THE PROGRESS OF AERONAUTICS. 189 



of the skillful officers who havt> been charged by their governments 

 with the creation and functioning of these services, it must be con- 

 fessed that important desiderata still remain. Thus it is possible now 

 to g-et away from a ])esieged place almost without risk, l)ut to get in 

 again is quite another thing, for this second problem depends upon 

 the famous one of steering a balloon, a problem which began to be 

 solved in 18S() at Chalais-Meudon, but of which the complete solution 

 is still in futuro. 



Since 1889 this great question, how to steer a balloon, has been con- 

 tinually agitated. Yet we must confess that while highly interestino- 

 essavs have been made, which merit all our S3'mpathy, no decisive step 

 has been taken. In Berlin two overbold experiments have resulted 

 tragically. Yet experimenters have not been discouraged. ]M. Santo- 

 Dumont is even now preparing to contest the prize of 100,000 francs 

 that M. Henrj^ Deutsch has founded at the Aero Club; and Count 

 Zeppelin is making a new and grand attempt on the Lake of Constance 

 with a partitioned balloon 117 meters long, moved by two petroleum 

 engines acting on four screws. 



But though the steering of balloons is the first and most important 

 problem, yet it must not be forgotten that it is likewise of very high 

 interest to perfect aeronautics, whether in the direction of rising to a 

 great height, or of remaining aloft as long as possible, or of going to a 

 point named in advance. For, aside from the immediate end pursued, 

 these ascensions lead to improvement in the instruments and methods 

 of aerial navigation. As examples, ma}' be mentioned the remarkable 

 voyage of Count de Castillon de St. Victor from Paris to Sweden, in 

 which the balloon traveled more than 800 miles (1,800 kilometers), and 

 that of the Count de la Vaulx, who succeeded in keeping his aerostat 

 aloft for more than thirty hours without landing. Again, we may 

 instance the voyage of M. Mallet, who, with the same balloon, made in 

 a week the tour of France, landing each day. In the matter of height, 

 the prize, or, to use the language of sport, the record belongs to Mr. 

 Berson, attached to the Meteorological Jnstitute of Berlin, who several 

 times rose to 26,000 feet (8,000 meters) and once as high as 30,000 feet 

 (9,150 meters), which is higher than the highest summits of the Hima- 

 layas. It is noteworthy that it was by the system of inhaling oxygen, 

 which had already been tried in France, that Mr. Berson was enabled 

 to l)ear the rarification of the air at such extraordinary heights. 



Scientific ascensions have been nmch practiced in Germany, being 

 stimulated l)y the Berlin Aerial Navigation Society and by the liberality 

 of the Emperor. During the last five years no fewer than seventy-five 

 such ascensions have Ijeen made, and the results have been discussed 

 in the recent great work of Messrs. Asmann and Berson. 



The heights attained l)y these balloons carrying observers are, how- 

 ever, necessarily limited. Even with the judicious use of oxygen, the 



