20 



Straits of Belle Isle. The course was laid along the probable axis of 

 the cold stream, as shown from past surveys, just inside the 600- 

 fathom curve and the ship's course changed as necessary to remain in 

 cold water. In this manner the vessel remained in water whose tem- 

 perature was constantly 1° below freezing, 31° F. By this method the 

 Pontchartrain searched an area of southward moving water 48 mUes 

 wide between latitudes 49° N., and 52° N., a region known, in any 

 normal year, to contain many icebergs and through wliich any bergs 

 bound for the critical area south of latitude 44° N., must pass. Only 

 one iceberg and two growlers were found in this area. 



On April 30 and May 1 the search was continued to the southward 

 south of latitude 49° N., along the northeastern slope of the Grand 

 Banks outside the line scouted out earlier in the cruise. No new ice 

 was sighted in this area but in the evening of May 1 a berg first 

 reported in latitude 46°01' N., longitude 47°25' W., was relocated in 

 latitude 45°38' N., longitude 47°38' W., showing a drift of only 25 

 miles in 3 days. The Pontchartrain drifted in vicinity of this berg, the 

 southernmost ice, during the night. Dense fog, general over the Grand 

 Banks, on the morning of May 2 prevented the relocation of this berg 

 so at 0945 the Pontchartrain set course for the relieving point making 

 such speed as the visibility would permit. (See fig. 21.) 



The Champlain was met in latitude 43°13'30" N., longitude 57°29' 

 30" W., at 1642, May 4, 1936. A boat was lowered and Lt. G. 

 Van A. Graves, ice-observation officer, and the observer's party were 

 transferred to the Champlain, and at 1850, the Champlain relieved the 

 Pontchartrain as observation vessel. The Pontchartrain set course for 

 Halifax, Nova Scotia, arriving there at 0836, May 6, 1936. 



The following is a summary of ice and water-temperature reports 

 received during the patrol: 



Number of bergs reported south of latitude 48° N 7 



Number of bergs reported south of latitude 43° N 



Number of vessels furnishing ice reports 18 



Number of ice reports received 18 



Number of vessels furnishing water-temperature reports 92 



Number of water temperature reports received 998 



Number of vessels furnished special information 9 



FOURTH CRUISE "CHAMPLAIN," MAY 5 TO 18, 1936 



The Champlain sailed from Hahfax, Nova Scotia, at 0555, May 3, 

 1936, on ice-observation duty. Moderate southerly winds, slight sea 

 and dense fog were experienced en route. The trip was uneventful, 

 and at 1640, May 4, the Champlain met the Pontchartrain in latitude 

 43°12' N., longitude 57°26' W., Lt. G. Van A. Graves, ice-observation 

 ofl&cer, and the observer's party reported aboard and at 1850 the 

 Champlain relieved the Pontchartrain as ice-observation vessel. 



