130 DISCOVERY REPORTS 



as previously arranged. Dr Clarke's judgement in making additional observations during the second 

 survey, when more time unexpectedly became available, greatly increased its value. Owing to his 

 preoccupation with whaling research he has not participated directly in the writing of this report. 

 In preparing the account of the second survey we have frequently made use of his journal. That the 

 field work owed much to his efforts throughout should be obvious. All chemical estimations made at 

 sea were carried out by Mr Currie. 



We are particularly indebted to the Director of the Marine Biological Association's Plymouth 

 Laboratory and his staff for unrivalled working facilities before the new premises of the National 

 Institute were available, for much fruitful discussion and for practical help. By arrangement with 

 Dr G. A. Steven, Skipper W. H. Crease with his crew of the R.V. ' Sula ', and the M.B. ' Gammarus ', 

 gave much help while the ship was in Plymouth on her outward voyage, and again on her return. 



All our colleagues on the staff of the National Institute have assisted the work in some measure, 

 but special thanks are due to Dr G. E. R. Deacon and Dr N. A. Mackintosh for their valuable advice 

 and encouragement during the preparation of this report, to Dr H. F. P. Herdman for the care and 

 attention he devoted to the scientific equipment of the ship before sailing, and to Miss D. M. E. 

 Wilson for assistance in computing of values and checking data for the station list. 



The assistance of the naval authorities who ' mothered ' the ship when she called at Devonport, 

 Gibraltar, Freetown and Simonstown, extended down to the provision of odd spares for what must 

 have seemed to them some very odd gear, and was, of course, absolutely essential to the successful 

 completion of this part of the programme. 



We also wish to record our thanks to the Director of the Naval Weather Bureau for providing 

 relevant meteorological data; to Cmdr C. E. N. Frankcom, O.B.E., R.N.R., of the Marine Division, 

 Meteorological Office, and to Mr E. W. Barlow of his staff for data on surface drift and much helpful 

 discussion. 



Dr J. H. Oliver assisted greatly in devising a suitably robust instrument for carrying out our 

 phosphate determinations and by providing laboratory facilities in London before the ship sailed. 

 Dr K. R. Butlin, of D.S.I.R., assisted by confirming the presence of sulphate-reducing bacteria in 

 the bottom-sample from St. WS 1074. 



Many people in the Union of South Africa befriended the ship, both officially and personally. 

 Among those who helped more particularly with our Benguela current problems were: Dr C. von 

 Bonde, then Director of the Fisheries Survey Division, Department of Commerce and Industries, 

 and his staff, who gave us laboratory facilities and opportunities for discussion on many topics of 

 common interest. The Head of the South African Weather Bureau provided most valuable data. 

 Commander W. J. Copenhagen, with whom we have discussed plankton production and the 'Walvis 

 Bay problem ' over many years, introduced us to Dr Liebrandt, Director of Chemical Services, Depart- 

 ment of Agriculture, who provided chemical laboratory facilities on this occasion. Dr S. P. Jackson 

 of the Geography Department, University of Witwatersrand, gave most valuable advice on the 

 meteorological factors involved, as did Professor J. H. Day of Cape Town University on zoological 

 matters. Dr J. H. Maconnell of Walvis Bay, supplied some first-hand local information on the fish 

 mortalities. 



PREVIOUS WORK 



Early voyages 

 West African exploration received its greatest initial impetus in the latter half of the fifteenth century. 

 Continuing their pursuit of the Moors, the Portuguese initiated a series of somewhat warlike 

 exploratory voyages down the West African coast. Attempts to sail southward were for a long time 



