is8 



NA TURE 



[December 15, 1898 



gives the position for 1900 as R.A. loh. 6"8m., Dec. +20° i6m., 

 which is gm. following, and 38' south of that given by Den- 

 ning. Some peculiarities of the photographed trails were that 

 they attained a maximum and then diminished as rapidly as 

 they increased, sudden changes due to explosion were well 

 shown, the trail was sometimes surrounded by a sheath of 

 light, and lastly, in one case the trail remaining after the meteor 

 had passed was recorded. 



ASTRONOMICAL CONGRESS AT BUDAPEST 

 A S was announced in X.\ rtRE of August 25, the International 

 Astronomical Association (Aslionomisilu Gcsellschaft) held 

 its seventeenth Congress at Budapest at the end of September. 



The meeting was an unusually large one, and the reception 

 by the Hungarian colleagues and the scientific and political 

 authorities was exceedingly cordial. There were present, amongst 

 others, the directors of the Observatories of O'Gyalla (von Kon- 

 kolv), Hereny (von Gothard), Kalocsa (Father Fenyi, S.J.), 

 Vienna (Weis?), Munich (Seeliger), Karlsruhe (Valentiner), 

 Heidelberg (Wolf), Gottincen (Schur), Jena (Knopf), Berlin 

 (Koerster). Breslau (Franz), Bamberg (Hartwig), Turin (Torro), 

 Upsala (Duner). Besides these, many well-known astronomers 

 attended, such as Muller, of Potsdam ; Nyren, of Pulkova : 

 Pechule, of Copenhagen ; Schrother, of Chrisliania ; Kreutz, 

 director of the International Bureau at Kiel, and of the Asti-otw- 

 niische Nachriihlen ; Bauschinger, director of the Institute of 

 astronomical calculations of Berlin, and many others. The 

 ab.sence of English and French .astronomers, many of whom 

 form part of the Society, was much regretted, and perhaps it is 

 due to this (act that the Congress, out of natural reserve, ab- 

 stained from raising the question of the fundamental stars and 

 constants, resolved, perhaps too hastily, by the Conference at 

 Paris in 1S96. 



The first meeting was opened by President Seeliger on 

 September 23, in the large hall of the Academy of Science, 

 where all the subsequent meetings were also held. \'on 

 Wlassics, the Minister of Education, who afterwards offered 

 lunch to the members of the Congress, the burgomasters of Buda- 

 pest, and Baron Eotviis, President of the Academy, well known 

 for his experiments on gravitation, attended. 



In the meetings of September 25, 26 and 27, besides other 

 afi'airs of the ordinary business of the Society and the confirm- 

 ation of the members of the Presidency, retiring by seniority, 

 many scientific subjects, briefly referred to here, were discussed. 

 Prof. Schiir described the new reductions of the observations of 

 planets and comets, made at Bremen by Olbers. Such reduc- 

 tions are made after the original notes of Olbers, placed at the 

 disposal of the Gottingen Olwervatory. Dr. A. Stichtenoth, 

 together with Prof. Schiir, takes part therein. In the first place 

 are discussed the ileterminations of time made by Olbers through 

 observations of the setting of the principal stars behind the 

 vertical side of the tower of the observatory, then the mea.sures 

 of the radius of the circular micrometer adopted, by the medium 

 of the observations of couples of stars applied to the comparison 

 with one particular comet ; and lastly, these same planetary and 

 cometary observations. In the published papers the times of 

 the observations and the distances along the circle of declination 

 of the comet and the comparison stars from the centre of the 

 ring will be given. It is hoped that it will be possible to place 

 these important materials at the disposal of astronomers during 

 next year. 



Dr. Bidschof, of the Imperial Observatory of Vienna, gave an 

 account of some catalogues completed by him. These contain 

 a list of the nebulae that were determined micrometrically at the 

 observatory of \ienna up to the end of 1897, besides a stellar 

 catalogue, containing the results of the new observations of the 

 southern stars of Santini, executed at the Viennese observatory. 



Dr. Brendel, of Gottingen Observatory, referred to the publica- 

 tion of Gauss's works. Soon after the death of Gauss the editing 

 of his works was confided toProf.Schering, of the Royal Academy 

 of Gottingen. Schering pulilished six large volumes, but did not 

 succeed in completing the publication, so that, besides the great 

 part of astronomical subjects published in the sixth volume, and 

 the "Theoria Motus," printed in the seventh, the numerical dis- 

 cussion of the perturbations of the motion of Pallas, which 

 will occupy the remainder of the seventh volume, remained 

 unedited. Concerning this, it is necessary to note that. 

