( 78 ) 



for tluit imiyc'le during iiny single twitcli is indicated by ^1. Arid 

 in tills case again it is sliown tliat our law concerning tiie relation 

 between stimulus and effect enables iis to represent with snfficient 

 accuracy the increment of effect whenever the stimnhis is increased. 

 At present we only Avish to state this fact without enterhig into 

 any details about its theoretical significance for our knowledge of 

 the course of isometrical contractions. 



Meteorology. — At the chairman's proposal it was resolved to 

 insert in the Proceedings the following Ed'tract from the 

 Report made in the e.ctraordlnarij meetlmj held this day by 

 the committee for a/rardim/ the Buys-Ballot Medal, considimj 

 of Messrs. Julius, IIaga, Zeemax, van der Stok and Wind. 



In the meteorological literature of late years one definite line of 

 development in this science has come to the front in such a degree 

 that, in the o|)inion of the committee, it is obvious to award the 

 Buys-Ballot Medal for this time to a representative of this peculiar 

 branch of meteorological investigation. 



The branch referred to is one of mainly experimental investigation. 



In the opinion of some the material collected by the meteorologists 

 during a long series of years grows so tlangerously extensive that, for 

 instance, Professor Schuster could not help in the last meeting of the 

 British Association expressing a wish, that the meteorologists might 

 stop their observations for some ^\\o years and during that time 

 might unanimously try to assimilate the materials in store and to 

 compose a reasonable programme. Schuster in expressing a wish, 

 as to stopping the observations, cannot have been in full earnest, as 

 he will grant too that the series of observations, partly as material 

 for climatic studies, partly as a basis and a test for future theories 

 have a permanent Aalue and should not be rashly interrupted. 

 Ne\ertheless it is true that, in order to prevent w^aste of capital 

 and labour and to avoid the loss of valuable data, it is very 

 desirable, in continuing former series of observations, to constantly 

 keep in view their value and not to plan others but on reasonable 

 grounds. 



Yet, rather a short time ago the material referred to above, 

 however extensive, showed an important deficit. Most obviously it 

 did so, when considered as the foundation of a theory about the 

 great problems of meteorology, the general circulation of the atmos- 



