CO «' CM o uJ * . * . * . * . * .4 it.*.*.*.*.*.*.*. .*.*.*.*.*.*.*.* * - * . * ; . .* . * . * . * *** TT_T^.tD./ LIBRARY UNIVERSITY OF CALIFORNIA. * A •. * . . *•*•*•*•*•*•* * • * • t • • • *.*.* *.*.*•*•*•*•* If. * Tlf. • it?. •• •%. • •% « -ty • If. * . * *<* * j * -*;4i •* * : * . * . * . 4t • 4c>4c*4c*4(*! * * •* •* t • 41 * 41 * : :A «A« _ 'atp' _ i * «K * <(«'•. * i 4t • A * 4^ \ • if. '••%.- \ 4^ • 4s • 4^ * •* •* •* ' * ^ *• '3^ « ^r • • i * JK H #^>. ' JK * 4 • t • itr 9 jK • IB * • 3©v '' * : .41 •: + .* "* -,*, •*•'*' * 'it '*' 'i • i *"• *.*.*.* * . * . * . % . * *.*.*.*.*.*•*•*'*•*.*•*•*•* > . * * . * . * . * . * 41 • 41 c:4»> 41 4( THE NORWEGIAN NOETH POLAE EXPEDITION 1893—1896 SCIENTIFIC RESULTS VOLUME II THE NORWEGIAN NORTH POLAR EXPEDITION 1893—1896 SCIENTIFIC EESULTS EDITED BY FEIDTJOF NANSEN VOLUME II or THE UNIVERSITY OF PUBLISHED BY THE FRIDTJOF NANSEN FUND FOR THE ADVANCEMENT OF SCIENCE LONDON, CHRISTIANIA NEW YORK, BOMBAY LEIPZIG JACOB DYBWAD LONGMANS, GREEN, AND CO. F' A" BROCKHAUS 1901 PRINTED BY A. W. BR0GGER. CHRISTIANIA, 1901, CONTENTS OF VOL. II. VI. H. GEELMUYDEN. Astronomical Observations. Pp. 1 — 136, with two Charts. (Received August 1899— August 1900.) VII. AKSEL S. STEEN. Terrestrial Magnetism. Pp. 1—196, with 17 Plates. (Received May — December 1900.) VIII. 0. E. SCHIOTZ. Results of the Pendulum Observations and some Remarks on the Constitution of the Earth's Crust. Pp. 1—90. (Received July 1900.) PEEFACE TO VOL. II. _Lhe astronomical, magnetic, and pendulum observations affording the material for the three important Memoirs contained in this volume, were nearly all of them, with the exception of the observations from the sledge-journey, made by Capt. SIGURD SCOTT-HANSEN. In my preface to Vol. I of this Report, I have gratefully acknowledged his important share in the results of the expedition. The present volume containing some part of his work, will testify to the astonishing quantity of multifarious observations he has been able to accomplish, and to the intelligent care and accuracy with which he made them, notwithstanding the often trying circumstances. Memoir VI, containing the Astronomical Observations made during the expedition, and their Results, has been prepared by Prof. H. GEELMUYDEN. Before our start, Prof. GEELMUYDEN gave the expedition his important assistance by aiding in our equipment with astronomical instruments and chronometers, and giving us instruction in the best methods of making observations for determining our position in high latitudes. After our return, he had the great kindness to undertake the troublesome and slow work of arranging and supervising the computation of our numerous observations, and preparing the report for the press. He has also constructed and drawn the two valuable charts accompanying this volume, of the Fram's route and II the sledge-journey, in which he has set forth the results of his work that has been of such importance to the expedition. These charts give highly interesting information of the drift of the ice during the several seasons of the year. The relation of this drift to winds and currents will be discussed in a later Memoir on the Oceanography, which will shortly appear in Vol. HI. Memoir VII, on Terrestrial Magnetism, has been prepared by Mr. AKSEL S. STEEN, Sub-director of the Meteorological Institute of Christiania, and contains SCOTT-HANSEN'S Magnetic Observations and their results. As mentioned by Mr. STEEN, Prof. G. NEUMAYER gave the expedition his valuable assistance by taking charge of our magnetic equipment. He had the instruments made according to his orders, and partly according to his special design; and he also gave Capt. SCOTT-HANSEN careful instruction in the use of the instruments, and in the methods of making observations. I hope it may give him some satisfaction to see how well his instruction has been utilized, and to see the important results of SCOTT-HANSEN'S observations, which have been so ably and carefully worked up by Mr. AKSEL S. STEEN. Prof. AD. SCHMIDT of Gotha has much increased the scien- tific interest of these results by kindly calculating theoretically the values of the magnetic elements for all localities where magnetic observations were made during the expedition. Memoir VIII, on the Results of SCOTT-HANSEN'S Pendulum Observations, has been prepared by Prof. 0. E. SCHIST z, who has also added some interesting conclusions with regard to the constitution of the earth's crust, which he thinks may be drawn from these observations. When I planned the expedition, I considered it not impossible that we might meet with unknown land in high latitudes; and as in such a case it would be of great importance to be able to take pendulum observations, Prof. 0. E. SCHIOTZ kindly undertook to equip us for this purpose. It was decided to order a pendulum apparatus of Colonel VON STERNECK'S pattern from Vienna, and VON STERNECK himself had the great kindness to determine the constants Ill of the two pendulums. We met with no land in the North Polar Basin, and thus the ordinary conditions for making pendulum observations did not exist. But SCOTT-HANSEN thought that the strong ship frozen firmly into the drifting ice, or the ice itself, might possibly afford a sufficiently solid base for the pendulum apparatus, and decided to make some observations as an experiment. Thus the first series of pendulum observations, which, to my knowledge, have ever been made over the sea, were made over the deep North Polar Basin. We had some doubt as to the value of the observations taken under such extraordinary circumstances; but thanks to Prof. SCHIOTZ'S able elaboration and discussion of the material, it now appears that these observations afford perhaps some of the most important results of the expedition. I desire here to convey my hearty thanks to the contributors to this volume, and to Prof. G. NEUMAYER, Prof. AD. SCHMIDT, and Colonel VON STERNECK, for their valuable assistance and contributions. GODTHAB, LYSAKER. January, 1901. FRIDTJOF NANSEN. VI. ASTRONOMICAL OBSERVATIONS ARRANGED AND REDUCED UNDER THE SUPERVISION OF H. GEELMUYDEN, PROFESSOR OF ASTRONOMY AT THE UNIVERSITY OF CHRISTIAN!*. WITH TWO CHARTS. TABLE OF CONTENTS. Introduction: Page Astronomical and Nautical Instruments VII Determination of Latitude and Local Time XI Determination of Azimuth XVII Longitude, and Rate of Chronometers XIX Voyage along the Coast of Siberia LIV The Sledge-Expedition LVII The two Charts LX Observations: A. Altitudes measured with the Altazimuths 3 B. Observations with the Sextant 26 Observations and Results: C. Determination of Azimuth 61 D. Determination of Magnetic Declination by Compass 70 E. Determination of Declination and Deviation by Compass on Board 77 F. Direct Determination of Deviation 82 Results: G. Greenwich Time 85 H. Latitude, Local Time, and Longitude 86 I. Refraction 108 The Sledge-Expedition: Observations 1895 HI Observations taken at the Winter Hut 125 On the way southwards from the Winter Hut 130 ADDITIONS AND CORRECTIONS. Page 4. The following observations were taken ashore at Khabarova: 1893 Oc. Watch Vertical Circle Level Watch Hw-W h in s O 1 It 1 H h m m s Aug. 1 Sun L. L. W 22 4 29 306 36 8.5 36 27 N1.2 S9.7 23 45 - 5 46.7 July 29 Terr. Mark s — 270 18 28 17 59 _ 23 52 - 6 2.7 Aug. 2 ** N — 89 41 32 41 12.5 — Page The watch was in this case the chronometer Iversen. — Cloudy. 7. For Remarks 8) and 9) read: Assumed star S Persei and + 10' to circle Oc. N. 8. July 5. Assumed U. L. for L. L. 17. Remark 4). For the read be. 24. The following observations are to be inserted: 1896 May 8 31. 32. 47. 64. 65. 74. 77. 88. 107. 117. 119. Sun [U. L.] Oc. Watch Vertical Circle Level h m s o * n I It S 19 10 44 289 53 45 53 5.5 E 10.8 W 16.4 N 17 5 69 57 11 56 26.5 E 13.1 W 13.3 26. Among the days of determination of Index error is to be inserted: 30. September 28. Remark: Ass. corr. + 10' to the fourth altitude. The following observations are to be inserted: 1894 May 20. 1893 Hor. Watch Sextant Watch Hw-W h m s 0 / U h m m s Nov. 22 a Cygni Jupiter L. L. Merc. n 21 28 53.5 21 47 48 109 54 35 42 14 45 19 36 23 47 + 7 4.3 + 7 6.3 March 30. Hw-W for lm 39s.2 read lm 39".7. April 23. Sextant for 2° 12' read 3° 12'. May 23. Col. Remarks, cancel [Omitted], April 25. Col. A, for 268° 5' 11" read 268° 28' 45". August 2. Last observation of C, for 182° read 181°. November 1. Magn. Decl. for 27°.4 read 26°.65. Line 5 from bottom, for must read had to. October 2. M. T.