EXPLORATIONS OF THE UPPER ATMOSPHERE. 315 



during the asceut of the 18th of February on a normal military balloon 

 having a capacity of 560 cubic meters, used for captive ascents in the 

 army. The weight of this aerostat, with its attached instruments, was 

 exactly 225 kilograms. 



This aerostat was picked up in the little village of Screen, 150 kilo- 

 meters to the east of Berlin, 70 kilometers to the east of the city of 

 Frankfort on Oder, and in the neighborhood of the little village of 

 Meseritz, department of " Ost Stenberg." The ascension lasted from 

 11.04 to 3.20. The military balloon rose to a height corresponding to a 

 pressure of 248 millimeters, finding a temperature of — 42°, which gives 

 an altitude, when corrected, of 8,850 meters above the level of the sea. 

 The imperial Geodesic Institute had established three stations pro- 

 vided with theodolites. The geodesists took some 30 observations, 

 which gave for the maximum altitude 8,800 meters, a coincidence truly 

 remarkable, and which maybe considered as a verification of Laplace's 

 law of barometric heights. 



There were also two mounted balloons released. The first, which 

 had a capacity of 1,300 cubic meters and was inflated with illuminating 

 gas, was called the Condor. It carried M. Juring, a physicist attached 

 to the Meteorological Institute, and was directed by M. vonKehler, an 

 officer of the balloon service. The Condor, starting at 9.40, rose to a 

 height of 3,258 meters where the temperature was — 7.5°. It descended 

 at 4.30 p. m., 250 kilometers east of Berlin, at Schneidemuhl, in the 

 duchy of Posen. 



M. Berson, a member of the International Commission, made an 

 ascent with a military balloon having the same weight and volume as that 

 of the recording balloon. He descended at ISTaeckel, 295 kilometers N. 

 4° E. of Berlin, after having reached an a'ltitude of 4,632 meters, where 

 he encountered a temperature of — 13.8° and air almost saturated with 

 humidity. The voyage lasted seven hours and forty seven minutes. 



-Thebarometric andthermometric curvesof the recording balloon could 

 be read very well, although the diagrams were covered with a great 

 number of spots produced at the time of the landing and in returning 

 to Berlin. 



During the month of March M. Assmann intends to make a private 

 experiment, with illuminating gas and a discharge sac, as well as new 

 instruments. 



The thermometric tracings are found to be affected with a great 

 number of little serrations that seem to have an almost periodic char- 

 acter, being reproduced every fifteen or sixteen minutes. M. Assmann 

 attributes them to the fact that the protecting basket does not give 

 sufficient protection, and supposes that they are caused by a rotation 

 of the balloon. 



At Strashurg. — The recording balloon Strasburg was released during 

 a thick fog, and, like Aerophile III, was immediately lost to sight. It 

 was not until after eight days of search that it was found attached to 



