December ii, 1902] 



NA TURE 



i39 



and during the night hours there are large inversions of 

 temperature. In anticyclones, large inversions occur in the lower 

 strata and a rapid decrease of temperature in the higher strata. 

 General Rykatchef exhibited an anemometer, constructed by his 

 assistant, Mr. Kusnetzof, for the registration of wind pressure 

 during kite flights. The instrument has bridled Robinson cups 

 which act like a dynamometer and record the gusts of wind 

 on a revolving drum. In closing, the speaker announced that 

 the Czar had given a considerable sum of money for the con- 

 tinuation of this investigation of the different strata of the atmo- 

 sphere in Russia by means of balloons and kites. 



M. Teisserenc de Bort, of Paris, presented the results of his 

 observations of the decrease of temperature in the high atmo- 

 sphere, as obtained from the ascensions of 25S ballons-sondes, 

 which had reached or exceeded 1 1,000 metres, the total number of 

 ascensions being 540, all of which were made at night to avoid 

 the effect of insolation. The concordant and remarkable result 

 is that, in the layer between 8000 and 9000 metres, the decrease 

 of temperature becomes slower, ceasing entirely at 11,000 

 metres, while above that height a warming may set in, with fluctu- 

 ations of 1° to 3 centigrade, making the temperature here on 

 the average nearly constant. In the summer, this isothermal 

 layer apears to lie somewhat higher, or between 13,000 and 

 14,000 metres. It is lower during the prevalence of a depres- 

 sion, but 4000 metres higher during a high pressure, so that 

 the zone exceeds the height of the cirrus clouds. The lowest 

 temperatures, occurring in a high pressure, were -67° and 



- 72 , but in March the exceptionally low temperature of 



- 75° centigrade was observed. Whether the absolute mini- 

 mum of temperature has been reached here requires further 

 proof, and as to the cause of this striking phenomenon there 

 are only conjectures. Have we at these great heights atrial 

 conditions working on a grand scale, where the cyclonic whirls 

 of the lower atmosphere do not penetrate and the currents flow 

 uninterruptedly ? 



Prof. Assmann said that the observations of the Berlin 

 Aeronautical Observatory, although obtained by a somewhat 

 different method, led to the same conclusion as that which had 

 been reached at Trappes. Above 10,000 metres, the temperature 

 oscillates and does not appear to decrease, although beyond the 

 variable stratum, at 1 7,000 metres, and recently as high as 19,500 

 metres, the temperature was again found to decrease, so that the 

 possibility of an absolute minimum of temperature is by no 

 means excluded. The Berlin observations were executed with 

 specially constructed balloons of Para rubber, which entirely 

 avoided in the daytime the influence of solar radiation on the 

 instrument, which was enclosed in double polished tubes. 



Prof. Palazzo, Director of the Central Meteorological Office 

 at Rome, announced that Italy would now participate in the 

 international scientific exploration of the atmosphere. Through 

 the aid of the Minister of Agriculture, three stations for kites 

 are proposed ; one on Mount Cimone (2165 metres), another 

 on Etna (2942 metres) and a third outside of Rome, near the 

 Fort of Monte Mario. The Minister of War has ordered that the 

 ascensions by officers of the balloon corps shall take place on 

 the days of the international ascents. Information was given 

 about the observatory for the study of the physics of the atmo- 

 sphere, now in construction on Monte Rosa at a height of 4560 

 metres, which is expected to be completed next summer. In 

 connection with this communication, there was a discussion con- 

 cerning the interest of scieniific aeronautics in physiological 

 invesiigations, which will form an important part of the work of 

 the high-work observatory mentioned. 



Prof. Assmann, Director of the Aeronautical Observatory 

 of the Prussian Meteorological Institute, described his regis- 

 tration balloon of caoutchouc or Para rubber, which was one 

 of the novelties of the meeting. The ordinary balton-sonde^ 

 made of silk or paper and open at the bottom, has the great 

 disadvantage that, when it approaches equilibrium in the upper 

 strata of the atmosphere, its velocity of ascent decreases and 

 the effect of insolation on the thermograph becomes greater, 

 without it being possible to determine afterwards the place 

 where the solar disturbance began during the ascent or where 

 it disappeared during the descent ; in fact, it is only in certain 

 cases that we can distinguish between the insolation influence 

 and the curious thermal anomalies that have been described 

 by Teisserenc de Bort and Hergesell. The use of a closed 

 balloon made of elastic material has this advantage, that in 

 proportion as the enclosed gas expands, the ascensional force 

 is increased, so that the balloon rises faster with augmenting 



NO. 1728, VOL. 67] 



