404 



NA TURE 



February 2^, 1896 



and when opened, on September 6, it presented a gruesome 

 spectacle. The magnets were covered with rust, the wood-work 

 was swollen and would not fit the joints for which it was 

 intended, the wires in the eyepieces missing, silvered mirrors 

 spoilt, and other horrors which it can be imagined scientific 

 apparatus would present after such treatment. All the damages 

 had to be remedied on the spot by their own ingenuity, while, 

 to add to their distress, they lost by the upset much of their 

 petroleum, and had to reduce their light. Nevertheless, in the 

 early days of November, all repairs were effected and the 

 instruments ready for work. 



The results of the expedition are practically divided into 

 three parts. In the first, which is more especially under the 

 superintendence of M, V. Fuss, are given the description of 

 the method and the results of the observations at numerous 

 stations for the determination of geographical position. These 

 observations have not been made with that rigorous accuracy to 

 which, we are accustomed in inquiries that have for their aim the 

 discussion of the variations of latitude. They are rather field 

 observations, made with the sextant, and instruments possessing 

 similar accuracy, and are no doubt very useful in constructing 

 maps of a practically unknown country. In the same way with 

 the longitude determinations, there is no electrical communi- 

 cation between these places, of which Jakutsk is possibly the 

 only one that would be recognised by the ordinary English 

 reader., A few box chronometers were carried irom station to 

 station to determine the difference of local time. Moon cul- 

 minations and occultations were also employed, and, strange to 

 say, eclipses of Jupiter's satellites. Nothing is said about the 

 errors of the tables or the con-ections that have been applied to 

 remove those errors, but the results agree fairly well with other 

 methods. Possibly those observations only have been used, 

 which coincided with others made in a known longitude ; but 

 since the whole chain is made to depend for absolute longitude 

 on that of a station at Jakutsk, determined on the occasion of 

 the eighteenth century transits of \'enus, and now unrecognisable, 

 they do not probably interfere much with the final accuracy. 

 The outcome of the inquiry is to give us more or less trustworthy 

 positions of some twenty-four stations ranging between Sh.-gh. 

 east longitude from Greenwich, and from 60^-74°, north latitude. 



In the next section, under the superintendence of MM. N. 

 Jiirgens and F. Midler, are presented the results of the mag- 

 netical observations. M. Midler's part is more particularly 

 confined to deriving the elements of the earth's magnetism at a 

 considerable number of stations, all in North-East Siberia, by 

 a few observations of the declination, dip, and horizontal force 

 at each. M. Jiirgens took charge of the Ssagastyr station, 

 where, in greater detail, he sought not only the absolute force, 

 but the hourly variation of the magnetic elements. M. Miiller, 

 as his share, is able to present a table in which, for seventeen 

 stations, the three elements have been fairly well determined, 

 while in twenty-eight more or less complete observations have 

 been made. From November 1882 to June 1884, M. Jiirgens' 

 department made hourly observations of the declination, and 

 of the horizontal and vertical force, and on selected days 

 observations at every five minutes. The instruments appear to 

 have been critically examined, and the results of an inquiry 

 conducted so far away from beaten tracks possesses a special 

 interest. 



Advantage was taken of the peculiar position to make some 

 observations on the aurora as to its form, colour, direction, and 

 altitude. These will be found in what may be called the third 

 section, together with the history of the expedition written by 

 Dr. A. Bunge, wherein will be found many interesting remarks 

 on a country but little known. The climate, the native inhabi- 

 tants, the flora and fauna of the district, all come more or less 

 under his observant notice, and are treated easily and pleasantly. 



In the second work the element of adventure is, of course, 

 wanting, and, with greater ease. Dr. Palazzo has been able 

 to collect his data from various points on the Italian 

 Peninsula, in such a way as to present a tolerably com- 

 plete magnetic survey of the whole country. A chain of 

 stations has been selected, starting from Rome and proceeding 

 south-east past Naples towards Brindisi. Other positions have 

 been occupied on the Adriatic coast, including one in the 

 Tremiti Isles ; while another group occupies the north-east, and 

 includes Venice, Ravenna, and other well-known places. The 

 entire series includes twenty-two stations. Dr. Palazzo has 

 devoted great attention to the form of his instruments, and has 

 been alive to the importance of deriving the instrumental con- 

 stants with accuracy. His method of procedure is set out at 



NO. 1374, VOL. 53] 



length in the first part of his paper. In the second part, the 

 details of his observations are given. On the average, these do 

 not extend over more than two or three days at each station, 

 which have sufficed for the determination of the declination by 

 observing azimuths of the sun. The horizontal force has been 

 obtained by the method of counting the number of oscillations 

 made by the magnet in a given time. These in connection with 

 the dip, also derived at each of the stations, have permitted 

 him, in the usual method, to derive the vertical force and total 

 intensity. The whole operation and deductions are conveniently 

 exhibited in symmetrically arranged tables. 



THE MOVEMENTS OF THE TERRESTRIAL 



POLE DURING THE YEARS 1890-95. 

 "TOWARDS the latter end of last year Prof. Albrech gave a 

 preliminary account of the, then, known movements of the 

 terrestrial pole at the eleventh general conference of the 

 " International Erdmessung." Since that date he has made a 

 more definite investigation, the results of which will be pub- 

 lished in the Verhandliingen der Berliner Conferenz ; but as this 

 will not just yet appear, he gives in the current number of the 

 Astr. Nach. (No. 3333) a brief summary of the results. 



The observations have been made at several observatories, 

 namely, Kasan, Pulkowa, Prag, Berlin, Bamberg, Kiel, Karls- 

 ruhe, Strassburg, New York (Columbia College), and Bethlehem, 

 also at the Military Geographical Institute in Vienna, the 



Curve showing tiie relation between the mean and apparent positions of the 

 pole during the years 1890-95. 



Geodetic Institute in Potsdam, and at the American Coast and 

 Geodetic Survey. 



Prof. Albrech has not, however, used all the observations in 

 the discussion, but enough " um den Versuch einer Ableitung 

 der Bahn des Pols fiir den ganzen fiinfjiihrigen Zeitraum mit 

 Aussicht auf Erfolg durchfiihren zu konnen." 



The method of computation adopted was somewhat analogous 

 to that employed by Kostinsky in 1893. Commencing with the 

 monthly observed mean from each station, the deviations 

 ((^ - </)„) of the instantaneous pole elevations from a very 

 accurate mean value were graphically formed for every tenth 

 part of the year ; a system of coordinates was also arranged in 

 which the positive-axis of x pointed towards Greenwich, that of 

 y 90° to the westward, the origin coinciding with the mean 

 position of the pole. 



In this way Prof. Albrech obtained a series of points, which, 

 when plotted out and connected together by means of a curve, 

 would show the relation of the position of the terrestrial pole, 

 at any moment during the interval covered by the observations, 

 to its mean position. 



The accompanying curve is a reproduction of that given by 

 Prof. Albrech. 



