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HKRDMAN 



[CHAP. 6 



The collection of surface samples and the determination of surface tempera- 

 ture do not always receive the care with which subsurface observations are 

 taken. Too often the sample is taken in a canvas bucket and the temperature 

 read after an appreciable time. The errors thus introduced can be considerable 

 and, in an effort to overcome them. Lumby (1927, 1928) has described an easily 

 handled sampler which can be towed alongside a ship and which automatically 



Fig. 1. N.I.O. plastic water-sampling bottle, with reversible frame for thermometers. 



collects a clean sample. The thermometer cannot wholly be withdrawn when 

 reading it and part insulation of the sampler allows an interval of at least 4 min 

 for reading. More recently, Lumby and Haes (MS, 1957) have devised a simple 

 near-surface sampler which can be fitted in a circulating pump intake in the 

 smallest ship. This instrument permits a constant flow of water through 

 the whole apparatus. The temperature is read from a thermometer fixed in 

 the flow. If the surface temperature only is required this can automatically be 



