190 University of California Publications. [Vol.6 



to be taken up in earnest until the summer of 1908, when the 

 writer was asked to become a regular non-resident member 

 of the staff of the Station, to be on duty at La Jolla for some 

 portion of each year, in charge of the water investigations. The 

 present report is the first of the hydrographic results to be 

 published, and will be understood to contain but a small portion 

 of all the data that have been collected, even during the last 

 two years. 



The plan adopted contemplates the employment, as soon as 

 possible, of the methods and instruments used by the Interna- 

 tional Council for the Exploration of the Sea. 



The work done during the summer of 1908 consisted of 

 temperature and density determinations of the ocean and bay 

 waters, and a series of soundings of the ocean; the area covered 

 lying between parallels 33° 20' and 32° 30' of north latitude, 

 extending from the coast to longitude 118° 30'. This area does 

 not include two trips to the Cortez Banks, which are situated 

 about fifty miles southwest of the eastern end of San Clemente 

 Island, and a trip south, below Cerros Island, to latitude 27° 40'. 



The temperature and density work was carried on as follows : 

 A pail full of surface water was dipped up, usually every twenty 

 minutes while the boat was moving along its course, and also 

 whenever catches were made; the temperature of the water was 

 immediately measured to the nearest tenth of a degree in terms 

 of the Centigrade scale. A pint of the water was then sealed 

 tightly in a glass fruit jar, so that a reference to the corre- 

 sponding number in the log book and on the map, showing the 

 ship's course, would give the temperature and position of the 

 sample, and the time when it was obtained. The average rate 

 of the boat being seven knots per hour, surface samples were 

 obtained at intervals of 2y s knots along the course. 



At a few stations water was taken from various depths by 

 means of the "Kofoid closing water-bucket." The temperatures 

 were taken and the samples preserved as before. The bucket, 

 which is open at the ends, is let down by means of a cable, wound 

 on a drum operated by the hoisting engine. When the desired 

 depth is reached the bucket is closed by means of a cast-iron 

 messenger, sent down the cable, and is immediately drawn up. 



