50 ANNAL."^ NEW YORK ACADEMY OF iiCIENCES 



1873-1882 is a typical example of a widely spread-out macropleion, while 

 the decade of 1883-1892 shows a predominant macromeion. 



The next problem to be taken into consideration is whether the maxi- 

 mal deveh)})ment of macropleiona occurs simultaneously on the different 

 continents. 



I have already published the departure maps of the five decades from 

 1851-1900 for Europe/'^ but I think that it would be useless to make 

 comparisons without the aid of consecutive maps. Therefore it may be 

 that the increase in temperature is simultaneous on both sides of the 

 Atlantic or that, on the contrary, there are compensations, — it may also 

 be that there are correlations in the movements of the macropleions or 

 even pendulations of a higher order. I have to leave these questions 

 unsolved. They concern the last and most important of the three prob- 

 lems of long-range climatic variations mentioned at the beginning of 

 this discussion. I may venture to add that this is also the only prol)lem 

 which remains to be solved, because the second problem concerning long- 

 range variations, mentioned above, does not harmonize with the dynam- 

 ical conception of climatic variations which must be admitted. 



European Temperature Data for 1900-1909 



It is really astonishing that after all the efforts which are made, all 

 over the world, to organize and maintain meteorological stations, mainly 

 for the purpose of collecting data, the actual results of the work which is 

 done are as inaccessible as they are. 



It seems to be a very simple matter to take into consideration the 

 European temperature data for the years 1900-1909 in order to discuss 

 the results, but it is not so. I had in view the yearly means of these 

 years. One would think that in a town like Xew York City all the pub- 

 lications where these figures are recorded could be easily found. This is 

 a mistake. In order to have the necessary data I had to obtain them by 

 correspondence. I express therefore my thanks to the Directors of the 

 different meteorological institutions who helped me in my work by pro- 

 viding me with the necessary data. 



In the following tables (Table II) I give the annual means in form 

 of departures from the means of the decade 1900-1909. All the figures 

 are degrees centigrade. 



" Op. cit., pp. 40-42. 