-Hw for 44s read 46" ; N. Lat. for 78° 52'.2 read 78° 51. '8. Aug. 8. N. Lat. for 80° 55. '0 read 81° 5/0. April 26, last observation, LT — I, for 43s read 53" (gives the E. Long. 1 ' greater). June 4, third line, for some read same. INTRODUCTION. Astronomical and Nautical Instruments. The following is an enumeration and brief description of the instruments used for astronomical observations. Altazimuth by C. H. G. OLSEN in Christiania. The horizontal and vertical circles, of 21 cm. diameter, are graduated on platinum to 10' and read off by two microscopes placed diametrically reading to 10", the single seconds being easily estimated. The microscopes for the horizontal circle follow the instrument in the motion about the vertical axis, the horizontal circle being fixed, while the vertical circle follows the telescope in the motion about the horizontal axis, the corresponding microscopes being fixed at the ends of the horizontal diameter. The alidade bearing these microscopes is provided with a fixed level, adjustable by screw and spring working on an arm going downwards from the centre. Both circles being graduated from left to right, as seen from the centre, the correction to the reading of the vertical circle is positive when the right end of the level is the higher. The level is divided from the middle and the angular value of a part was given by the maker as 4", which was found to be sufficiently accurate; consequently the difference between the readings of the two ends of the bubble, multiplied by 2, gives the correction to the circle-reading in seconds. The degrees and tens of minutes are for both circles read off by an index, which is, for the vertical circle, placed at the top. The microscopes of both circles were always pointed to two adjacent division lines, one on each side of the central notch marking the zero of single minutes in the field of the microscope. Generally the two readings did not differ by more than the accidental error of pointing, a few seconds; VIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. during the last year (from the autumn of 1895) the right microscope for the vertical circle seems, however, to have got somewhat out of adjustment, the difference between the two readings being generally about 20" and in some cases reaching 30". As there are not sufficient data to take this difference into due consideration it has been necessary to take the simple mean in all cases. When it happened that a division-line was near the middle of the field of the microscope, the observer often pointed the micrometer wires to a line on each side, and the mean of the three was then taken. The telescope has an aperture of about 5 cm. and 42 cm. focal length. It was provided with two eyepieces giving magnifying powers of about 30 and 40. The optical axis is broken by a reflecting prism and the eyepiece placed at one end of the horizontal axis. The illumination of the field comes from a lamp at the other end of the axis. The wires in the focus are fine lines engraved on glass. There was a set of 13 wires (vertical in the hori- zontal position of the telescope) but only the middle wire and the horizontal wire were used for the observations. The striding level of the horizontal axis is divided from the middle; one division = 4". As this level must always be read off in the two opposite positions, the sum of the two differences will give the inclination of the axis in seconds. 1896, May 6, it was noticed by Capt. SVERDRUP that the motion of the telescope about the horizontal axis was not quite independent of that of the alidade; when the screw working on the arm of the latter was turned (in order to get the bubble of the level in a convenient position) it had an effect of some seconds on the pointing of the telescope. Lieutenant SCOTT-HANSEN took the instrument on board, loosened the parts and cleaned them, but the error was still perceptible in some positions of the instrument. It is of course only when the screw is touched between the pointing of the star and the reading of the microscopes and level, that this can introduce an error in the observation, but Mr. SCOTT-HANSEN is of opinion that such an error may occur in some of the observations from the winter 1895 — 96. Before the cleaning of the instrument he made some experiments in order to ascertain the amount, and found the maximum effect to be about 50". This instrument is at present on board the From on Capt. SVERDRUP'S expedition to Greenland. NO. 6.] INTRODUCTION. INSTRUMENTS. IX A small altazimuth by Olsen. The circles have diameters of 10 cm. and are graduated to half degrees, two opposite verniers giving the single minutes. The relative movement of circles and reading-apparatus is the same as in the larger instrument. A fixed level, placed parallel to the vertical circle, was read off on measuring altitudes, but its position was not such that it can be considered as an alidade-level. It is divided from the middle in parts of 0'.8. The telescope, whose axis is broken by a reflecting prism, has an aperture of 2 cm, a focal length of 16 cm., and a magnifying power of 12. The wires in the focus consist of one horizontal and two vertical lines (about 4' apart) engraved on glass. This instrument was not much used on board but followed Mr. Nansen on his sledge expedition. A sextant by Hechelmann, of the usual construction, giving the angles to 10". Usually the altitudes were measured from the ice as a natural horizon or over a basin of mercury as an artificial horizon. On some few occasions a glass horizon by Negretti & Zambra was used; the level which was read off in its two positions, when placed in the vertical plane of the celestial object, was divided to 2'.6. There was also another glass horizon with aluminium mounting, by Porter, which was only used 1893 September 28 and October 2; its level was divided to 3'.9. Occasionally a trough of tar or a pool of water on the ice was used as an artificial horizon. The astronomical telescope was almost invariably used. A small pocket sextant by Gary, London, was used by Mr. Nansen on his sledge expedition. The limb, of radius 4.5 cm., is divided to half degrees, the vernier giving single minutes. The instrument is made of aluminium which did not, however, prove to be a good metal for this purpose, the screws becoming immoveable from oxidation. Several compasses, among them an azimuth-compass by Hechelmann with 8 small needles suspended by silk wires. The card, divided to degrees, has a diameter of 21 cm. The reading of the card was always made both ways, the eye being held in the plane through the vertical and the horizontal wire of the diopter-apparatus, either before the thread or before the slit. 2 X GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. This compass was often used on the ice at a convenient distance from the ship. It was provided with a mirror, placed before the wire-vane of the sight, and moveable about a horizontal axis. Besides the steering compass, which was placed before the wheel, behind the mizzen mast, and which could be provided with sights, there was an azimuth dial on the bridge, suspended in gimbals; diameter 15.5 cm., distance between the sights 12.5 cm. This was often used to take the bearing of the Sun or a star in order to determine the combined magnetic declination and deviation on board. Two small compasses by Olsen with sharp needles pointing to the rim which was divided into degrees. The suspension is by agate cups on steel pins. The one is mounted in a brass box and has a needle of 64 mm. length, the other an aluminium box and needle of 59 mm. length. Both were used by Mr. Nansen on the sledge-expedition, and on some few occasions by Mr. Scott-Hansen before Nansen's departure. A telescope by Negretti and Zambra, with an aperture of 7.4 cm., the astronomical eyepiece giving a power of 65. The principal use of this instrument was the observation of eclipses of Jupiter's Satellites. A smaller telescope of aluminium was used by Mr. Nansen on the sledge-expedition. The chronometers and their installation will be mentioned in another paragraph. Lieut. Scott-Hansen, who has made by far the most of the observations, has expressed a desire to acknowledge, on this occasion, the good services of his assistants, Mr. JOHANSEN and Mr. NORDAHL, the latter after Johansen's departure with Nansen on the sledge-expedition. NO. 6.] INTRODUCTION. LATITUDE AND LOCAL TIME. XI Determination of Latitude and Local Time. Latitude and local time were always determined by observation of alti- tudes. The altazimuths, especially the larger instrument, were almost inva- riably used for stars, in many cases also for the sun. They were then mounted near the ship on an ice pillar, surmounted by a slab of slate. After levelling, the time of pointing on the star was noted by a watch (generally compared before and after with the standard chronometer) and then the vertical circle and its level read off. With few exceptions every star was observed in the two positions of the instrument, with the object glass to the right and to the left of the observer placed at the end of the horizontal axis. The general rule was to determine the latitude and local time simultaneously by taking two stars in azimuths differing about 90°. As the zenith point for the vertical circle of the large altazimuth never differed more than some seconds from 0°, the circle-reading for a point above the horizon was either between 0° and 90°, when the object glass was to the left of the observer, or between 270° and 360°, when it was to the right. For the sake of brevity these two cases shall be distinguished by the notation "small numbers" and "great numbers". Supposing the zenith point to be exactly 0° O7 0", the apparent altitude will be Circle-reading — 270° 0' 0" for great numbers and 90° 0' 0" — Circle-reading for small numbers, when the circle-reading includes the correction for level in the sense right — left. When the zenith point differs from 0° 0' 0", the numbers 90° 0' 0" and 270° 0' 0" are subject to the same change. For the reduction to true altitude BESSEL'S refraction was used, as given in ALBRECHT'S "Formeln und Hillfstafeln fur geographische Ortsbestimmungen", with an extension of the temperature table down to — 50° C., calculated by Bessel's formula. On taking the mean of the two altitudes of the same star, as shown above, the result is free from any error in the assumed zenith point; but as the mean of the altitudes does not always correspond, with sufficient accuracy, to the mean of clock-times, it is necessary to apply a correction on this account, when the observations are treated in this manner. XII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. When one star was taken near the meridian, the other near the prime vertical, which was frequently the case, the first could be used for the latitude, the other for the clock error. In some cases the reduction was accordingly made in this manner. But as the calculation of one of these quantities requires the knowledge of the other, and the drift of the ship from the time of the last observation was unknown, it was always necessary to apply corrections afterwards by a differential formula. For the great mass of these observations of two stars it was therefore preferred to deduce the definitive latitude and clock error at once by means of the two given alti- tudes and