168 MAEIOX EXPEDITION TO DAVIS STRAIT AND BAFFIX BAY 



and from the middle of July until the followin<r sprino; the area south 

 of the Grand Bank is practically free. An isolated berg or two may 

 drift southward to the Tail of the Bank, but not often south of the 

 latter, as late as October, after which month bergs are sighted rarely 

 in the latitude of the Grand Bank until the following February. 



It is interesting to note that of the fifty-odd icebergs which may be 

 expected to drift south of the Tail during a normal year, only three 

 will ordinarily be carried across the westbound steamship routes 

 which run between Eurojje and the United States. The bergs which 

 drift south of the lanes located along the latitude of 40° N. do so 

 in April, May, and June; May being the month which is most danger- 

 ous to shipping. The total number sighted along the tracks south 



VtOr 



JKA FER rm APR m m JOL ^U6 SiP ACT NOV PEC 



I*— ICE. SEASON—* 



The Normal Seasonal Distribution of icebergs 



FiGUUF, 100. — The uppei- curvo represents the normal 

 monthly number of icebergs south of Newfoundland in the 

 western North Atlantic. The lower curve represents the 

 normal number of bergs south of the Grand Bank. The 

 number of bergs are at a minimum during November, 

 December, and Januai-y, and at a maximum during April, 

 May, and June. The ice patrol has interpreted the normal 

 iceberg season as extending from the middle of March 

 to the middle of July. 



of the fortieth parallel during the decade 1918 to 1923 was 33, dis- 

 tributed as follows : 3 in April, 25 in May. 5 in June. 



Methods Employed to Pkotect Trans-Atlaxtic Shippixg from 



THE Ice Mexace 



Where the cold northern currents carry Arctic ice on to the Xorth 

 Atlantic lanes of commerce, there it becomes a distinct economic 

 menace to life and property. The protective measures taken every 

 spring against this danger are (a) a system of prescribed routes 

 south of the normal ice barrier, and (h) a ship patrol to warn ves- 

 sels of the position of the ice. 



The interesting accounts of the early Arctic explorations by the 

 British, the Dutch, and the Scandinavians relate to dangerous sit- 

 uations in which vessels Avere often surrounded and crushed within 

 the vast fields of ])ac'k ice. Thus in the year 1777 the Dutch Avhaling 

 fleet was unexpectedly caught in the heavy ice floes ofl' east (Green- 

 land and 12 vessels were swept away and sunk in the dangerous wa- 

 ters of Denmark Strait. The tragic loss of the famous Jeannette 

 and practically all of her crew was due to the great ])ressure of the 



Al 



