194 



SCIENCE 



N. S. Vol. XXX. No. 763 



by observing pilot-balloons with theodo- 

 lites. 



The Prince of Monaco welcomed his 

 guests to the new Oeeanographic Museum, 

 which he hoped would become a repository 

 for the results of soundings of the air as 

 well as of the sea, and to his yacht, Prin- 

 cesse-Alice, on which were made marine and 

 atmospheric sotmdings from the equator 

 to beyond the Arctic Circle. In speaking 

 of the last the prince described the launch 

 and recovery of a ballon-sonde at sea. 



At the business meeting which followed, 

 Professor Hildebrandsson was named vice- 

 president of the conference. The death of 

 Professor Pernter was announced and Pro- 

 fessor Trabert, his successor as director of 

 the Austrian Meteorological Office, was 

 chosen a member of the commission. Other 

 new members elected were: M. Vincent, 

 head of the Belgian Meteorological Service ; 

 Dr. Kleinschmidt, in charge of the Lake 

 Constance Kite-station; Captain Eyder, 

 director of the Danish Meteorological In- 

 stitute ; Professor B jerknes, of Christiania ; 

 Dr. Bamler, of Munich; the directors of 

 the Russian observatories at Irkutsk, Tiflis 

 and Ekaterinburg, and these military aero- 

 nauts : Captains Voyer and Bouttieaux, of 

 France: Le Clemfint de St.-Mareq, of Bel- 

 gium, and Colonel Capper, of Great 

 Britain. 



The program for the conference was in- 

 tended to include: (1) technical questions 

 relating to balloons and instruments; (2) 

 methods, organization and equipment of 

 expeditions; (3) reports of researches dur- 

 ing the preceding year ; (4) other questions, 

 including new projects. 



The International Commission on the 

 System of World-stations, a subcommittee 

 appointed by the International Meteorolog- 

 ical Committee, also met in conjunction 

 with the Aeronautical Commission. 



In the first group. Dr. Assmann, director 



of the Prussian Aeronautical Observatory 

 at Lindenberg, described a new process of 

 making iallons-sondes by dipping in a rub- 

 ber solution instead of cementing sheets of 

 I'ubber. The particles of dust in the latter 

 cause the pores to open, but the dipped 

 balloons expand five or six diameters with- 

 out losing gas or bursting, permitting a 

 greater height to be reached or a smaller 

 balloon to be used. The parachute cords 

 by friction on the rubber weaken it, or if 

 two balloons are attached tandem, the 

 smaller sets up oscillations injurious to the 

 record ; therefore Dr. Assmann proposes to 

 put one balloon inside the other, one of 

 them bursting on reaching the maximum 

 altitude. He now employs a rubber cap- 

 tive-balloon of 14 to 17 cubic meters ca- 

 pacity, which loses no gas and therefore 

 does not present pockets to the wind, and 

 when carrying wire of 0.6 mm. diameter 

 can reach an altitude of 4,000 meters. To 

 avoid the chemical effect of insolation on 

 the rubber the upper portion of the net is 

 covered with a yellow fabric. A discussion 

 followed as to the advantages of rubber and 

 gold-beaters' skin for captive-balloons. 



Dr. Assmann in another paper described 

 an instrumental method to verify if, in the 

 isothermal layer, the ventilation of ther- 

 mometers is sufficient. While the upper 

 inversion was shown as early as 1893 by 

 the observations of Hermite and Besangon, 

 yet for a long time it was attributed to 

 insolation. This disturbance was later 

 avoided by night ascensions and the descent 

 of the balloon accelerated through letting 

 gas escape by clockwork. The rubber bal- 

 loon gives a very nearly constant velocity 

 of ascent and this ventilation and a bright 

 metal casing around the thermometer are 

 generally thought sufficient. While it is 

 doubtful whether extremely rare air can 

 carry off heat from the thermometric 

 strip, if there is no change when an artificial 