declinations, the difference of right ascensions and the difference of clock times, reduced to sidereal time. It will not be necessary to repro- duce here the formulae used, the method being well known. As a control on the computation as well as on the observations, the computation was generally carried out in duplicate, the two altitudes taken in the same position of the instrument (both with "great numbers" or both with "small numbers") being combined together. Both results are then affected by a possible error of the assumed zenith point, but in contrary directions, so that in the mean of the two the error will be very nearly eliminated, as may be seen from the following differential formulee, where h and h' are the altitudes of the two stars taken in the same position of the instrument, a and a' the corres- ponding azimuths, q> the latitude and 9 the clock correction (i. e. local time minus clock time): sin a . dh' — sin a' . dh de = sin (a' — a) cos a' dh — cos a sin (a' — a) cos ^ When the altitudes are subject to no other errors than that of the assumed zenith point, dh = dh' for the one position of the instrument and likewise for the other, but then with opposite sign; and as the coefficients depending on the azimuths are nearly the same in both combinations, the errors of the two results are nearly equal and opposite. The same formulae may of course also serve to compute the correction to the zenith point when required. If one of the altitudes, or both, are the means of a series, and the mean of the clock times (T or T) requires a sensible correction in order to corres- NO. 6.] INTRODUCTION. LATITUDE AND LOCAL TIME. XIII pond to the mean of altitudes, the corrections to the latitude and hour angle, as computed by the original numbers, will be: At = — si" a sin «' cos sin (a' — a) sin a cos a sin (a' — a) ' — T) and d<9 = dl — AT. It happened sometimes that one star was observed in both positions of the instrument, but the other only in one. In order to utilise the latter it was necessary to deduce the zenith point from the first. If x is the correction to the assumed zenith point, hl and fe2 the two altitudes of the same star, as following from this assumption, tl and t2 the corresponding hour angles (suffix 1 and 2 corresponding to small and great numbers) d the declination, the following exact formula cos — •sin(^i-2-^+a5) = , • cos ( cosd sin . sin 2 "\2 may be safely replaced by h« — h, hn -4- h, . t, -f- << ^o — ^i -J- -J- "«s gf> cos a sec — — i — I sm 2 i ' . — -^ — * , cos 2 2 where t is the centrigrade temperature; consequently two values k and k* corresponding to the temperatures t and t' are connected by the equation k _ 273 + f The tables in use among our sailors, which are adapted to a certain curvature Q' and a certain mean temperature t', give D = 600" for a height of 100 feet (norw.) = 31.37 metres; consequently k' may be deduced from the equation 600 = 8 1 (1 V). Supposing Q' to give the average curvature for latitude 50° (log Q' = 6.8049), this equation gives V = 0.139, and supposing further this value to be adapted to a temperature f = 10° C., the value corresponding to t = — 20°, which may be taken as a mean tem- perature in the polar regions, is k = fc/ = °-156 • Taking finally the curvature for 80° of latitude (log Q = 6.8060) the expression for the normal dip of the horizon in the polar regions will be D = 106".0 |/ height in metres, from which a table was formed. Casual irregularities may of course con- siderably surpass the difference between this and the mean value for tempe- rate regions. Observations of the midnight Sun in 1894, as compared with southern altitudes taken over an artificial horizon, seem to indicate a smaller value of the dip. During the voyage along the coast of Siberia the Sun's altitude was sometimes measured from a coast line at a given or estimated distance. Supposing the depression of this coast line, as seen from the height H, to be the sum of the dip for an eye's height H' having the coast line in the apparent horizon, and the angle between the two straight lines, issuing from XVI GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. the points in heights H and H' to the point in question, the expression will be C H , * where y is the given distance in miles (or minutes of arc) and C is the number of minutes in an arc of circle equal to the radius (3438). Using the above values of k and Q and multiplying by 60, this gives x = 110".8 - + 25".3 y when H is expressed in metres. On taking the altitude of a star with an artificial horizon it happened twice that one star was combined with the reflected image of another nearly in the same vertical (a and y Cygni, Castor and Pollux). These observations were utilised in the following manner. As soon as it was detected which stars had been observed, a preliminary calculation would give with sufficient accuracy their difference of azimuth. If H and h are the true altitudes of the two stars, D and d their declinations, R and r their right ascensions, A and a their azimuths, and P the measured angle diminished by a quantity corresponding to the sum of refractions, which could be found by the same preliminary calculation, the true altitudes are given by the following equations: A _ a cos (H + h) = cos P + 2cos H cos h sin2 — ~- TT I. TJ -J D __^_ y. ,4 fj sin2 — g — = sin2 — ~ (- cos D cos d sin2 — 5 cos H cos ft sin2 — ^— where approximate values of H and ft will suffice on the right. The determinations of time and latitude near the observations of Lunar Distances and of Solar Eclipses, the observations taken at sea in 1893 and on the sledge expedition, and some few others, have been computed by the writer, all the others by Mr. A. ALEXANDER, teacher of mathematics at the Royal Military Academy, and Mr. A. GRAARUD, assistant at the Norwegian Meteorological Institute, both in Christiania. The present volume contains all that is necessary for the reduction, except the meteorological data. An approximate value of the temperature NO. 6.] INTRODUCTION. AZIMUTH. XVII may be inferred from the length of the level-bubble for the vertical circle of the large altazimuth (List A of Observations) the length being about 20 for 0° and about 38 for —50° C. Determination of Azimuth. The astronomical foundation for the determination of magnetic declination was furnished either by the altazimuth or by an azimuth-compass, or in some cases by a magnetic theodolite. In the first case the telescope was first pointed to the magnetic observa- tory (either a centered mark or the objective of the magnetic theodolite, illu- minated from behind) and the horizontal circle read off on both microscopes ; then to the Sun or a star (either one of the stars whose altitudes were meas- ured for time and latitude, or, more frequently, a lower one) and the hori- zontal circle and striding level read off after the noting of the time. Some- times the observations were repeated in the other position of the instrument. If Cr and Ci are the circle readings for a terrestrial mark in or near the horizon, respectively with obj. right and obj. left, and the error of collimation (c) is defined by the condition that the objective end of the optical axis forms the angle 90° -}- c with the ocular end of the instrument's horizontal axis, then C = * (Or -C,) of course neglecting the difference of 180°. If R and L are the readings of the right and left end of the striding level, as seen by an observer facing the same way as the object glass, and if further the inclination of the axis is defined as positive when the right end is the higher, then p being the value of a division of the level. As remarked before, the sum of the two differences R — L, corresponding to the two positions of the level, will for this instrument give the inclination in seconds of arc. 3 XVIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. (NORW. POL. EXP. If a be the azimuth of the star at the moment of observation, reckoned from south through west, as computed from the given declination, latitude and clock error, A = 180° + a + i tg h ± c sec h will be the azimuth, from north through east, corresponding to the circle rea- ding 5 for the star; here h is the apparent altitude of the star, the double sign of c corresponding to obj. right and obj. left. It has not been necessary to take account of the collimation. For the high stars the effect is eliminated in the mean, as the observations were taken in both positions of the instrument and the altitudes were nearly the same on both occasions. This is, however, not visible from the circle-readings, which ought to differ by about 180°, but do not do so, the observer having always added 180° to the second circle-reading. When the small altazimuth was used the difference of 180° has been retained. For some low stars, observed only in one position of the instrument, the effect of collimation will be very nearly the same as for the terrestrial mark, supposing both to have been observed in the same position of the objective relative to the observer, which has not always been expressly stated. The accuracy of angle-measuring with the magnetic theodolite being infe- rior to that of the large altazimuth, a few seconds of arc are of no impor- tance in the determination of azimuth. The values of the angle C — S-\-A, where C is the circle-reading for the mark in the magnetic observatory, were transmitted to Mr. STEEN for applica- tion in the reduction of the observations of declination. On several occasions the Sun was observed directly with the magnetic theodolite. Lieut. SCOTT-HANSEN also made a great number of independent determi- nations of the magnetic declination by means of the azimuth compass, which was for this purpose mounted on the ice at a distance of at least 60 paces from the ship. The observations then consisted in simply noting the time when the Sun or a star passed the plane of the sights, and reading off the card of the compass. The