CURRENT AND DRIFT OF THE SHIP 133 



The drift in a direction parallel to the coast was found on the whole to be weak. 

 It was greater inshore where it had a mean velocity of 10-12 miles a day, than at a dis- 

 tance of 100-130 miles where the mean velocity in a direction parallel to the coast was 



MILES FROM COAST 

 ISO 100 



[CHILE-PICHIOANQUE &AV ONLf l CHILE 



I 5 bl 4 I 6 -7 B 



NORTH PEFUJ 



CHILE AND PERU 



Fig. 14. Diagram illustrating the ratio of northerly to 

 southerly drift (respectively above and below base-line) 

 at different distances from the coast. The data are plotted 

 separately for Peru (uppermost) and for Chile (centre) ; 

 and in combination for the west coast as a whole (lower- 

 most). The drift, expressed as miles per day, represents 

 the mean drift of the ship in a direction parallel to the 

 coast; and is computed by dividing separately the total 

 amounts of the drift in each direction by the total number 

 of observations in both directions. 



^ 





l-iol 

 L30 



ICHI LCRCHIDANOUE BAYONLYI CHILE ~\ 



I a ^ I3I 4 I 6-7 \4 



NORTH PERU [ PERU 



CHILE AND PERU 



[ IQ-15 



5S 



ma 



15 S 



Fig. 15. Diagram illustrating the mean residual drift 

 at different distances from the coast. The drift of the 

 ship in a direction parallel to the coast is expressed as 

 miles per day and is computed by dividing the difference 

 between total drift towards the north and towards the 

 south, by the total number of observations. The data are 

 plotted separately for Peru (uppermost) and for Chile 

 (centre) ; and in combination for the west coast as a whole 

 (lowermost). 



only 3^ miles a day. There was no sudden change from the zone of heavier drift to 

 that of lesser drift, but the mean values over the whole coast showed a slow reduction 

 with increasing distance from shore. Observations on drift at distances beyond 130 

 miles were made on only four lines, and these being off Peru are insufficient to allow 

 of generalizations. 



4-a 



