figures foi 

 bergs in the vicinitv of the large glaciers are as follows: 



Great Karajak : 250. 253. 207. 211. 250, 241 feet. Height of glacie 

 front, 160 to 330 feet. The average height of bergs from (h-ea 

 Karajak is 180 to 250 feet. 



Itividliarsuk: 194, 192, 214, 224, 230, 230, 95. 125 feet. Height o 

 glacier front, 227 to 260 feet. 



Jacol)shavn : 69, 105, 135. 214. 330, 336, 447 feet. Height of glacie 

 front, 277 feet. 



The f()re<:oing shows that Jacobshavn cahes the higliest ice 

 bergs in the north with (ii-eat Karajak following a ch)se second 

 The icebergs of east (jreenland are ap[)arently not so high as thos 

 of the west coast, as Amdrup (1900, p. 243), estinuites the largest o 

 these as 160 to 215 feet u\ height aiul about 3.280 feet in lengtli. Th' 

 loftiest berg observed by the international ice patrol south of Xew 