reduction of these observations does not call for any further remark. Most of the azimuth-observations have been computed by Mr. ALEXANDER and Mr. GRAARUD. NO. 6.] INTRODUCTION. CHRONOMETERS. XIX Longitude, and Rate of Chronometers. The expedition was equipped with 3 Mean Time chronometers : Kutter 24, belonging to the ship, Hohwu 639 lent by the University Observatory in Christiania, and Iversen 961, lent by the maker, Mr. Iversen in Bergen. A fourth box chronometer, Frodsham 3555, lent by the Norwegian Meteorologi- cal Institute, was regulated to Sidereal Time some time before the departure and began with a small losing rate, which, however, continually increased during the first winter, and reached the inconveniently large value of between 5 and 7 seconds a day. It was not used for the observations of stars but only for some magnetical observations, and served for the daily comparisons by coincidences. These four chronometers will be designated in what follows by Kt, Hw, Iv and Fr respectively. There were also on board a number of pocket chronometers and watches, one of which was always used for the astronomical observations and com- pared with Hw, generally before and after each observation. The observation watch was also compared daily with Hw at the time of comparison for the box chronometers. The box chronometers were placed on two shelves in Lieut. SCOTT-HAN- SEN'S cabin, Htv and Fr only 16 cm., Kt and Iv 60 cm. above the deck. A thermometer which was placed in the lower shelf with the bulb 17 cm. above the deck, was read off at the time of the daily comparisons. In the same cabin was also a thermograph, 80 cm. above the deck, which was working almost continuously from 1893 July 5 to 1896 August 10. The thermograph was compared daily with a thermometer placed by its side and with the thermo- meter in the lower chronometer shelf. By means of this last comparison and the daily reading of the thermometer in the shelf, which can be compared with the thermograph-sheets for the same time, the mean temperature of the two lower chronometers can be determined with sufficient accuracy. Between the last Time Signal from the Christiania Observatory received at Vardo 1893 July 19 and the first after the return, received at Tromso 1896 August 23, a good many observations were taken which can be used XX GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. to determine the Greenwich Time. It was necessary to utilise them all, not only for the sake of longitude, but also to get a sufficiently accurate deter- mination of the rate of the chronometers which were used for the pendulum observations with the Sterneck-apparatus. The ordinary determinations of local time are quite useless for this purpose, because the ship was continually drif- ting and even a small drift east or west will have a considerable influence on the Local Time in these high latitudes. The observations for the determination of Greenwich Time were, however, very different in point of accuracy. They shall now be considered. Solar Eclipses. 1894 April 5 (April 6 on board). The greatest phase of this eclipse, which took place about 2 o'clock in the afternoon, was 0'58. The same evening, about 11 o'clock, altitudes of « Cassiopeia? and y Draconis gave the latitude 80° 13' 5" and the error of Htv 8h 18m 9s slow on Local M. T. As Mr. Scott-Hansen had made an approximate calculation of the moments of contact, 3 observers were ready with the telescope of Negretti and Zambra and the altazimuth, viz. NANSEN, SCOTT-HANSEN and JOHANSEN. As they were of course on the look-out in good time before the calculated time of 1st con- tact they shifted positions ; at the time of observation Nansen happened to be at the clock, Scott-Hansen at the telescope and Johansen at the altazimuth. At first contact both observers called out at the same moment, which was (reduced to Hw) April 5, 16h 35m 43s. As nothing is to be seen at the moment of geometrical contact, this is of course some seconds late. At the second contact the observer at the alta- zimuth called out at 1) 18h 31m 25s when the little notch was estimated to be of the same size as at I8t contact. Scott-Hansen noted the time as 2) 18h 31m 36s when the last trace vanished in the telescope. He adds the remark that the image was very sharp. NO. 6.] INTRODUCTION. CHRONOMETERS. XXI The observations have been calculated with the Besselian elements given in the Connaissance des Temps, and the results have been combined as follows : 1st contact, Htv — Gr. M. T. = 42m 12s 2nd — [1] = 41 27 Mean 41 49.5 2nd _ [2] Hw _ Gr> M T. = 41 38 Definitive mean =41 44 On account of Mr. Scott-Hansen's remark about his observation of the 2nd contact it was deemed reasonable to give it the same weight as the mean of the two others. If the two notches which were estimated alike had been exactly so, the first mean would be nearer the truth, but the difference is not of any importance. 1895 March 25 (March 26 on board). The circumstances of this eclipse which took place about 6 in the afternoon were much less favorable than the former. The greatest phase was only 0.045, and the limb of the very low sun was so boiling, especially at 2nd contact, that the observations were very difficult. No stars were observed the same day, but altitudes of ij Ursse Majoris and « Cygni were taken the day before and the day after; the mean of the results, which differ only 24" in latitude and 54" in time, was latitude 84° 8' 22" and Htv 5h 58m 51s slow on Local Mean Time. The observers were SCOTT-HANSEN at the telescope and SVERDRUP at the altazimuth. At 2nd contact both observers took care to note, as nearly as possible, the moment when the notch was apparently of the same magnitude as at 1st contact. The moments, reduced to Htv, were ( 23h 36m 49s Hansen 1st contact < { 23 36 54 Sverdrup f 0 13 42 Sverdrup { 0 14 39 Hansen Last trace in the boiling limb 0 14 54 Sverdrup XXII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. The calculation by means of the Gonnaissance des Temps gave the results ( I8t contact, Htv — Gr. M. T. = 40m 58" ) Hansen \ \ 39m 53s ( 2nd - - —»— =38 48 j f 1st contact, Hto — Gr. M. T. = 41 Sverdrupf 1 2nd — - — »— == 37 Sverdrup, last trace In this case it was not deemed safe to use the last as an independent observation, because it was made with the small instrument and a very boi- ling limb. The mean of the two others is Hw — Gr. M. T. = 39m 40". Preparations were also made for observing the Eclipse of 1895 Aug. 20 which was calculated to have a duration of about 33m. Three circummeridian altitudes of the sun the same day (some 6 hours before) gave the latitude 84° IT 49" and the error of Hw approximately 4h 31m 0s late, but the ship had a considerable south-easterly drift in these days. There was, however, a gale blowing with snow almost the whole afternoon. A clear interval, begin- ning some minutes after 1st contact, made it possible to follow the eclipse until a moment which was estimated to be 4 — 6 minutes before 2nd contact. A calculation has shown that this estimate was a couple of minutes too small. Lunar Distances. On some occasions the Moon's distance was measured from the Sun (once), Jupiter (5 times), Mars or Pollux (once each). According to nautical usage the altitudes of the two objects were measured before and after the distances in order to get, by interpolation, the altitudes at the moment of the mean of the distances; it was, however, preferred to calculate these altitudes and to use the measured altitudes as a means of completing the determinations of time and latitude. In most cases these altitudes were taken with the altazi- muth, but only in one position of the instrument; the zenith point of the vertical circle was then deduced from neighbouring observations. The measured distances will be found among the other observations with the sextant. In the computation due regard was taken to the elliptical figure of the disc due to refraction and to the small effect of the Moon's parallax in NO. 6.] INTRODUCTION. CHRONOMETERS. XXIII azimuth. For the determination of the apparent altitudes the refraction corres- ponding to the meteorological conditions was of course used; while an error affecting the true and the apparent altitude alike has only an insensible effect on the calculation of the true distance (being multiplied by the Sine of the difference between true and apparent altitude) an error in the refraction or parallax would affect the true distance by a quantity of the same order as the error itself. The results are not satisfactory. In some cases when the observations have been taken with intervals of a few days or weeks, the chronometers are unanimous in protesting against the deduced Greenwich times. As the tempe- rature during these observations was only once (1896 April 22) as high as — 16° C., and on all the other occasions between — 27° and —43°, it is prob- able that the sextant was affected with errors that would not have been of great importance for ordinary altitudes of the Sun, but which proved fatal to the delicate operation of determining the longitude by Lunar Distances. It is also to be remarked that the index error was not determined on each occa- sion but for some time considered as constant, because a determination in August 1893 in the Barents Sea and another off the mouth of Lena shortly before the enclosure in the ice had given identical results. It would of course have been better to use the altazimuth for determining the difference of azimuth between the Moon and a star or the Sun, and thence deduce the Moon's right ascension. But as it happened that the planet Jupiter was circumpolar during all the 3 years of enclosure in the ice and so was always at hand when the Sun was absent, it was found to be a much more ready means of getting an approximate longitude to observe the eclipses of Jupiter's Satellites and compare with the predicted times in the Nautical