290 THE LAST CRUISE OF THE CARNEGIE 



a new Kolhorster penetrating-radiation apparatus in Pasadena 

 and with Parkinson subjected it to further trials under the waters 

 of Crystal Lake near San Francisco. This instrument registers 

 the quantity of penetrating-rays reaching the earth and may be 

 lowered into the sea to determine the depth at which this powerful 

 form of energy is absorbed. Mr. Gish also supervised the in- 

 stallation of a photographic conductivity-recorder which had 

 just been designed and constructed in our shop in Washington. 



Forbush had brought with him several new chronometers and 

 a photographic time-signal recorder with which time-comparisons 

 could be made accurately to one-tenth of a second and approxi- 

 mately to one-hundredth. These delicate time-checks were 

 necessary for the "gravity-apparatus." He also brought new 

 silk plankton-nets for capturing organisms floating in the sea. 



Graham had just come from the Scripps Institution in La Jolla 

 where he had spent a month in studying the methods used in 

 chemical oceanography. He and Dr. Moberg spent most of their 

 time in San Francisco in reconditioning the oceanographic labora- 

 tory and in preparing new standard solutions. It was impossi- 

 ble to use the delicate chemical balance on board so these men set 

 up the instrument on the pier. Graham also found time to cali- 

 brate the bottles which were to be used in determining the amount 

 of oxygen in sea-water. We had had such difficulty in obtaining 

 distilled water of sufficient purity for our chemical work that it 

 was decided to buy a small still of our own. Before Graham could 

 take it on board he had to sign five copies of an affidavit that it 

 would not be used for making liquor. 



The gravity-apparatus which was installed in the cabin by Dr. 

 Wright was now to be tried out for the first time on a surface- 

 vessel. Cruises in Dutch and American submarines had shown 

 that it might be expected to give reliable measurements if the 

 roll of the ship did not exceed 10°. Besides this we were not 

 bothered with constant vibration due to engines. The pendulum- 

 equipment was designed by Dr. Vening Meinesz of Holland and 

 was perhaps the most delicate instrument on board. It recorded 

 photographically the swings of three pendulums and recorded on 

 the same paper the beats of a chronometer whose rate was known 



