5 66 



NA TURE 



[Oct. ii, 18S3 



Prof. Weiss, were received with much approval. Dr. 

 Elkin reported parallax determinations of southern stars 

 executed by him and Gill at the Cape, especially that 

 of a Centauri, which might be fixed at about 75 sec, and 

 that of Sirius, which increased to '4 sec. 



Pickering drew attention to photometric investigations 

 carried out at the observatory of Harvard College. 

 Janssen (Meudon) spoke on the observations which had 

 been made in connection with the sun's eclipse of May 6 

 this year, discussed the photographs of the corona they 

 had taken, and referred to the efforts made by l'alisa 

 with a view to discovering an intra-Mercurial planet, 

 efforts which, as was well known, had yielded a ne 

 result. Prof. Foerster gave an interesting accu 

 observations made in the Berlin Observatory, by whii h 

 he endeavoured to prove that the one ground-pillar of the 

 Berlin Observatory on which investigations had hitherto 

 been conducted had for the last twenty-five years been 

 subjected to angular movements which were com 

 with the eleven years' period of solar spots. The 

 annual averages of inclinations of the pillar from 1856 to 

 1881 adhered as closely to Wolf's relative numbers as 

 did the annual averages of the magnetic declination. 

 From these facts Prof. Foerster drew the conclusion that 

 very considerable effects could be traced from the radi- 

 cal changes of the eleven years' solar period. In connec- 

 tion with this communication of Foerster's, B. A. Gould 

 reported how he had made quite similar observations on 

 the sea coast. Prof. Oppolzer (Vienna) spoke of investi- 

 gations he had made in the Vienna Observatory with a 

 view to determining the length of the seconds pendulum 

 and the influence of the simultaneous oscillations of the 

 stand. Foli gave an account of his examinations into 

 the daily nutation and precession of the earth and his 

 new tables of precession, and communicated some 

 information regarding the observatory of Lie"ge. Pechule 

 .Copenhagen) sought to refute Stone's assertion that 

 there was a difference of 1^ sec. between the former and 

 the present Julian year, an assertion which had already 

 been declared by Airy to be incorrect. He pointed out 

 where Stone had committed an error in his calculations, 

 and brought forward proof to show that the difference 

 amounted to but four seconds every thousand years. 

 Oudemans (Utrecht) corrected an assertion of Stone's 

 that there was an error of 28 sec. in the reduction from 

 median to sidereal time. Steinheil (Munich) referred to 

 new constructions of telescopes calculated by him, and to 

 the influence of the prism in the case of refracting 

 telescopes on the sharpness of the image, in respect 

 of the achromatism of the images, and to the means 

 by which he counteracted the prejudicial effects in such 

 cases. 



Cm Sept. 15 the members of the Congress visited the Ob- 

 servatory. The astronomers were highly satisfied with the 

 arrangement of the observatory and the system of apparatus. 

 The 27-inch instrument, supplied by Grubb of Dublin, 

 and described in NATURE shortly after its completion, 

 was an especial object of interest. Unfortunately the 

 sky was clouded, so that it was impossible for the astro- 

 nomers to carry out the observations they had intended 

 with this powerful instrument. In reference to ad- 

 ministrative matters we have also to mention Foerster's 

 report on the conclusions of the International Commission 

 respecting Kiel as an international centre, particularly in 

 regard to the contributions of the respective astronomical 

 institutes. On September 16 a social excursion was made 

 to the neighbouring Kahlenberg, and this event was also 

 made the occasion of the baptism of several newly dis- 

 covered planets; the planet 234, discovered by Peters, 

 receiving the name of Barbara ; the three discovered by 

 Palisa (Vienna) being called (229) Adelinda, (231) Vindo- 

 bona, (225) Henrietta. It was resolved that the next 

 meeting of the Society should be held at Geneva in 

 1885. 



THE NORWEGIAN CIRCUMPOLAR STATION 



T T is with pleasure that I resp&nd to the invitation of 

 *■ NATURE to give an account of our labours here 

 during the last twelve months, and I may, in doing so, 

 state that I have purposely delayed writing these lines, in 

 order to be able to give the result of our researches during 

 a whole year. 



The Norwegian Government have contributed their 

 share to the international research of the physical con- 

 ditions of the Polar regions by the establishment of the 

 observatory here at Bossekop in Alten (I'inmarken). The 

 station, which is situated at the bottom of the Alten 

 Fjord in 69° 58' lat. and 23 15' long., commenced its 

 labours on August 1, 18S2, which are to be continued 

 until September 1, 18S3, in accordance with the pro- 

 gramme of the Polar Congress held in St. Petersburg in 

 1 88 1. The equipment and instruments of the station, as 

 well as its whole organisation, are also in accordance with 

 the principles formulated by the Polar Congresses held 

 in Hamburg in 1879, in Bern in 1880, and in St. Peters- 

 1 1 83 1. The personnel of the station consists of 

 the writer as chief, Doctors C. Krafft, sub-chief, J. Schroeter 

 and F. Hesselberg, observers, and Herr O. Hagen, instru- 

 ment maker and caretaker. 



The obligatory observations embrace astronomical 

 observations, readings every hour of the meteorological 

 and magnetic variations, absolute measurements of the 

 terrestrial current's three components, and studies of the 

 aurora borealis. For the hourly observations the day 

 and night have been divided into four watches of six 

 hours each, which are taken by each one in turn. 



In order to effect the astronomical observations, i.e. the 

 determination of time and place, a small observatory 25 m. 

 in length, breadth, and height has been erected of deals, 

 the roof and the southern and northern walls of which are 

 provided with shutters to be opened during meridian obser- 

 vations. On a fixed pillar in the centre is placed a 

 universal instrument by Repsold, besides which we 

 possess three box chronometers by FrocUham, KesseU, 

 and Mewes, the last named being regulated by star time, 

 as well as two pocket chronometers by Kessels and 

 Brocking. 



The weather during the winter and certain other cir- 

 cumstances have to some extent affected the astronomical 

 observations, so that for the determination of time only 

 a few meridian passages have been observed ; but this 

 circumstance is of no consequence whatever, as the station 

 is independent of local determination of the time for 

 ascertaining the absolute time, viz. the common mean time 

 of Gottingen, which has been adopted at all the Polar 

 stations as the common time, and which we receive from 

 the observatory at Christiania through the telegraph 

 office, about ten minutes distant, twice a week, at 9 a.m. 

 on Sundays and 8 a.m. on Wednesdays, Greenwich time. 



We have, however, a few meridian passages and obser- 

 vations of time with corresponding sun altitudes, which 

 may be used for the verification of the longitude of the 

 place. The Polar altitude has been verified by the 

 measuring of circummeridian altitudes of the sun and 

 Polaris. The universal instrument has also been em- 

 ployed for the determination of azimuth for the observa- 

 tions of the aurora borealis and the magnetic declination. 

 Of magnetical instruments we have a set for the deter- 

 mination of the elements of the terrestrial current, viz. 

 a unifilar magnetometer by Elliott Brothers of London, 

 and a Dover inclinatorium, both verified at Kew. The 

 variation instruments, which are constructed on Lamont's 

 principle by Prof. Mohn, and executed by Herr C. Olsen, 

 optician, of Christiania, consist of a variation instru- 

 ment, a unifilar apparatus with two fixed deflectors for 

 the observation of the variations of the horizontal inten- 

 sity, and a unifilar apparatus with vertical bars of soft 

 iron as deflectors, whose magnetic moment varies accord- 