Al- manac. The results of the Lunar Distances are included in a table below (Tab. c) containing the results of these Eclipses. Eclipses of Jupiter's Satellites. The observed moment of commencement or end of an eclipse of a Satel- lite is dependent on many circumstances, the aperture of the telescope being perhaps the most important. As the predicted times are sometimes seriously XXIV GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. in error, especially for the outer Satellites, it was thought at first that a suffi- cient number of the more than 80 phenomena observed on board the Fram would be found to have been observed also in other places with known longi- tudes, in which case the error of theory could be eliminated. But only a few such cases could be found, and in two of these is turned out that the same phenomenon had been observed in 2 or more places in Europe, but with such discordances that evidently no reliable result could be obtained in this way. But as a great number of observations made in Europe and Australia in the years 1893 — 96 have been published it was thought possible to utilise the whole mass as a means of deducing empirical corrections to the predicted times for the periods of observation on board the Fram. This has been tried in the manner explained hereafter. It should be stated that the imperfection of prediction is not so much due to theory proper ; for the theory of LAPLACE with the small additions of SOUIL- LART and ADAMS would certainly be amply sufficient; but the difficulty is with the determination of the numerous constants, required by theory, but neces- sarily deduced from observations. In this respect nothing has been done, so for as I know, since the times of DELAMBRE and DAMOISEAU ; at all events the predictions of the Nautical Almanac are based on the Tables of Damoiseau, continued and corrected, for Tables I and III, by Adams (Scientific Papers, Vol. I, p. 113). But the old determination of the constants is far from satis- factory. Thus Damoiseau states in the introduction to his Tables that the adopted value of the inclination of Jupiter's equator to his orbit, 3 ° 4' 5", was determined from observations of eclipses of Sat. Ill, but that Sat. IV gave another value, smaller by 2' 47", and that this smaller value has been used for this Satellite. In this connection it may be remarked, that if the coeffi- cient of the equation tabulated in Damoiseau's Table XXIII for Sat. IV be multiplied by 1.015, corresponding to an augmentation by 2' 47" of the said angle, the eclipse of 1895 January 17, which was predicted to have a dura- tion of more than half an hour, would disappear; and in point of fact the Satellite was observed by Mr. Scott-Hansen during a large part of the pre- dicted time of eclipse without any sensible diminution of its brightness. Of course I do not mean to say that Damoiseau's Tables can be corrected in this rough manner; the remark is made only to adduce an example of a NO. 6.] INTRODUCTION. CHRONOMETERS. XXV weak point in the numerical part of the foundations. It is also expressly stated by Damoiseau that some of his constants require further investigation. In order to deduce empirical corrections which can be used for the Fra/m- observations it was first necessary to reduce the continental observations to some common standard in regard to extraneous circumstances. It is well known that the treatment of observations of these eclipses is difficult. Some 25 years ago Professor DE GLASENAPP of St. Petersburg made an elaborate investigation principally with the intention of deducing the light-equation from a large series of observations of Sat. I. By the courtesy of the author I am in possession of the original memoir, but as I am quite unacquainted with the Russian language, my knowledge of its contents rests on a very clear abstract given by Mr. DOWNING in "The Observatory", Vol. XII. It was necessary for the author's purpose to take into consideration : the aperture of the telescope, the absorption of light by the atmosphere and its dependence on the altitude, the Planet's distance from the Earth, the excentricity of Jupiter's orbit, the phase, the Satellite's angular distance from the Planet at the time of reappearance or disappearance, and the effect of the penumbra. The final result is not encouraging for the treatment of such observations. After having deduced the light-equation and two other quantities from the observations, reduced to a common standard in regard to the circumstances named above, Mr. de Glasenapp had the happy idea to solve his equations afresh, using the observed times as they stand. The probable errors in this latter case are not much greater than in the first, which means that the discordances between the predicted and the observed times of disappearance and reappearance of Sat. I may, to a large extent, be considered as accidental. For the purpose of utilising the .Fram-observations the case is so far different that there is no question about the absolute moment of the Satellite's centre being on the limb of the shadow, and that the outer Satellites are of the same importance as Sat. I. As the telescope used on board was consi- derably smaller than those generally used in observatories for the same ob- servations, it was necessary to take account of the aperture ; and it must also be admitted that the Planet's distance from the Earth may have a sensible effect on the magnitude of the "invisible segment1', i. e. the illuminated por- tion of the Satellite's disc which is at the limit of visibility for a given tele- scope. As to the absorption of light at different altitudes, the writer was in \ XXVI GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. some doubt whether it would be safe to neglect it, but finally it was decided to put it in the great bag of accidental errors, the most important of which is, perhaps, the difference in the keenness of sight for the different observers. It is true that the difference of absorption may have an effect of systematic character, because the Planet's altitude in the high latitudes of the From was of course on the average smaller than in Europe and Australia; but as this effect will be of contrary sign for disappearance and reappearance, it might be expected to make itself manifest and thus give the means for elimi- nation from the whole mass of observations. The problem to be solved is firstly to find, by pairs of observations of the same phenomenon, made with telescopes of different aperture, the breadth of the invisible segment corresponding to a standard aperture and an arbitra- rily chosen distance; then to apply the values found for disappearance (D) and reappearance (R) of the different Satellites to all the continental observa- tions taken during the period of polar observations, in order to deduce such corrections to the predicted times that they will correspond to the telescope of the From. A convenient form for the calculations has been found by the following considerations. As the connection between the variation of the illuminated portion of a Satellite, crossing the surface of the shadow, and the time, depends on the position of the chord described by the Satellite's centre during the eclipse, certain quantities must be taken out of Damoiseau's Tables, the foundation of which is the theory of Laplace contained in Mecanique Celeste, Livr. VIII. For the quantities taken from this theory the notation of Laplace has been retained as far as convenient. The signification of the letters employed below is : x the breadth of the invisible segment, as seen with a telescope of the standard aperture A, when Jupiter is at the standard distance D from the Earth, x may be expressed in parts of the Satellite's radius or in some other convenient unit. Tl and Tz the times for the same phenomenon observed by means of tele- scopes of aperture A^ and A^ but as far as possible in similar circum- stances in other respects. NO. 6.] INTRODUCTION. CHRONOMETERS. XXVII D' Jupiter's distance from the Earth at the time of observation (known from the ephemerides). 0 the ellipticity of the section of the shadow traversed by the Satellite (a little different for the different Satellites). a the semi major axis of the same section, corresponding to the mean dis- tances of Satellite and Planet. ft the jovicentric angular value of a. s the Satellite's jovicentric latitude above the plane of Jupiter's orbit at the moment of heliocentric conjunction. In the case of the shadow Laplace neglects the angle between Jupiter's equator and the plane of his orbit, because its effect would be of the same order as the square of the ellip- ticity, which is also neglected. y the angle between the Satellite's relative motion at conjunction and the circle of latitude (towards the north). Owing to the small inclinations y is never much different from 90°. tv the Satellite's jovicentric motion in one second of time, expressed in some convenient unit. The quantities s and y may be calculated by means of Damoiseau's Tables in the following manner. According to Laplace where M is the number so designated by Damoiseau and taken out of his Tables by means of the arguments given in Adams' continuation ; K is the sum of constants added in order to make all tabular numbers positive1. M — K is the quantity called £ by Laplace. The angle y is given by the equation ds cosy=^ where dv is the Satellite's jovicentric motion in its orbit. This can be found by means of the quantity called "reduction" in Damoiseau's Tables, but more readily and in some cases more accurately by the following consideration. M — K is of the form 1 In the case of Sat. II, K is given by Damoiseau as 0.6400, but has been here applied as 0.6415, because the numbers of his Table XXIV are 0.0015 too great. XXVIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. M— K= h sin H + * sin J + etc. where the rate of change of the arguments H, I etc. is so little different from the rate of change of v that they may be considered as equal during an eclipse. Consequently - = . \_ (h cos H-}- i cos I -+- etc.) = [h sin (J5T+ 90°) + i sin (/ + 90°) + etc.]