OCEAN CURRENTS. 341 



said wonderfully with those of other authors, the task I 

 had undertaken was very gratifying as to the results. 



I must add tliat Belknap's temperatures were taken at the 

 end of October and the beginning of November, between 

 Trinidad Head and San Francisco, and end of December 

 between San Francisco and San Diego. The correction be- 

 tween the two cannot amount to more than one degree of 

 Fahrenheit. 



The temperatures on all my charts represent for this rea- 

 son the winter season, and to give the figures for the sum- 

 mer they must be increased by from five to eight degrees. 



The results of my investigation are made clear by Profiles 

 A-F and Charts II and III. They are as follows : 



(1.) The greatest difference in the temperature of the 

 surface water, between San Diego and Trinidad Head, is 

 noticeable nearest the shore. The following table will ex- 

 plain it. See Profiles A-F. 



Trinidad Head. San Diego. Difference. 



10 miles off shore 48.5° 59.8° 11.3" 



50 " " " 50.2 54.4 4.2 



100 " " " 54.0 59.9 5.9 



220 " " " 54.8 59.6 4.8 



(2.) The temperature ind^'eases at the line of Trinidad 

 Head gradually from 48.5^ 10 miles distant from shore, to 

 54.8° 220 miles distant from shore, indicating a difference 

 of 6.3^ between the two, while off San Diego the tempera- 

 ture remains about the same. 



(3.) The ten miles off shore surface temperature of 

 Trinidad Head finds its equivalent ten miles off San Diego 

 at a depth of 100 fathoms. Following the comparison — 

 that of 50 miles off Trinidad Head agrees with the one 200 

 fathoms deep 50 miles oft' shore, and 220 miles off shore the 

 Trinidad Head temperature is found 40 fathoms below the 

 surface on the San Diego line, 



(4.) Ten miles off shore the ocean has an average depth 

 of only one hundred fathoms, with the exception of three 

 submarine valleys — one between Trinidad Head and Point 



