Some very simple devices for various oceanographical uses 1 77 



should be able to give good service used from a moving ship, to reveal currents 

 differences between small and great depths. 



It remains only to remark that such simple congealing inclinometers with direction- 

 indicating powers as are being made, could be very usefully employed in non-captive 

 instruments sent down to the ocean depths to record the bottom water movements 

 there. The working principle would be that of the bathygraph of Ewing and Vine, 

 which achieves self-ascent under the lift of an oil-filled balloon after the detachment 

 of ballast left on the ocean floor. This is of course the principle of Professor 

 Picard's bathyscaphe but, as Ewing and Vine remark, " the problem of locating 

 the apparatus after it has reached the surface is a serious one ". 



ACKNOWLEDGEMENTS AND NOTE 



Thanks are expressed to Mr. A. J. Woods for his very valuable collaboration and 

 instrumental ingenuity; to Mr. D. Waugh for generous help when carrying out tests; 

 and to Doctors Bohnecke and Joseph for trials made aboard the German research 

 vessel Gauss. 



Though this is perhaps a strange finish to a paper such as the foregoing, the writer is obliged to 

 remark that the jelly bottles come specifically under the coverage of a patent which runs in most 

 countries having important fisheries. The patent in question relates to the Current Cone for which 

 the licence holders are Messrs Kelvin & Hughes. From them the final models of the slope-and- 

 direction indicators will presumably be procurable in due course. 



REFERENCES 



Carruthers, J. N. (1954 a). Some inter-relationships of oceanography and fisheries. Arch. f. Met., 



Geophvs. u. Bioklim.. B, 6 (12), 167-189. 

 Carruthers, J. N. (1954 b). On the instrumental measurement of line-shape under water. Deutsche 



Hvdrogr. Zeits., 7 (1/2), 1-14. 

 Scharfe, J. (1953), Gerate zur Messung an Schleppnetzen. Die Fischwirtschaft, Bremerhavn, (12). 