. Or the arguments which have already served for finding s will, when they are' all augmented by 90°, give cos y. D In the figure A is the centre of the elliptic shadow, AD = a, C the centre o of the Satellite, CB the line of its relative motion, AB= -r . a, ABC = y. P The Satellite is supposed to be in such a position that a certain fraction a of its radius r is outside the shadow. The connection between the difference of observed times of a disappearance (or reappearance) and the variation of the breadth of the invisible segment depends on the angle DAC = u. This of course varies during the observations, but may here with sufficient accuracy be considered as constant for a given phenomenon, corresponding to a given value of the fraction a. It would not be difficult to take account of the phase of the Satellite, which can never exceed 0.02 r, but it is also easily seen that it is of no importance in this connection. The angle u can be determined by the triangle ABC, where the angle ACB = 90°-{-u— y and cos (y — u) sin y AB ' ~AC~' Now as the elliptic radius corresponding to the direction u is, neglecting the NO. 6.] INTRODUCTION. CHRONOMETERS. XXIX square of the ellipticity, a (1 — Q sin2 «) it follows that A C = a (1 — Q sin2 u) — (1 — a)r = a [1 — Q sin2 w — (1 — a)b], when & is the Satellite's radius expres- sed as a fraction of a; from observations in recent years this is sufficiently well known. Consequently s.sin y COS ~ Here all quantities, except u, are known as soon as a convenient choice of the fraction a is made. The equation gives 2 values of y— u, one for D, the other, with contrary sign, for R. The angle u is considered as negative on the south side of AD. It is seen from the same figure that if the breadth h of the segment outside the shadow is measured along the elliptic normal through C, and £ is the angle between this normal and A C, where, with the same accuracy as before, tg f = e sin 2% ... (2) then the angle between the normal and the direction of relative motion is 90°-|-M — y + £> ana" consequently, if dt is the increment of time and dh = —k.dt, k = tv.sm (y—u—C) ... (3) The same equation holds good for reappearance, where h increases with the time, for then y— u and k are negative. The quantity of light received from the Satellite at a given moment may be supposed to be proportional to the apparent size of the illuminated seg- ment. As the dimensions of the Satellites are between V» and Va of the dimensions of the shadow-section, the curvature of the small part of the con- tour intercepted by the satellite during the observations (which can easily be taken into consideration) has been neglected in the following, because its small influence is very nearly constant for each Satellite and will not disturb the final results. The most extreme eclipses of Sat. IV, where observations of the same D or R made with different instruments may extend over several minutes, the Satellite almost grazing the shadow, must be left out of con- sideration as unfit for our purpose. The segment 2 being thus considered as an ordinary segment of a circ e it can be expressed as a function of the breadth h by the series XXX GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 2 = 1 V2T.fe*{l-A |_ A- ^ -...}... (a) the convergence of which will be sufficiently rapid for admissible values of h. If 2 and h correspond to an observation at the distance D, 2' and h' to another distance D', then according to the above supposition fl2 from which it follows that 2' and or, if for a moment (-IT I is called f, *-/»(' 10 r Now, when D is the mean distance of Jupiter from the Sun, which is also a mean distance from the Earth, the numerical value of the coefficient of - can never exceed 0.04, and as h is certainly only a fraction of r for all but the smallest telescopes, the second term may safely be neglected. Consequently an observation at the distance Df can be reduced to the dis- tance D by writing I jr J . h for h'. If a disappearance or reappearance at the distance D is observed at the moment T by means of a telescope of aperture A (in which case h = x) and the same phenomenon occurred at the moment T, for an aperture At giving the invisible segment 2lt it is assumed that the quantity of light is proportional to the square of the aperture, or y J2 — y A 2 <^> t ^i — *—• 4 • ./I 1 j and further that the difference between the segments may be found with sufficient accuracy by a differential formula, or 2l — 2 = d 2, where = 21/2 hr(l — £-\.dh and Ah = — k.dt = k (T—TJ. \ 2rJ NO. e.] INTRODUCTION. CHRONOMETERS. XXXI If this last supposition should in some cases prove insufficient, the series (a) will give the means for further corrections. The accuracy aimed at in the reduction depends of course on the accuracy of the observations, but as this is manifestly not great no such refined corrections have been found necessary. Now and on division by or, neglecting the second term and multiplying by x Similarly for another observation of the same phenomenon, made with a tele- scope of aperture A^ at the moment T2 and by subtraction Kft'-®1]— »»tr,-W If the two observations have been made with the Planet at the distance D' instead of D, x is to be replaced by (-77) x, and consequently if -*(§) ** AY then x may be found by the equation ax = ck (T2 — T,) ......... (6) expressed in the same units as w, T2 — T, being given in seconds. As soon as x has been determined in this manner by pairs of observa- tions, every observed moment T' found by means of an aperture A' at dis- XXXII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. tance D' may be reduced to the standard aperture and distance by tbe for- mula As to the application of the equations (1) ... (6) only a few remarks are necessary. The standard distance D was taken as 5.20 and a small table formed for the function c (equation (4)) with the argument logD' from 0.60 to 0.80. The standard aperture was taken as that of the Fram telescope (7 4\2 -ji 1 tabulated from A' = 6.0 to 26 cm., the last being the largest aperture employed for the present observations. The fraction a in equation (1) was taken as 0.2; evidently the choice is not of great importance, the function k having a period equal to the time of revolution of Jupiter. The ellipticity of the different sections of the shadow has been calculated by Laplace in the chapters of Livre VIII containing the special theories for each Satellite, on the supposition that the ellipticity of Jupiter is 0.07130, the reciprocal of which is 14.025; but as Damoiseau states in the introduction to his Tables that he has employed the value 13.492, the numbers of Laplace were multiplied by 1.0395. More recent observations give a somewhat smaller ellipticity, but when using Damoiseau's Tables his values should clearly be retained. The diameters of the Satellites employed were those determined by Mr. BARNARD with the great Lick refractor (Monthly Notices of the R. A. S., Vol. 55) compared with his value of Jupiter's equatorial diameter (Astronomi- cal Journal, Vol. 14). As the values of « for the four satellites, the equatorial semidiameter of Jupiter being taken as unity, are given by Damoiseau in the appendix to his Tables (p. 196), the fraction 6 could be calculated for the different Satellites. As it will be convenient to have x, the breadth of the standard invisible segment, expressed in terms of the Satellite's radius, to must be expressed in the same units. If t is the half duration of a central eclipse, as given by Damoiseau, and expressed in seconds, ip--.i NO. 6.] INTRODUCTION. CHRONOMETERS. XXXIII is the relative velocity of the Satellite, expressed in parts of a, and as r = b . a, 1 w = b .t will give w, k and x in parts of the Satellite's radius. If S is the time of synodic revolution of the Satellite, /? is determined by the equation The following Table contains these several quantities which formed the basis of the calculation; it gives 10 w instead of w because it was convenient to multiply both sides of equation (6) by 10. Barnard's value of Jupiter's equatorial diameter at the distance 5.20 is 38".E I II III IV p 0.0745 0.0747 0.0751 0.0758 log /3 9.2236 9.0227 8.8132 8.5701 a 0.9951 0.9923 0.9877 0.9783 2r 1".048 0".874 1".521 1".430 b 0.0273 0.0229 0.0400 0.0379 log 10 w 8.9533 8.9291 8.5913 8.4883 The projected velocity k was calculated for the three inner Satellites at intervals of about half a year (a whole number of synodical revolutions in every case) from 1893.0 to 1898.5 ; for Sat. IV whose latest period of eclipses began in 1895 it was calculated with intervals of 67 days (4 synodical revolu- tions) from 1895.2 to 1897.1. The values which are given below were plotted on cross-ruled paper and curves drawn, from which the value could easily be taken out for any given eclipse. The Table gives 10 k. Sat. I. Sat. II. D R D R 1893.00 0.0839 -0.0838 1893.00 0.0678 -0.0675 93.50 832 832 93.50 640 639 94.00 836 837 94.00 641 643 94.50 848 850 94.49 679 683 95.00 866 868 94.99 738 742 95.50 882 884 95.49 795 799 96.00 894 895 95.98 835 838 96.50 898 898 96.48 849 849 97.00 894 893 96.98 836 833 97.49 883 881 97.47 799 795 97.99 868 866 97.97 747 743 98.49 0.0853 — 0.0850 98.46 0.0695 -0.0691 XXXIV GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Sat III. Sai IV. D R D R 1893.02 0.01666 —0.01657 1895.23 0.01139 -0.01142 93.51 1182 1172 95.41 1738 1751 94.00 1399 1392 95.60 2163 2180 94.49 2059 2065 95.78 2491 2508 94.98 2762 2781 95.