49 



OCEANOGRAPHY 



The oceanographic vessel of the ice patrol, the 125-foot patrol boat 

 General Greene, departed from Boston on April 2 on an ice-observation 

 cruise. Having arrived at the tail of the Grand Banks slie proceeded 

 northward, covering the area between the eastern edge of the Grand 

 Banks and Flemish Cap as far north as about latitude 47°30' N., and 

 thence in to St. Johns, Newfoundland, where she arrived on April 11. 

 On this cruise numerous sea-water surface temperature reports were 

 received from passing steamers, and these, together with continuous 

 thermograph records from the General Greene, formed the basis for the 

 chart of surface isotherms shown in figure 2. 



The inauguration of the ice patrol on April 17 relieved the General 

 Greene of her ice observation work and permitted her to function as 

 the oceanographic vessel. Therefore, on April 17 she sailed from 

 St. Johns for the purpose of constructing a dynamic topographic 

 chart of the Grand Banks area believed to be critical with respect to 

 the drift of menacing ice. The work of collection of data began on 

 April 19 at station 1599 southwest of the tail of the Banks and was 

 completed west of Flemish Cap on April 26 after 37 stations had been 

 occupied. The current chart, figure 17, was then constructed and 

 delivered aboard the cutter on patrol 32 hours after the last station 

 had been taken. The General Greene then proceeded to St. Johns, 

 arriving there on April 29. 



On May 16 the General Greene departed from St. Johns to make a 

 second current chart. As much ice had been reported in the area 

 between the Grand Banks and Flemish Cap, this area, as far north as 

 latitude 48 N., was included in the survey. The work of collection 

 began on May 17 at station 1636 and was completed near the tail of 

 the Banks on May 25 after 46 stations had been occupied. The 

 resulting current chart, figure 18, was delivered aboard the patrol 

 cutter 27 hours after the last station had been occupied. The 

 General Greene then stood northward along the eastern edge of the 

 Grand Banks as far as latitude 47 N., whence requisite courses were 

 steered for St. Johns, arriving on May 28. 



The General Greene sailed from St. Johns on June 11 to make a third 

 current map. The collection of data began on June 12 at station 

 1682. On the morning of June 15, at station 1697, it was discovered 

 that one group of strands of the wire rope had broken. The cable 

 was immediately cut and spliced at this point. The lower 350 

 meters of the cable then developed numerous small kinks which did 

 not seriously impair its strength for the purpose to which it is put but 

 which made the cable sufficiently irregular to prevent the passage of a 

 messenger. This length of cable was then cut off and thrown over- 

 board. Except for the cable there was no loss of equipment or 

 observations. On June 18, at station 1712, under current and wind 