 Gauss having left an enormous quantity of material (above half 



NO. 1520, VOL. 59] 



a million of figures) on this subject, without sufficient explan- 

 ation, the reconstruction of the mode of these calculations 

 becomes very difficult, though not impo.ssible. The so-called I 

 libration, connected with the curious jihenomenon, by which' I 

 seven evolutions of Jupiter correspond exactly to eighteen of 

 Pallas, presents special interest. The eighth volume will con- 

 tain additions to all the materials of mathematics and physics 

 dealt with in the fifth. Finally, the ninth volume will be 

 concerned with biographical matters. 



Prof. Franz demonstrated that the lunar globe previous to 

 its solidification must have been elorvgated in the direc- 

 tion of the earth by the tides produced by our planet. Whilst 

 the theory of tides and the physical libration assigns to such 

 elongation the small amount of o'oooi of the radius, Gussen, from 

 the me.isure of two lunar ])holographs in different librations, 

 obtained the considerable elongation of 0'0500. To eliminate 

 such contradictions between the theory and the observation; 

 Prof. Franz has measured five lunar jihotographs from the Lick 

 Observatory in various combinations, and found an elongation of 

 the lunar globe of 0*0027. Thus a nearer approach to the 

 theory is reached, which, however, cannot result in complete , 

 accord, through the want of homogeneity in the lunar mass. 

 Hansen put forward the hypothesis that the opposite part of the 

 moon was deeper, so that it had gathered on itself water and 

 air, thus rendering animal and vegetable life possible. On this 

 hypothesis a lively and interesting discussion ensued between ' 

 Profs. Foerster and Franz. ' 



Dr. Witt, of the Urania Observatory of Berlin, observed 

 that a simple glance at the stereoscopic views of the moon shows , 

 a considerable elongation. 



Dr. Marcuse, formerly delegate of the Geodetic Office of 

 Potsdam, in the Sandwich Islands, for the study of the vari- 

 ation of latitudes, called attention to the necessity of gener- 

 ally extending the methods of photographic registration of the 

 observations of latitudes, applying them in quite a general 

 manner to the geographical determinations obtained in travel- 

 ling. He considers, having had occasion from 1S93 to super- 

 intend the construction of a photographic zenithal telescope, • 

 and afterwards to use it, that the photographic registration of 

 the measures of altitudes and transits can be easily olMained 

 by means of a convenient ur»iversal instrument, adapted to 

 visual as well as photographic measuring ; and that with it» . 

 surety and precision are gained. An instrument for that 

 purpose is being constructed. 



Dr. Max Wolf, of Heidelberg, so well known for his photo- 

 graphic discoveries of small planets, spoke on the researches 

 made by him on an objective worked by Dr. Pauly in Jena, 

 with the aperture of 21 2 cm., and the focal distance of 

 445 cm. It is formed of the new glass of Jena, and must 

 possess better chromatic corrections than the old systems. In 

 fact, the investigation with the spectroscope has shown that the 

 colours are exactly comprised from the extreme red to the blue ; 

 only towards the G line the colours begin to deviate. A 

 comparison of the curve that represents the position of the 

 focal points corresponding to the various colours, with 

 analogous curves given by objectives of Fraunhofer, Grubb 

 and Clark, shows the superiority of the objective of Pauly to 

 the best anterior ones. While the deviation of the focus in the 

 middle of the blue scarcely reaches to 000003 "f '^e focal 

 distance, that of 000065, determined by Clark, is far the least 

 considerable of those remaining. The correction of sphericity 

 is also small. .Many delicate couples of stars are separated ; 

 e.g. T) Coronae (distance o"4), /»., liootis (0'"9), I Coionae 

 (o."4), \ Cassiopeiae (o "6), ^ Cygni (2-"9), { Hercules (0'"5), 

 o2 338 to''7), 2 2695 (o' '9). Arcturus in the angle of position 

 120" appears lengthened ; (," Bootis and 52 .\rietis could not be 

 resolved. The size of the stellar discs amounts to 0'"24 for the 

 sixth magnitude, to o' 15 for the eighth. Dr. Pauly added 

 some explanations on the manufacture of the new objective. 

 The first attempts to eliminate the secondary spectrum go back 

 to the year 1S86 ; but then the glass used was not suitable. Only 

 for two years has it become possible to obtain a new glass per- 

 fectly well adapted, the dispersive properties of which insure 

 absolute elimination of the secondary spectrum. The pictures 

 of the sun and moon are surprising, especially of the moon. 



Prof. Porro presented a paper by the new member of the 

 Association, Prof. \iio N'otterra, of iheTurinUniversity, on the 

 mechanical theory of the motions of the terrestrial pole. In this 

 paper are recapitulated the results of a more extended work, 

 which will be published in Ada Malhcmatiia. 



