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SCIENCE. 



[N. S. Vol. XVI. No. 399. 



the discussion, Dr. von Bezold remarked 

 that the connection between the Fohn wind 

 and the number of ions in the air was now 

 being studied. The air brought down from 

 a great height by the Fohn carries more 

 ions to a lower level and there thus appeared 

 to be a relation between moimtain sickness 

 and the well-known physiological effects of 

 the Fohn. Professor Palazzo, of Rome, ex- 

 plained his photographic arrangement of 

 Exner's electrometer, for use in balloons, 

 and Dr.. Linke, of Potsdam, described the 

 measurements he had made in balloons to 

 determine the change of potential and con- 

 ductivity of the air. He had confirmed his 

 early residts that the potential was always 

 positive, but f oiuid the variation of the con- 

 ductivity in cloud strata depended upon 

 the weather conditions. The vertical mo- 

 tion of the balloon introduced complications 

 which made the dispersion observations 

 very difficult. On the request of Professor 

 Ebert, the Congress recognized the impor- 

 tance of executing electrical measurements 

 in balloons. The same speaker shoAved an 

 apparatus for determining the horizontal 

 magnetic intensity in a balloon without 

 knowing either the astronomical or mag- 

 netic meridian. This is not only of scientific 

 importance, but may be practically useful 

 to guide the aeronaut at night and when he 

 is in the clouds or over the sea. Dr. 

 Marcuse, of Berlin, then showed an instru- 

 ment for determining astronomically in a 

 balloon its position. Dr. Kassner, of Ber- 

 lin, suggested that kites and kite-balloons 

 might be employed in the following 

 scientific investigations: in physics for 

 the determination of the conditions affect- 

 ing the velocity of sound, in geodesy and 

 astronomy for researches as to the causes of 

 the variation in atmospheric refraction and 

 in meteorology for a study of the action of 

 'hail shooting.' Finally Director Ar.chen- 

 hold, of the Treptow Observatory in Ber- 

 lin, said that the volcanic eruptions in the 



West Indies may produce optical phenom- 

 ena similar to those following the Kraka- 

 toa explosion, namely, first brilliant sunsets 

 and then the luminous night clouds which 

 would be first perceived by aeronauts dur- 

 ing nocturnal ascensions. 



The Committee recommended that the 

 international ascents of balloons and kites 

 should take place, as heretofore, on the 

 first Thursday of each month, and the 

 ballons sondes should be liberated an hour 

 before sunrise in order that the instruments 

 may be unaffected by insolation and the 

 balloons may be seen when they fall to the 

 earth. The employment of the insulated 

 thermometer and of the sensitive metallic 

 thermometer already described were like- 

 wise advised. The president noted with 

 satisfaction the arrangements by which kite 

 flights would be made above the seas, lakes 

 and mountains, and hoped that the British 

 Government would aid in the investigation 

 of the great Asiatic monsoon region. The 

 Congress was then closed, but the Commit- 

 tee in executive session formulated reso- 

 lutions, among them a request to the 

 Reichschancellor for a subvention to defray 

 half the cost of the proposed German- Amer- 

 ican kite expedition to the tropics. 



The entertainments were a notable fea- 

 ture of the Congress. During a visit to the 

 Aeronautical Observatory of the Prussian 

 Meteorological Institute, at West Reinick- 

 endorf, a few miles north of Berlin, the 

 kites, kite-balloon and rubber ballons 

 sondes were sent up, one of the last at- 

 taining the unprecedentedly great height of 

 twenty kilometers. The following day, 

 after the adjacent establishment of the 

 Priissian Balloon Battalion, which is the 

 most modern and complete in the world had 

 been inspected, field manceuvres were exe- 

 cuted and the tune reqi;ired to bring the 

 kite-balloon on the field, inflate it and 

 send wp an officer to reconnoiter was found 

 to oceupj' but sixteen minutes. A number 