% 2738 2755 95.47 3348 3372 96.15 2916 2929 95.96 3740 3757 96.33 3028 3035 96.45 3899 3902 96.51 3077 3078 96.94 3819 3806 96.70 3063 3058 97.43 3518 3494 96.88 2987 2978 97.92 3035 3012 97.06 0.02852 —0.02837 98.41 0.02429 -0.02414 For the determination of the breadth of the invisible segment all obser- vations of disappearances and reappearances in the years 1893 — 98, published in the Monthly Notices and in the Astronomische Nachrichten, were exami- ned, and those selected where the same phenomenon had been observed by means of two or more telescopes of different aperture. Each pair of such observations gave an equation, which was retained in the form of equation (6) with a (which depends on the apertures) as coefficient of x, though it was an unfavorable circumstance that most of the observations had been taken with instruments so far superior to that of the Fram in regard of size, that the weight of an equation was often much smaller than would have been the case with a somewhat larger standard aperture. Some few observations with large apertures differing only 1 or 2 cm. have been omitted. In the second column of the following Table a, containing the places of observation, the following abbreviations have been used: Bs Bermerside, Ch Christiania, Gr Greenwich, Gt Gottingen, Jn Jena, Ks Kasan, Ly Lyons, Po Pola, Uc Uccle, Ut Utrecht. In some cases two observations with telescopes of nearly the same aperture have been combined into one, which is indicated by an added 2 or by a + between the places when they were different. Next follow the apertures At and A% in centimetres. Owing to the not uncommon custom of giving, in astronomical publications, the aperture in inches of the different countries, even where the metrical system has been introduced, the last figure may in some cases be inaccurate; the fraction of cm. has been retained here only when certain. The last column contains the quantity 10 ck (Tt—TJ which is designated by r. NO. 6.] INTRODUCTION. CHRONOMETERS. XXXV No distinction has been made between observations designated by the observers as good or bad. TABLE a. A, A* c 10 fc Ti-Ti 10 a Sat. I D. 1893 Nov. 6 Gr, Gr 17. 25. 1.95 .0834 13s 1.05 2.02 1895 Nov. 14 Gr, Ut 17. 26. 1.60 .0891 1 1.09 0.14 Nov. 30 .... Gr, Bs 17. 24. 1.71 .0892 —11 0.93 —1.68 1898 Jan. 20 . ... Ch, Ch 7.4 18.8 1.57 .0866 16 8.45 2.18 Febr. 14 .... March 9 .... Ch, Ch Ch, Ch 7.4 7.4 18.8 18.8 1.72 1.82 .0865 .0864 12 26 8.45 8.45 1.78 4.07 Sat. I R. .' 1893 Febr. 5 Gr, Bs 17. 24. 1.45 -.0835 14 0.93 -1.72 Febr. 28 .... Gr, Gr 5;?j 25. 1.35 -.0834 -36 20.0 4.08 March 23 .... Gr, Gr 17. 25. 1.29 —.0833 16 1.05 -1.71 Dec. 10 Ks 2, Ks 8.8 24.4 2.05 —.0836 —38 6.22 6.59 Dec. 10 Ks, Ks 8.1 9.6 2.05 —.0836 15 2.40 —2.58 1894 Jan. 2 Jn, Bs 10. 24. 1.91 —.0837 -20 4.09 3.18 Jan. 23 Gr, Gr + Bs 17. 24.5 1.74 —.0837 — 9.5 0.99 1.38 Febr. 8 Jn, Bs 10. 24. 1.63 -.0838 —16 4.09 2.17 Febr. 24 .... Gr, Bs 17. 24. 1.52 -.0840 —15 0.93 1.92 March 12 .... Ks 2, Ks 9.0 24.4 1.43 -.0841 —23 5.93 2.78 March 12 .... Ks, Ks 8.4 9.6 1.43 -.0841 — 4 1.82 0.48 1895 Jan. 28 Gr, Bs 17. 24. 1.89 -.0872 3 0.93 —0.50 Febr. 13 .... Jn, Bs 16. 24. 1.78 —.0873 13 1.25 -2.03 Febr. 20 .... Ly, Bs 16. 24. 1.73 -.0874 4 1.12 -0.60 March 1 .... Ks 2, Bs 8.3 24. 1.66 -.0875 —14 7.08 2.04 March 1 .... Ks 2, Ks 8.3 9.6 . . -22 2.11 3.21 March 1 .... Ks 2, Ks 8.3 24.4 . . —19 7.13 2.77 March 31 .... Ks, Ks 10.8 24.4 1.46 -.0877 —75 3.78 9.68 1896 Febr. 25 .... Gr, Ut 9. 26. 1.84 —.0896 -82 5.26 13.45 April 2 Gr, Bs 17. 24. 1.60 —.0896 —24 0.93 3.45 April 2 .... Po, Bs 16. 24. —18 1.25 2.59 May 11 Uc + Po, Gr 15. 17. 1.37 —.0897 — 8 0.43 0.98 May 11 .. Uc + Po, Bs 15. 24. —36 1.35 4.42 1897 March 22 .... Po, Gr 16. 21. 1.81 —.0887 7 0.93 —1.13 1898 May 19 . Ch. Ch 7.4 18.8 1.65 —.0854 -20 8.45 2.82 Sat. II D. 1894 Febr. 18 .... Gr, Bs 17. 24. 1.56 00648 g 0.93 -0.91 Nov. 15 .... Gr + Jn, Bs 16. 24. 1.91 .0725 65 1.09 8.97 1895 Nov. 23 .... Gr, Ut 17. 26. 1.66 .0829 g 1.09 —1.24 1898 Jan. 27 ... Ch, Ch 7.4 18.8 1.62 .0736 25(9) 845 2.97 Febr. 3 Ch, Ch 7.4 18.8 1.66 .0735 — • ' i / 39 O.TTlJ 8.45 4.76 XXXVI GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Table a (continued). 4t A, c 10 fc 2V T, 10 a r 1896 Febr. 23 Febr. 23 Sat. II R. 1893 Deo. 9 Gr, Gr 17. 25. 2.06 -.0641 -12« 1.05 1.58 Dec. 16 Gr, Bs 17. 24. 2.02 —.0642 —11 0.93 1.43 1894 Jan. 3 Ks, Ks 8.1 24.4 1.90 —.0643 —62 7.42 7.56 Jan. 17 . Jn, Gr 10. 17. 1.79 —.0646 + 4 3.16 -0.46 Febr. 18 .... Gr, Bs 17. 24. 1.56 —.0651 -14 0.93 1.41 1895 Jan. 11 Ks 2, Ks 8.0 24.4 1.98 —.0749 -52.5 7.71 7.77 Febr. 12 .... Jn + Gt, Bs 16. 24. 1.79 -.0758 —30 1.20 4.08 March 16 .... Ks2, Bs 10.1 24. 1.56 —.0770 — 5.5 4.35 0.66 March 16 .... Ks 2, Jn 10.1 16. - - + 6.5 3.10 -0.78 1896 Febr. 13 .... Gt, Jn 8. 16. 1.89 —.0844 -28.5 6.78 4.56 March 16 .... Gr, Bs 17. 24. 1.72 —.0846 —27 0.93 3.92 March 16 .... Uc, Ut 15. 26. - - —33.5 1.62 4.85 April 10 Po, Bs 16. 24. 1.55 —.0847 +21 1.25 -2.75 April 17 .... Gr, Bs 17. 24. 1.50 —.0847 —27 0.93 3.45 May 19 Gr, Ut 17. 26. 1.49 —.0848 — 13 1.09 1.65 1897 May 20 Gr, Ut 17. 26. 1.46 -.0803 —33.5 1.09 3.92 Sat. IB D. 1893 Nov. 10. .. . Gt, Uc 9.2 15. 2.11 0.0126 112 4.04 2.97 1894 March 12 .... Ks 2, Jn + Ks 8.2 10. 1.43 .0162 —18 2.55 -0.42 March 12 .... Ks 2, Ks 8.2 24.4 . . 14.5 7.13 0.34 1895 Nov. 11 Ks 2, Ks 8.8 10.8 1.59 .0366 -9(?) 2.44 -0.52 Nov. 11 Ks 2, Ks 8.8 24.4 m . 20 6.22 1.16 Nov. 18 Gr, Ut 17. 26. 1.63 .0368 45 1.09 2.72 1896 March 19 .... Gr, Bs 17. 24. 1.70 .0385 42 0.93 2.74 1898 Jan. 7 . Ch, Ch 7.4 11.8 1.49 .0290 30 6.07 1.30 Sat. Ill R. 1894 Jan. 28 ... Jn, Gr2 10. 20. 1.71 —.0147 —27.5 3.69 0.69 Jan. 28 ... Gr, Gr 17. 25. -49 1.05 1.23 March 12 .... Ks, Jn + Ks 8.1 10. 1.43 -.0161 —38 2.84 0.87 March 12 .... Ks, Jn + Ks 8.4 10. . - -69 2.26 1.59 Octbr. 13 ... Ks, Ks 9.6 24.4 1.68 -.0251 —52 5.02 2.19 1896 March 12 ... Jn, Bs 16. 24. 1.74 -.0385 -29 1.25 1.95 1897 Febr. 26 .... Po, Ut 16. 26. 1.87 —.0367 +16 1.41 -1.10 April 10 .... Jn + Po, Bs 16. 23. 1.71 —.0360 - 3 1.16 0.18 Sat. l\ D. 1895 Nov. 14 Gr, Ut 17. 26. 1.60 0.0261 0 1.09 0.00 1896 April 13 .... Gr, Bs 17. 24. 1.53 0.0300 —16 0.93 -0.73 April 13 .... Jn + Uc, Ut 15. 26. - - +40.5 1.52 1.86 Sat. IV R. Gt, Gr Gt, Bs 8. 8. 17. 24. 1.85 -.021! 44 104 7.10 8.03 2.40 5.66 NO. e]. INTRODUCTION. CHRONOMETERS. XXXVII When the equations are solved according to the method of least squares, but separately for ID, I R, etc. they give the results contained in the following table, where n is the number of equations, the final columns giving x in seconds of arc for the distance 5.20, adopting Barnard's values of r as above. n X X r D R D R D R Sat. I. . . 6 25 0.315 0.447 O."165 0."234 - II ... 5 16 0.499 0.815 0. 218 0. 356 - Ill ... 8 8 0.208 0.378 0. 158 0. 288 - IV ... 3 2 0.49 0.54 0. 35 0. 39 An inspection of these numbers gives two results : 1. For all Satellites the numbers are greater for R than for D. This is only what might be expected, because it is quite natural that the quantity of light necessary for enabling the observer to catch the first glimpse of an emerging Satellite must be on the average greater than what is necessary when he is following a vanishing point of light. 2. For the three inner Satellites the fraction of the radius that must be outside the shadow at the moment of observation is greater for a smaller Satellite than for a bigger one, which is also what might be expected when the albedo of their surfaces is not much different. If the albedo had been the same for all three, the product x V2ras, with x expressed in seconds, should be nearly constant (but of course different for D and R). An inspection of the last two columns of Table a shows that the values of x are too uncertain to give any information on this delicate point, but it was desirable, in order to diminish the effect of accidental errors, to combine the equations for these three Satellites. The values of x expressed in seconds are not more different than is compatible with the assumption of their identity. For I and II this is not very different from supposing the same albedo, but for III, which is the largest, it would imply the supposition of a somewhat inferior albedo. In this respect it is interesting to compare the rela- tive values of the diameters as found by PICKERING by photometric measure- ments, on the supposition of the same albedo, with those of BARNARD and also with those of MICHELSON which were determined by an entirely different method. The table below contains these numbers. XXXVIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Pickering Barnard Michel son I. 1.00 1.00 1.00 II. 0.94 0.83 0.92 m. 1.18 1.46 1.34 IV. 0.70 1.37 1.28 It is apparent that the albedo of III is really somewhat smaller than that of I and II. For IV the difference is very considerable; the above values of x point in the same direction, but by reason of the paucity of the observa- tions they are too uncertain to permit any comparison with Pickering's results. The solution of the equations for I, II and HI on the supposition named above gave the results : For I, II, m D : x = O."178 ± O."038 - I, II, III R : x = 0."263 ± O."034 For combination with the already calculated values of the velocity k they were again converted into parts of the Satellite's radius as follows : D R I. 0.340 0.501 II. 0.408 0.601 HI. 0.234 0.345 For Sat. IV the values of x must be retained as they stand. They are not of much importance for the present purpose. The next step was to apply the values of x to the observations of 1893 — 96 in order to reduce them to the aperture of the ^raw-telescope by means of equation (7) and to compare the reduced times with the predictions of the Nautical Almanac. The results are contained in Table b where A' is the (7 4\ 2 -jp\ — 1, T' — NA is the diffe- A 1 rence between the observed and the predicted time, T — T' the reduction as calculated by equation (7), and T — NA the correction which must be applied on the times of the Nautical Almanac in order to make them applicable to the From, instrument. The list contains all the published observations exclu- ding only those in the years 1893 and 1896 which fall quite outside the arctic observations of the phenomenon in question. The remarks which in many cases are added to the original observations, were omitted; only a: after the number indicates some source of uncertainty as haze, bad images, twi- NO. 6.] INTRODUCTION. CHRONOMETERS. XXXIX light etc. The places of observation are the same as before with addition of Windsor in New South Wales. An asterisk indicates a phenomenon which was also observed on the Fram. TABLE b. A' 10 a' a; c 10 /,• T'-NA T-T T-NA Sat. I D. x = 0 340. 