346 CALIFORNIA ACADEMY OF SCIENCES. 



examination of tlie ocean temperature off the coast of Lower 

 California, and regret to say that reports are wanting. 



We are not less ignorant of the ocean temperature next 

 to the coast of California within the sphere of the so-called 

 edd}^ current. Of course we have regular observations of 

 the ocean water next to San Francisco, and perhaps to San- 

 ta Cruz, Monterey., Santa Monica and San Diego. But they 

 will never determine the width and the character of the eddy 

 current, the existence of which and the northerly direction 

 of which is vouched for by Prof. G. Davidson in his "Coast 

 Pilot" (Manuscript, 4tli edition). 



Undoubtedly such a current exists, at least to some extent, 

 along our coast, for our coast vessels sailing northward 

 know how to profit by it in keeping close to the shore. We 

 have seen the muddy water of the Sacramento river driven 

 northward as a distinct stream for many miles. We have 

 heard of a part of a wreck, located near the Cliff House, 

 being found not many days after the accident near Eureka, 

 Cal. But still we are doubtful as to its existence, as to its 

 extent, and as to the persistence of its direction. 



As we are void of scientific proofs to corroborate any as- 

 sertions in regard to this matter, we have to recur to theory, 

 and fortunately meet with the very plausible one of K. 

 Zoeppritz on ocean currents. He shows by exact physical 

 analysis how superficial impulses will work on liquid masses, 

 and will be extended by the friction of the strata of the 

 liquid against each other downward. He elucidates by his 

 researches that the motion of the principal body of a liquid 

 mass, which is subject to a periodically changing surface 

 power, is determined by the average velocity of the surface, 

 and that the periodical changes penetrate only a thin surface 

 stratum. 



Thereby the winds are reinstated as powerful motors of 

 the ocean surface water. They communicate their average 

 direction to the lower masses of the water as well as to the 

 surface water, and Zoeppritz has calculated, for instance. 



