damage, withdrawal of occupation forces, or inadequate maintenance 

 facilities. Suitable replacements or substitutions for these must be made, 

 and many new stations added to round out the initial stage of the 

 programme. If a reasonable degree of success is to be attained it will be 

 largely through co-operative effort. Various Government agencies, 

 scientific and engineering groups, and local- organizations and individuals 

 have already contributed invaluable assistance, and the future progress 

 of the programme must rely to a very large extent on their continuing 

 interest and aid. . . 



DESCRIPTION OF BATHYTHERMOGRAPH WITH WATER 

 SAMPLING APPARATUS 



, By A. F. Spilhaus, University of Minneapolis 



Summary of Discussion 



In reply to Dr. Frances Clarke's inquiry as to how deep the apparatus 

 could be used it was stated that the present model is built for 150 fathom 

 work, and the cost, which used to be inordinately high, is now brought 

 down to 700 dollars for the sea sampler and 400 dollars for the bathy- 

 thermograph. Dr. Clarke was advised to purchase an entire new 

 apparatus rather than to contemplate attaching the sea sampler to an 

 existing bathythermograph. 



Dr. Foerster wished to know if the bottles could be enlarged to provide 

 for increased volume samples. This could be done although displace- 

 ment increases error. The best way to enlarge the bottles would be to 

 lengthen them, though it would be much preferable to set two triggers 

 to operate at the same depth if a double sample were required. The 

 water sampler can actually be used in a stationary position, but it is 

 best worked at a moderately high speed, where a constant lag is attained. 

 If used in a stationary position it is as well to pull up slowly, and error 

 introduced can be easily corrected. 



Dr. Spilhaus pointed out in general the simplicity of his method, even 

 for use in fishing-boats, after which the titrating could be done ashore 

 and the whole data assembled by relatively untrained workers. 



It was asked whether provision could be incorporated for automatic 

 continuous recordings of salinity as the instrument went down. Work 

 was proceeding at Woods Hole along these lines, and perhaps ultimately 

 oxygen and salinity measuring instruments could be incorporated. 

 But the difficulties in letting down an electric cable are great. Dr. 

 Miller wondered whether, by using methods for eliminating the titrating 

 stages, oceanographers might not be providing themselves with a sort of 

 " Frankenstein " for providing data at much greater frequency than 

 could possibly be made use of. Mention was also -made of dropping 

 mercury electrodes to give continuous oxygen readings. But, of course, 

 the need for a sampler still remains. We have other needs in oceano- 

 graphical chemical data besides oxygen and salinity. 



Professor Burbidge assumed that most of the work described was at 

 low speeds ; it was pointed out in reply that 20 knots represents a con- 

 siderable speed for working. The instrument could not well be adapted 

 for greater depths than 150 fathoms, although a crude apparatus reached 

 1,000 fathoms, necessitating the use of water compressibility as the 

 pressure-gauging device. The accuracy, however, falls off markedly. 



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