314 EXPLORATIONS OF THE UPPER ATMOSPHERE. 



small quantity of carbouic acid found in excess of that in normal air 

 (0.033 in place of 0.029) is due to the oxidation of the oil employed, 

 which may have produced the tenth of a milligram of excess which 

 corresponds to the volume of air employed. 



In the same way the smaller quantity of oxygen found than that of 

 normal air (20.79 in place of 20.96), and which represents for the volume 

 of air collected 3 milligrams, may come from the absorption of that gas 

 by the oil of the cock or indeed by the metallic surface of tinned 

 copper. 



By eliminating the possible causes of error in new ascensions, we 

 may hope to show with certainty whether or not real differences exist 

 in the air taken at various altitudes; for the methods of gas analysis 

 are to-day so perfect, thanks to the efforts of M. Th. Schloesing, jr., that 

 they show extremely small differences; if, in fact such differences exist. 



But as it is to be expected that in the regions of the atmosphere 

 possible to explore by means of recording balloons the air is still sub- 

 ject to that intimate mixing that renders the air of lower regions prac- 

 tically uniform, we ought to expect to find the differences in its com- 

 position very slight, and only to be established with certainty by taking 

 the most minute precautions. 



The results of this fine experiment were the subject of a note pre- 

 sented to the Academy of Sciences and read at its session of the 8th 

 of March by MM. Hermite and Besan^on at the same time that there 

 were presented communications on the subject by MM. Cailletet and 

 Muntz, as we have said above. These persevering investigators were 

 warmly felicitated by the whole assembly, and upon the motion of M. 

 Berthelot a grant of 1,200 francs was made to MM. Hermite and Besan- 

 ^on, in order that they might pursue their interesting researches, which 

 will reveal still other unknown facts in meteorology and the physics of 

 the globe. 



VII.— FOREIGN ASCENTS ON THE ISTH OF APRIL, 1897. 



At the same time that the Aerophile was ascending from the works of 

 La Yillette several ascensions were going on in different cities, and we 

 will pass them rapidly in review, so as to understand the results obtained 

 by foreign observers. 



The ascensions at Berlin were undertaken by the military aerostatic 

 establishment at Schoneberg, in presence of the Emperor and the 

 Empress of Germany, as well as the ambassadors of France and Rus- 

 sia. Like those of the 14th of ISTovember, they will be the subject of a 

 circumstantial report, which M. Assmann has drawn up for the Emperor. 



The recording balloon, Cirrus II, having exploded in the preceding 

 experiment of November 14, 1896, because the net was not sufficiently 

 strong, it was not thought prudent to completely inflate the aerostat. 

 The envelope could not unfold with a speed corresponding to the dilata- 

 tion, and the aerostat was torn. The barograph and thermograph, 

 which were attached to a protecting basket, were saved and placed 



