179 



It is believed that the drift cards reflected with a 

 reasonable degree of accuracy the direction and velocity of 

 the upper foot or two of water » To some unknown extent they 

 are directly influenced by the wind,, While the magnitude of 

 this error is not known, it seems reasonable to assume that 

 over short periods of time, during the 1 to 3 days required 

 for many of the cards to reach the beach, and during the 

 periods of relatively low wind velocities which were present 

 following most cruises, they were not deflected enough to 

 invalidate the general conclusions which have been drawn from 

 their drift „ 



One annoying occurrence was that obvious errors in date 

 of recovery were made by those returning the cards. Perhaps 

 this was to be expected, especially since many of the returns 

 were made by children. Such errors were difficult to elimi- 

 nate, because at some stations returns were spread out over 

 many days and there was no valid basis on which to decide 

 whether or not any early find was actually made on the date 

 recorded. Consequently, all cards were accepted at their 

 face value except a few which gave quite impossible velocities, 

 even negative ones. It is for this reason that the highest 

 velocities described for each cruise may sometimes be open to 

 question. In general? however, high velocities at any one 

 station were supported by more than one card or by similar 

 velocities from adjacent stations and the general picture, 

 therefore, is unchanged. 



The drift card cruises were scheduled at more or less 

 regular intervals, and because of the nature of the whole 