height until it bursts, and then falls to the ground with dimin- 

 ishing velocity, because checked by a parachute. The meteor- 

 ograph of Prof. Assmann has no clock movement, the time being 

 unimportant ; but a disc is turned by the metallic thermometer 

 while the barometer draws a pen horizontally across the disc, 

 and so the spiral curve indicates heights and corresponding tem- 

 peratures. The apparatus exhibited weighed but 380 grams, and 

 with the protecting basket 500 grams. Since ink would freeze 

 at great elevations, the trace is made by a pen containing a solu- 

 tion of saltpetre, which writes on the disc coated with lamp- 

 black, treated with a solution of " tonsol." The chemical reac- 

 tion gives a red trace that cannot be obliterated by handling or 

 by immersion in water. The time required for an ascent to 

 15,000 metres is about one hour and for the descent two hours, 

 so that the balloons do not travel very far and are usually re- 

 covered within three days. The diameter of the envelope at 

 the start is I or 2 metres only, and it does not require to be 

 completely filled with hydrogen to exert the necessary initial 

 lift of 2 or 3 kilograms. 



Dr. Valentin, of Vienna, spoke on the sluggishness of ther- 

 mographs in registration balloons. Prof. Hergesell believed 

 that it was better to employ the most sensitive and accurate 

 thermometers rather than to try to determine the corrections for 

 sluggishness. He exhibited such an instrument, as did M. 

 Teisserenc de Bort. The French instrument has the Bourdon 

 tube insulated by a block of hard rubber, which prevents the 

 injurious conduction of heat. Comparisons between an instru- 

 ment insulated in this way and one not insulaied gave differ- 

 ences which increased with the height of the balloon and at 

 12,000 to 14,000 metres reached 6", an amount that justified the 

 insulation. 



At the third meeting, the subject of kites and kite stations 

 was opened with a paper by the writer on the exploration of 

 the atmosphere over the ocean. The use of the kite on land 

 is limited to favourable circumstances, since the wind must have 

 a velocity of at least 5 or 6 metres per second to raise the kites 

 and cannot exceed a certain maximum strength without endan- 

 gering the wire by an excessive pull. At sea, however, the 

 motion of a steamer at a velocity of 10 or 12 knots will almost 

 always produce a suitable kite wind, if it does not already 

 exist. In ojder to demonstrate this, in August, 1901, the writer 

 crossed the North Atlantic on a steamer and found five out 

 of eight days suitable for flying kites. Only on one day was 

 the relative wind too light and on two days too strong, but 

 the wind would always have been favourable had it been pos- 

 sible to alter the course of the vessel. These successful results 

 led the writer to propose a meteorological kite expedition to 

 the trade wind and equatorial regions of the Atlantic Ocean, 

 where almost nothing is known of the upper currents. To 

 defray part of the expense, application has been made to the 

 Carnegie Institution lor a grant of 10,000 dollars, but it was con- 

 sidered that the recommendation of the present Congress might 

 aid in securing favourable action. Applause snowed the 

 approval of the meeting, which was voiced by Drs. von Bezold 

 and Hergesell. The former, especially, pointed out the im- 

 portance and the pressing need of meteorological observations 

 over the ocean, where, in consequence of other methods of 

 warming and cooling the air, very different conditions must 

 exist than prevail over the land, and our ignorance of them is 

 no longer to be tolerated. Prof. Koppen, of Hamburg, ex- 

 pressed himself in a similar manner, and made the interesting 

 announcement that, according to the programme of the Scan- 

 dinavian H^drographic Congress to explore the Baltic and North 

 seas in the interest of the fisheries, four cruises a year were 

 proposed on which meteorolc 'gists would be given an opportunity 

 to study the atmosphere above these seas. Prof. Wagner, 

 of the University of Gbttingen, said that the Goitingen 

 Society of Sciences had, at the request of the Aeronautical 

 Committee, furnished the geophysical expedition which was 

 sent to Samoa about a year ago under the leadership of Dr. 

 Tetens with kites and instruments, in order to obtain meteor- 

 ological observations above that island and on the return voyage 

 over the Pacific Ocean. Dr. Hergesell mentioned that on the 

 Lake of Constance meteorological kite flights were to be under- 

 taken, Count von Zeppelin lurnishing ihe vessel and the meteor- 

 ological service of Alsace-Lorraine the apparaius. General 

 Rykatchef promised, on the part of the Russian Government, 

 that similar observations would be executed over the norihern 

 portion of the Baltic as well as over the Black Sea. On the motion 

 of Dr. Hergesell, the plan of Mr. Rotch for a meteorological 



