THE BATHYSPHERE OF I934 249 



turn were attached to the vessel's cross beams. In addition, 

 each of the sheaves had an emergency stop of steel cable 

 in case the bolt gave way. 



Sheaves: The three sheaves through which the bathy- 

 sphere's cable passed are those used in our regular deep-sea 

 work. They are steel lumber sheaves, of 1 8 inches diameter, 

 and self-lubricating as each one carries an inner reservoir 

 of oil. They were capable of withstanding many times the 

 amount of strain to which they were subjected. 



Steam: Two vertical boilers supplied steam for the 

 winches. They usually functioned at about no pounds 

 pressure. 



Measuring Length of Cable: In 1930 the length of the 

 cable was measured in two ways, — by a meter wheel orig- 

 inally used in measuring cable length in our oceanographic 

 exploration, and by tying linen tapes to the cable as it 

 passed over a measured hundred feet. The first method 

 was soon given up as it was too difficult to constantly 

 change meters into feet, plus an additional recalibration 

 caused by the fact that the meter was intended for Yz inch 

 instead of % inch cable. The tapes were also discarded as 

 they were often cut as they passed through the steel sheaves 

 and lost. 



Eventually white oil paint was resorted to and is still 

 used. When the bathysphere is at the surface a paint mark 

 is made on the cable above a zero mark. As this progresses 

 down the deck it passes a series of figures at ten foot inter- 



