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SCIENCE PROGRESS 



such data. "Weather" is mainly the product of the cyclonic 

 disturbances originating in the sea some distance from the 

 land. In our own case these disturbances apparently arise 

 in the North Atlantic, no doubt as the products of the irregular 

 heating of the atmosphere over the sea by masses of relatively 

 warm and cooling water. Such disturbances originating in 

 the Iceland area also have an appreciable effect on the weather 

 of the British area. But, unfortunately, there seems to be little 

 likelihood of the hydrographic investigation of the North 

 Atlantic from this point of view. 



Hydrographic Conditions and the Harvests 



It was shov/n by Otto Pettersson in 1896 that a close 

 connection between the hydrographic condition of the sea and 



Fig. 5. — Correspondence between the temperature of the surface waters of the Sognefjord 

 section in May, and the growth of the Fir in Norway. 



(From Helland-Hansen and Nansen, loc. cit. p. 348.) 



vegetation phases on the adjacent land was a priori probable. 

 He showed, for instance, that the earlier or later flowering of 

 the Coltsfoot (Tttssilago Farfara) was to be associated with 

 the variations from the mean in the sea-temperature off Norway 

 in the February of the same year. But the coastal sea- 

 temperatures do not, as we have seen, afford a very good 

 expression for the hydrographic changes taking place in the 

 sea in general, and Pettersson's suggestions have only been 

 fully borne out since the data accumulated during the last 

 few years became available. 



Holmboe (quoted by Helland-Hansen and Nansen) showed 

 that there was a close correspondence between the growth of 

 the Fir (Pinus sylvestris) in Norway and the meteorological 

 conditions during the previous year — when the buds were 



