Fig. 31. Captain Ault about to descend in the diving hel- 

 met to untangle the sounding wires which had fouled 

 the oscillator in the keel during an oceanographic sta- 

 tion 



Fig. 32. The scientific personnel of the Carnegie on 

 leaving San Francisco in September 1929. Front row, 

 left to right: Parkinson, Captain Ault, Soule; back 

 row, left to right, Forbush, Seaton, Scott, Graham, 

 and Paul 



Fig. 33. Pendulum apparatus installed in the cabin for 

 measuring the force of gravity 



Fig. 34. The pendulums of the Vening Meinesz gravity 

 apparatus. Installed on the Carnegie at San Francis- 

 co to obtain measurements of the force of gravity in 

 different parts of the world, which are of great inter- 

 est to geophysicists in their study of the earth's crust. 

 These pendulums are made of "invar," an alloy which 

 does not contract or expand with changes in tempera- 

 ture 



28 



