366 



MISCELLANEOUS STUDIES 



Direct estimates of the drift were made at six stations along this 

 line from angular measurements relative to a float, the ship being 

 manoeuvered in such a way as to keep the sounding cable as nearly 

 vertical as possible. The values obtained at each station in the order 

 from north to south are 1.0, 0.7, 0.9, 0.8, 0.9, 1.3 miles per hour in a 

 southwesterly direction. Each value is the mean of about twenty-five 



Fig. 3. Geometrical construction for determining the effect of a coast on 

 the surface current produced by wind. 



observations. The components parallel to a line from the first to the 

 last station having the mean direction of the observed drift are 0.99, 

 0.7, 0.9, 0.7, 0.86, and 1.11 miles per hour, and the mean value is 0.88. 



From the four estimates based on "dead reckoning" and the 

 position of the ship determined from astronomical observations at 

 noon, the drift appeared to be directed to the west of the direction 

 determined by the "float" method. The values are 0.4, 0.5, 0.4, 0.4 

 and the components parallel to the mean direction of the drift found 

 by the float method are 0.3, 0.2, 0.16, 0.19, the mean value is 0.21. 



The wind blew steadily from the northeast, the observed velocities 

 in miles per hour being 28, 23, 28, 34, 3, 18, 13, 28, 28, 28, 34, and 34 ; 

 the mean is 25. 



From equation (78), page 363, using 24, the mean latitude of the 

 stream line for <f>, the drift due to a wind velocity of V miles per hour 

 would be .01975F miles per hour. Using the value 25 for V the un- 



