EXPLORATIONS OF THE UPPER ATMOSPHERE. 309 



meters, was filled with illuminatiug gas having an ascensional power 

 of 800 grams j)er cubic meter, and was released at 2 a. m. An hour and 

 a half later the api)aratus fell in the Biack Forest, at the foot of Mount 

 Hornsgrinde, 30 kilometers northeast of Strasburg, The maximum 

 height attained was 800 meters, and the barometric diagram shows a 

 Ijerfect regularity, while that of the thermometer, undoubtedly falsified 

 by some derangement of the mechanism, shows a rise of temperature 

 not corresponding to any natural phenomenon. M. Hergesell, struck 

 with this irregularity, has since that time thought proper to have M. 

 Eichard modify the construction of the thermometric reservoir, iu order 

 to prevent the recurrence of a similar accident. 



The recording balloon Cirrus, of Berlin, received only 150 cubic 

 meters of pure hydrogen gas, its capacity being 250 meters. It carried 

 a barothermograph and a Richard barograph, as well as a thermo- 

 graph of German construction. It was released at 2.51 a. m., local time, 

 and its descent occurred a short time after in the Grilnenwald, a forest 

 situated a few kilometers to the southeast of Berlin. The maximum 

 altitude attained was only 5,800 meters, the balloon having exploded 

 in the air, a phenomenon that was by no means surprising when we 

 consider the vacuum that existed in the aerostat at the time of depar- 

 ture. M. Assmann adds, also, that the Cirrus was old and Avorn by 

 reason of prolonged service. 



The recording balloon released at St. Petersburg by M. Kykatcheff 

 had a similar unfortunate fate, for it burst at an elevation of 1,500 

 meters. It was released at 4 a. m., local time, and the voyage lasted a 

 quarter of an hour. Temperature at starting, —5°; at the culminating 

 point of its ascent, —13°. 



The mounted balloon Buzzard, having a capacity of 1,300 cubic 

 meters, was released from the aerostatic park of Schoneberg, at Ber- 

 lin, at 2.48 a. m. It had received 1,000 cubic meters of pure hydrogen, 

 and was accompanied by Lieutenant Von Keller, an officer of the bal- 

 loon service, and by M. Berson, a well-known meteorologist and 

 aeronaut. The voyage was a very remarkable one; it lasted eleven 

 hours and thirty-seven seconds, and ended on the seashore at Volk- 

 hagen, near Ribnitz, in Mecklenburg. The average velocity was 

 5 meters per second, the maximum height 5,600 meters, which was 

 attained at 11.43 a. m. The lowest temperature observed at this 

 height was —24.4°, by means of an aspiration apparatus invented by 

 JM. Assmann. 



At St. Petersburg the balloon Vannesky, having a capacity of 1,000 

 cubic meters, started at 4.45 a. m., accompanied by MM. Kowenko and 

 Semkowski. The lowest temperature observed was —22.8° C, at the 

 height of 3,500 meters, and —23° at 4,560 meters for the mercurial ther- 

 mometer. With the alcohol thermometer the lowest was —27.2° at 3,840 

 meters. The descent was made at 11.30 a. m. near Pskow. The first 

 rays of the sun reached the aerostat at 7.48, and somewhat disturbed 

 the course of the meteorological observations. 



