2og DISCOVERY REPORTS 



echo soundings have been obtained, and on the evidence provided by all these soundings 

 it has been possible to arrive at some definite conclusions as to the bottom relief in most 

 of the above-named areas. 



The positions of all soundings obtained by the R.R.S. ' Discovery II ' were determined 

 by Lieut. A. L. Nelson, R.N.R., and the majority have been plotted by him on large-scale 

 charts. His careful and painstaking vi^ork has been of the greatest assistance in the 

 preparation of this report. Vice-Admiral H. P. Douglas, C.B., C.M.G., R.N. (retd.) 

 and Mr J. M. Wordie have been kind enough to examine this report in manuscript and 

 I am indebted to them for a number of valuable suggestions. 



SOUNDING MACHINES 



WIRE SOUNDINGS 

 For oceanic wire soundings the ships were fitted with the well-known Lucas sounding 

 machine,! manufactured by the Telegraph Construction and Maintenance Co., which 

 carries about 10,000 m. of 0-028 in. diameter single-strand bright steel piano wire in one 

 length. This wire had a breaking strain of 220 lb. The ordinary Baillie sounding rod, also 

 described in the Discovery Reports^ was used throughout for all soundings over 300 or 

 400 m., the weights being the usual cones and flats of about 22 lb. weight apiece. In 

 shallow water, and sometimes up to 500 m., the Admiralty 28 lb. sinker was used, as was 

 also a new pattern of bottom sampler designed by Mr F. E. C. Davies to bring up larger 

 quantities of material than were usually obtained by the ordinary methods. Certain 

 small defects which had been noted in the Lucas sounding machines fitted in the 

 'Discovery' and 'William Scoresby'^ were overcome in the later pattern fitted in the 

 ' Discovery II ', which gave every satisfaction on the occasions when its use was necessary. 

 Motor-driven Kelvin sounding machines were fitted in the ' Discovery' and ' Discovery 

 ir and a hand-operated one in the 'William Scoresby'. In the 'Discovery H' this 

 machine was seldom used except for the purpose of checking the accuracy of the shallow- 

 water echo-sounding machine. The positions of the Lucas and Kelvin sounding machines 

 in the ' Discovery ' and ' William Scoresby' have already been discussed in the Discovery 

 Reports. In the ' Discovery II ' the Lucas sounding machine was placed on the port 

 side of the forecastle head, about 12 ft. aft of the stem, and the Kelvin machine on the 

 starboard side of the bridge deck close to the chartroom door, the wire being carried 

 outboard by a boom and traveller. 



ECHO SOUNDINGS 

 The echo-sounding machines are of the British Admiralty pattern, and with the 

 exception of the experimental machine fitted in the ' Discovery ' for a year, were manu- 

 factured by Messrs Henry Hughes and Son of London. The mechanical details of the 



1 Kemp, Hardy and Mackintosh, Objects, Methods and Equipment, Discovery Reports, I, pp. 168, 169, 

 190 (1929). 



2 Kemp, Hardy and Mackintosh, loc. at. supra, pp. 210, 211. 



3 Id., p. 168. 



