308 EXPLORATIONS OF THE UPPER ATMOSPHERE. 



ourselves, in compauy with M. Besangon and four other aeronauts, nad 

 landed with the balloon Touring Club just three months before. 



The material of the Aerophile was unhappily in a very deplorable 

 state. As the peasants who possessed themselves of it at the time of 

 its fall did not know how to read they did not think of opening the 

 envelope containing the instructions given by the aeronauts to the per- 

 sons who might find the balloon, which, in order to detach from the 

 trees upon which it had fallen, they tore in several places. The net 

 was torn to pieces and completely useless. As to the sheets covered 

 with lampblack wound about the registering cylinder, the peasants, 

 attaching no sort of importance to them, had detached them and thrown 

 them aside in a corner, where M. Hermite fortunately found them. 



The diagram which thus escaped those whom we can scarcely call 

 tlie rescuers of the balloon shows that the aerostat reached equilibrium 

 at a pressure of 115 millimeters of mercury, which corresponds to a height 

 of 15,000 meters according to the formula of Laplace, no correction 

 being made for the temperature of the air. The vertical velocity at 

 starting was about 8 meters per second, and the highest point was 

 reached in forty minutes. The velocity of descent was 6 meters per 

 second when near the ground. It was then twice as rapid as usual, a 

 fact which may be attributed to an accumulation of moisture upon the 

 envelope of the aerostat. 



The thermometer registered a minimum temperature of 60° 0. at 

 about C a. m., the barometric ]3ressure being then 160 millimeters of 

 mercury. 



This observation agrees completely with those that have been made 

 not only in a balloon but on the ground, for it has been shown that 

 under almost all circumstances a marked lowering of temperature 

 takes place a little before sunrise. Still, before relying absolutely upon 

 this, it would be well to assure ourselves that the registering apparatus 

 was sufficiently ventilated; for, in spite of the absence of every cause 

 due to heating during this nocturnal ascension, it is possible that 

 aeration plays a very important part in the precision of thermometric 

 observations. In order to remove these uncertainties there should 

 be, in subsequent experiments, comj^arative observations made with 

 several similar registering thermometers under various conditions of 

 aeration. 



As compared with the preceding ascent, the motion of translation of 

 the Aerophile was quite slow. The distance from Paris to Graide being 

 about 220 kilometers as the crow flies, and being traversed in four 

 hours and twenty-five minutes, the balloon traveled only 36 kilometers 

 an hour. 



v.— FOREIGN ASCENTS ON THE 14th OF NOVEMBER. 



As we have already said, three recording balloons and four mounted 

 balloons were released at different points on the night of the 14th of 

 November. The results of these experiments were as follows: 



The recording balloon of Strasburg, having a capacity of 350 cubic 



