112 Universiti/ of California Publications in Zoology [Vol. 15 



EXPLANATION OF TABLE 2, PART A 



The observations of temperature and the determinations of specific 

 gravity and salinity tabulated in this part were all made by \Vm. 

 T. Skilling, Professor of Physics and Physical Geography in the San 

 Diego Normal School, by means of a salinometer purchased from 

 Queen and Co., Philadelphia. The hydrometer was graduated to 

 0.001 and the specific gravity was estimated to 0.0001. As the instru- 

 ment was lost before being calibrated, and as the specific gravities 

 were found to be systematically lower by approximately 0.0008 than 

 those determined since 1908 relative to the same locations, they have 

 been increased by this amount. This may, therefore, be regarded as 

 a very crude calibration correction and, while the results are tabulated 

 to 0.0001, the average error is doubtless three or four times as great. 

 The results, in spite of the large error involved, clearly reveal the 

 difference in seasonal variation in salinity between the bay and the 

 ocean. 



First column. — Water sample numbers entered with respect first to location, 

 second to time. 



Second column. — Date. 



Third column. — Time when the sample was collected entered to the nearest 

 minute. 



Fourth column. — Temperature in situ. 



Fifth, sixth, and seventh columns. — Specific gravity of sample under atmo- 

 spheric pressure, the 1.0 being omitted; for meaning of symbols see page 48. 



Eighth column. — Salinity per mille determined with a salinometer as described 

 above. 



