Decreased Pressure 973 



strata in movement; to measure the variations of temperature, elec- 

 tricity, humidity, the chemical composition of the air, at different 

 heights; to analyze the constituent elements of the stars, by rising 

 above the sort of screen which the lower strata of the atmosphere 

 form: such were the principal problems which they had set them- 

 selves. The utility of ascensions to great heights has been denied: 

 that is denying evidence. Everything leads us to believe that the 

 balloon, by its power of ascension, can carry the observer beyond the 

 extreme limits where the highest clouds float. Now what source of 

 prosperity for humanity could be compared to the unfailing predic- 

 tion of weather? How can we hope to reach that goal without know- 

 ing thoroughly this region where rain, snow, and hail are formed, 



Fig. 89— Croce-Spinelli. 



and where the winds and storms are engendered? And how can we 

 know this region without ascension to a great height, which permits 

 us to reach its domain and, if I may speak thus, to dissect the atmos- 

 phere? 



I owed these explanations to the Society of Aerial Navigation; 

 I owed them to the memory of our unhappy friends. Furthermore, 

 no one was deceived. Everyone understood that these were men of 

 science, who died doing useful scientific research, and that is the sec- 

 ond reason which explains the emotion aroused by their death. 



There is a third, more thrilling, more poignant perhaps. Let us 

 go back in thought five years, to the terrible winter. Paris is enclosed 

 in a circle of iron; all communications are cut off; on land, unsur- 

 mountable obstacles; nets bar the river. But the air is left, this new 

 route opened by a Frenchman, Montgolfier, on which a Frenchman 

 was the first to venture, Pilatre du Rozier; brave men — M. G. Tis- 

 sandier was among them — rose into the air, braving a thousand 



