y: Diving to i y oo fathoms 



TWENTY-FIFTH September 1953. Once more the Tenace proceeds 

 towards Castellammare. We are about to set out for the Trieste '^ 

 big test. In the yards, workers and engineers carry out the final 

 preparations. The Trieste^ motionless, is at the dock. Rejuvenated by a 

 coat of fresh paint, fitted with several new pieces of apparatus, it seems 

 to be waiting, just as impatient as ourselves, again to take up its 

 service on the high seas. 



What had we been doing since the dive off Capri } 



We made many small improvements : each dive is only a prelude to 

 the following dive and serves as a lesson for future experiments. 

 The towing speed was too low. We added a keel beneath the stern of 

 the float : perhaps it slightly decreased the remarkable stability of the 

 Trieste^ but not enough to be noticeable. We did this, not to prevent 

 rolling, but to increase the speed of the float on the surface. Actually 

 this keel permitted the towing speed to be trebled. 



A wire to a solenoid had been broken. This was put right, and a new 

 system was evolved to increase the efficiency of this component. 



We had been hindered by not knowing our vertical speed with 

 precision, so we built the tachometer which was described earlier. 



Light had been lacking towards the rear of the bathyscaphe, and to 

 remedy this a third projector was constructed identical with the first 

 and placed on the stern. 



A number of busybodies criticized what they thought was calcu- 

 lated delay, but in fact we did not waste a moment, and all the time was 

 spent providing the Trieste with improvements. It was not enough for 

 us to dive deeper: what we wanted was to develop the scientific 

 possibilities of the Trieste. 



Where were we to dive this time } 



We had marked out on the map, south of the Island of Ponza, 

 at some sixty miles to the north-west of Castellammare, a vast sandy 

 submarine plateau, whose depth varied between about 1650 and 1760 

 fathoms. It was an ideal spot for landing a submarine balloon. 

 However, it would mean a whole night's towing; but the sea was 

 calm, and we could set out without anxiety. 



At 4 p.m. we weighed anchor. Two sailors came aboard the Trieste^ 



["5] 



