AND THE ACTINIC CONSTITUTION OF TUK ATMOSPHERE. 



'Ji) 



strikiug, as by a mistake in our agi'et'iueut the exiuisure to the siiu lasted an liour 

 longer iu France tliaii in Finland. The latter ought, theref<M-e, to be somewhat 

 increased, in order to make the comparison moi'e just. We shall presently return 

 to the results marked iu the last coluuui. Mr. Elfving had worked only duiing 

 five days; the comparative expei'imeiits were therefore not iiumei-ous enough, and 

 by a common understanding another beginning was made in 1888. 



Here is the report of the experiments which T made in France, in the garden 

 of the Agronomic Institute, during the months of May and June, 1888. My official 

 duties prevented me from making them iu an unbroken series, and, moreover, I had 

 to leave out three observations during whicli a fierce wind suddenly s[)rang up and 

 covered my vessels with a layer of dust. 



PARIS. EXPOSURE FROM 8 A.M. TO 5 P.M. 



The correspondence between the degi'ee of combustion and the state of the 

 atmosphere is less striking in these observations, which were made in Paris, than in 

 those made in the country, wkich is less surprising when we bear iu mind the 

 incessant heterogeneity and variability of the air in a large city. The influence of 

 the spring season, however, to which reference was made before (page 14) is shown 

 in the relative magnitude of the figures of combustion. The figure 64 %, dated on 

 June 12th, is very exceptional. 



Here follow next the results obtained almost simultaneously by Mr. Elfving 

 at Helsingfors : 