1894 Octbr. 12 ... Kasan 24.4 —3.08 1.67 0.0857 + 519 -21s +30" Nov. 11 ... Bermerside 24. —3.07 1.88 860 +30 —19 +11 Dec. 20 ... — 24. —3.07 2.02 864 +30 —18 + 12 1895 Octbr. 29 ... — 24. -3.07 1.50 890 +21: -23 - 2: Nov. 14 ... Greenwich 17. -2.76 1.60 891 +31 -19 + 12 Nov. 14 ... Utrecht 26. —3.13 1.60 891 +32 —22 + 10 Nov. 30 ... Greenwich 17. —2.76 1.71 893 +36: -18 + 18: Nov. 30 ... Bennerside 24. —3.07 1.71 893 + 25: —20 + 5: Dec. 7 ... Greenwich 17. -2.76 1.75 893 + 15 -17 - 2 Dec. 16 ... Utrecht 26. —3.13 1.81 893 +17: —19 - 2 18% Jan. 17 ... Greenwich 10. —1.34 1.93 895 +87: - 8 +79: Jan. 22 ... — 17. —2.76 1.93 0.0895 + 6 -16 —10 Sat. I R. x = 0.501. 1893 Dec. 10 ... Kasan 24.4 -4.55 2.05 -0.0836 -39» +2&> -13a Dec. 10 ... — 8.1 -0.83 2.05 836 — 8 5 — 3 Dec. 10 ... — 9.6 -2.04 2.05 836 + 7 12 +19 Dec. 15 ... Greenwich 17. —4.05 2.03 836 -23 24 + 1 Dec. 17 ... Bermerside 24. —4.52 2.01 836 -141: 27 -114: Dec. 17 ... Jena 10. —2.48 2.01 836 —14 15 + 1 1894 Jan. 2 ... Bermerside 24. —4.52 1.91 837 -83: 28 —55 Jan. 2 ... Jena 10. -2.48 1.91 837 —63 15 —48 Jan. 23 ... Greenwich 25. — k58 1.74 838 —14 32 +18 Jan. 23 ... — 17. —4.05 1.74 838 - 7: 28 + 21: Jan. 23 ... Bermerside 24. -4.52 1.74 838 —19 31 + 12 Jan. 25 ... Jena 10. -2.48 1.73 838 —10 17 + 7 * Febr. 8 ... Bermerside 24. -4.52 1.63 839 —24 33 + 9 Febr. 8 ... Jena 10. —2.48 1.63 839 — 8 18 + 10 Febr. 24 ... Greenwich 17. -4.05 1.52 840 — 5 '32 +27 Febr. 24 ... Bermerside 24. -4.52 1.52 840 -20: 35 + 15: March 3 ... Jena 10. -2.48 1.48 840 +24? 20 +44? March 12 ... Kasan 24.4 -4.55 1.43 841 o 38 +33 March 12 ... — 9.6 -2.04 1.43 841 + 16 17 +33 March 12 ... — 8.4 —1.13 1.43 841 + 20 9 +29 March 19 ... Jena 10. -2.48 1.39 842 +40 21 +61 Dec. 27 ... Bermerside 24. —4.52 2.02 868 - 1 26 +25 Dec. 29 ... — 24. —4.52 2.01 868 —10 26 +16 1895 Jan. 5 ... — 24. -4.52 2.00 869 -67 26 —41 Jan. 14 ... GiiUingen 16.1 —3.95 1.96 870 +82: 23 +105: Jan. 21 ... Bermerside 24. —4.52 1.93 870 -24 27 + 3 Jan. 28 ... Greenwich 17. -4.05 1.89 871 —18 24 + 6 Jan. 28 ... Bermerside 24. -4.52 1.89 871 ^ —15 27 +12 XL GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Table b (continued). • 4' 10 a' a; c 10 k T'-NA T-T' T-NA 1895 Febr. 8 ... Windsor 20. -4.34 1.81 —0.0872 —33s +27s — 6" Febr. 11 ... Greenwich 17. —4.05 1.79 873 + 4 26 +30 Febr. 13 ... Bermerside 24. — 1.52 1.78 873 — 2: 29 +27: Febr. 13 ... Jena 16. —3.90 1.78 873 —15 25 +10 Febr. 20 ... Bermerside 24. —4.52 1.73 874 —16 30 +14 * Febr. 20 ... Lyons 16. -3.97 1.73 874 —20 26 -f 6 * Febr. 23 ... Windsor 20. -4.34 1.70 874 -27 29 + 2 March 1 ... Bermerside 24. -4.52 1.66 875 —11: 31 + 20: March 1 ... Kasan 9.6 —2.04 1.66 875 —19 14 — 5 March 1 ... — 24.4 -4.55 1.66 875 —16 31 +15 March 1 ... — 8.1 -0.83 1.66 875 + 2 6 + 8 March 1 ... — 8.4 —1.13 1.66 875 + 4 8 +12 March 8 ... Jena 16. —3.90 1.62 876 — 9 27 +18 March 8 ... Uccle 15. —3.79 1.62 876 -12 27 + 15 March 11 ... Windsor 20. -4.34 1.59 876 -36 31 - 5 March 18 ... — 20. —4.34 1.54 876 -30 32 + 2 March 22 ... Utrecht 26. -4.60 1.52 876 —12 35 +23 March 31 ... — 26. —4.60 1.46 877 —24 36 + 12 March 31 ... Kasan 24.4 -4.55 1.46 877 - 7 36 +29 March 31 ... — 10.8 —2.66 1.46 877 +68 21 +89 April 3 ... Windsor 20. -4.34 1.45 877 -24 34 + 10 April 7 ... Bermerside 24. -4.52 1.42 877 —12 36 +24 April 7 ... Utrecht 26. -4.60 142 877 -20 37 +17 April 23 ... Greenwich 17. -4.05 1.35 878 + 3 35 +38 April 26 ... Windsor 20. -4.34 1.33 879 -14 37 +23 May 12 ... — 20. —4.34 1.27 880 -18: 39 + 21: 1896 Jan. 27 ... Windsor 11. —2.90 1.93 896 +24 17 +41 Jan. 31 ... Pola 10. —2.47 1.92 896 + 4 14 + 18 Febr. 4 ... Windsor 20. —434 1.92 896 —10 25 +15* Febr. 9 ... Bermerside 24. -4.52 1.91 896 —29 26 - 3 Febr. 16 . . Jena 16. -3.90 1.88 896 —15 23 + 8* Febr. 19 ... Windsor 20. -4.34 1.87 896 —19 26 + 7 Febr. 25 . . Greenwich 10. -1.97 184 896 +61 12 + 73 Febr. 25 ... Utrecht 26. -4.60 1.84 896 -21 28 + 7 Febr. 27 ... Windsor 20. —1.34 1.83 896 —11 26 + 15 March 1 ... Greenwich 17. -4.05 1.81 8% 0 25 +25 March 3 ... Jena 16. —3.90 1.80 896 -54: 24 -30: March 6 ... Windsor 20. -4.34 1.78 8% —19 28 + 9 March 19 ... Greenwich 17. —4.05 1.70 —0.0897 + 1 26 +27 Sat. II D. x = 0.408. 1893 Aug. 24 ... Greenwich 10. -1.61 1.64 0.0637 -43s —15s -58s Sept. 25 ... — 17. —3.30 1.88 637 -119 -28 —147 Oct. 27 . . •. — 17. -3.30 2,07 637 - 9: —25 —34: Nov. 14 ... Lyons 16. —3.22 2.11 638 -35 -24 -59 • 1894 Jan. 24 ... Jena 10. —2.01 1.74 645 —112 -18 130 Febr. 18 ... Greenwich 17. —3.30 1.56 649 -44: —33 -77: Febr. 18 ... Bermerside 24. -3.68 1.56 649 —53: -36 -89: INTRODUCTION. CHRONOMETERS. XLI Table b (continued). A' IQa'x c 10 k T'-NA T-T' T-NA 1894 Nov. 15 ... Greenwich 17. -330 1.91 0.0725 +78s —24" +54* Nov. 15 ... Bermerside 24. -3.68 1.91 725 +132: -27 +105: Nov. 15 ... Jena 16. -3.17 191 725 + 56 —23 4-33 Nov. 22 ... Greenwich 17. -3.30 1.94 726 +30 -23 + 7 Dec. 10 ... Jena 16. -3.17 2.01 0.0730 +60 —21 +39 1893 Dec. Dec. 1894 Jan. Jan. Jan. Jan. Jan. Febr. Febr. Febr. March 15 March 22 1896 Febr. Febr. Febr. Febr. 16 16 3 3 17 17 24 11 18 18 1895 Jan. 4 Jan. 11 Jan. 11 Jan 11 Jan. 18 Febr. 5 Eebr 12 Febr. 12 Febr. 12 Febr. 12 Febr. 15 Febr. 19 March 16 March 16 March 16 March 16 April 17 April 20 April 24 6 6 13 13 March 9 Bermerside 24. -3.68 1.51 0.0824 +52 —30 +22 Utrecht 26. —3.75 1.62 829 +65: -28 +37:* Greenwich 17. -3.30 1.66 830 +107 -24 +83 Utrecht 26. —3.75 1.66 830 +98: -27 + 71: Windsor 11. -2.39 1.93 0.0839 +35 -15 +20 * Sat. II R. x = 0.601. Greenwich 17. -4.87 2.02 —0.0642 0" +37" +373 Berraerside 24. —5.43 2.02 642 —11 42 +31 Kasan 24.4 -5.46 1.90 643 —29 45 + 16 — 81 —1.00 1.90 643 +33 8 +41 Greenwich 17. -4.87 1.79 645 + 8 42 +50 Jena 10. —2.97 1.79 645 + 4 26 +30 — 10. -2.97 1.73 647 +11 26 +37* Pola 16. —4.67 1.61 650 -39: 45 + 6: Greenwich 17. -4.87 1.56 652 + 4 48 +52 Bermerside 24. —5.43 156 652 —10 53 +43 Kasan 9.6 —2.45 1.41 657 +28 26 +54 Uccle 15. -4.55 1.38 658 —32 50 + 18 Bermerside 24. —5.43 2.00 -0.0745 -34 36 + 2 Kasan 24.4 -5.46 1.98 748 —52 +37 —15 — 6.6 + 1.55 1.98 748 7 —10 —17 — 10.8 —3.18 1.98 748 + 8 +21 +29 Greenwich 17. -4.87 1.95 751 -44 33 —11 Jena 16. -4.67 1.84 757 -43 34 g Bermerside 24. —543 1.79 759 —76 40 -36 « Jena 16. -467 179 759 —59 34 -25* GSttingen 16.1 -4.75 1.79 759 -32 35 + 3* Lyons 16. -4.76 1.79 759 + 6 35 +41* Windsor 20. -5.20 1.76 760 -77 39 -38* Greenwich 17. -4.87 1.73 760 -65 37 —28 Bermerside 24. —543 1.56 769 -57 45 -12 Jena 16. -4.67 1.56 769 —45? 39 - 6 Kasan 10.8 —3.18 1.56 769 -66 27 —39 — 9.6 —2.45 1.56 769 —37 20 -17 Jena 16. -4.67 1.37 779 -64 44 —20 Windsor 20. -520 1.36 780 -71 49 —22 Greenwich 17. -4.87 1.34 781 -47 46 j^ Greenwich 25. —5.50 1.91 —0.0843 —26 34 + 8 Bermerside 24. —5.43 1.91 843 + 13: 34 +47: Jena 16. --1.67 1.89 844 -34 29 — 5 Gsttingen 8. -0.60 1.89 844 - 5 4 - 1 Bermerside 24. -5.43 1.76 846 —34 36 + 2 6 XLII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Table b (continued). A' lOa'a; c 10 fc T'-NA T-T' T-NA Sai II I D. 3 5 = 0.< 234. 1893 Nov. 10 ... Uccle 15. —1.77 2.11 0.0126 +2443 -67» +177» NOT. 10 ... Gottingen 9.2 -0.82 2.11 126 + 132: -31 + 101: Dec. 16 ... Bermerside 24. —2.12 2.02 136 + 163 -77 + 86 Dec. 23 ... Greenwich 17. —1.89 1.98 137 + 119: -70 + 49: 1894 Jan. 28 ... Jena 10. —1.16 1.71 150 +188 -45 +143* Febr. 4 ... Greenwich 17. —1.89 1.66 151 + 158 —76 + 82 March 12 ... Jena 10. —1.16 1.43 162 + 107 -50 + 57 March 12 ... Kasan 9.6 -0.95 1.43 162 +106 —41 + 65 March 12 ... — 8.1 -0.39 1.43 162 + 122 —17 +105 March 12 ... — 8.4 -0.52 1.43 162 +127 —23 +104 March 12 ... — 24.4 —2.13 1.43 162 +139 -92 + 47 1895 Jan. 21 ... Greenwich 17. —1.89 1.93 0.0287 — 48: -34 - 82: Febr. 12 ... Windsor 20. -2.03 1.79 294 + 96 -39 + 57 Febr. 26 ... Bermerside 24. —2.12 1.69 299 + 74 -42 + 32 April 10 ... — 24. -2.12 1.41 314 + 77 -48 + 29 Nov. 11 ... Kasan 10.8 —1.24 1.59 0.0367 + 57? —21 + 36? Nov. 11 ... — 8.1 —0.39 1.59 367 + 65 - 7 + 58 Nov. 11 ... — 9.6 —0.95 1.59 367 + 67 -16 + 51 Nov. 11 ... — 24.4 —2.13 1.59 367 + 86 -36 + 50 Nov. 18 ... Greenwich 17. —1.89 1.63 368 + 83 —31 + 52 Nov. 18 ... Utrecht 26. -2.15 1.63 368 +128 —36 + 92 Dec. 31 ... Greenwich 17. -1.89 1.88 375 + 75 -27 + 48 Sat. Ill R. x = 0.345. 1894 Jan. 28 ... Greenwich 17. —2.80 1.71 —0.0147 —304s +112« —192s Jan. 28 ... — 25. -an 1.71 147 —353 127 -226 Jan. 28 ... Jena 10. —1.70 1.71 147 —301 68 —233 March 12 ... — 10. —1.70 1.43 162 -200 73 —127 March 12 ... Kasan 8.1 -0.58 1.43 162 —103 25 — 78 March 12 ... — 9.6 —1.40 1.43 162 - 82 60 — 22 March 12 ... — 8.4 —0.77 1.43 162 — 72 33 — 39 Oct. 13 ... Kasan 24.4 -3.14 1.68 -0.0252 -181 74 -107 Oct. 13 ... — 9.6 —1.40 1.68 252 —129 33 - 96 1895 Febr. 4 ... Windsor 20. —2.99 1.84 294 —142 55 — 87* Febr. 19 ... Greenwich 17. —2.80 1.73 298 -135 54 - 81 Febr. 26 ... Bermerside 24. —3.12 1.68 300 —131: 62 — 69: April 24 ... Windsor 20. —2.99 1.34 331 —101 67 — 34 Nov. 18 ... Utrecht 26. -3.18 1.64 -0.0370 — 64 52 - 12 1896 Jan. 29 ... Greenwich 17. -2.80 1.93 381 +131 38 +169 Jan. 29 ... Jena 16. —2.69 1.93 381 -158? 37 -121? Febr. 26 .. Windsor 20. -2.99 1.83 384 - 42: 43 + 1: March 12 ... Bermerside 24. —3.12 1.74 385 - 26: 46 + 20: March 12 ... Jena 16. —2.69 1.74 385 + 3 40 + 43 March 19 ... Greenwich 17. —2.80 1.70 386 + 21 43 + 64 April 24 ... Bermerside 24. —3.12 1.46 —0.0388 + 46: +55 +101: NO. 6.] INTRODUCTION. CHRONOMETERS. XLHI Table b (concluded). A' iOa'x c 10 k T'-NA T-T T-NA Sat. IV D. x = 0.49. 1895 Febr. 19 Greenwich 17. March 8 Jena 16. March 8 Uccle 15. —3.97 —3.82 -3.72 1.73 1.61 1.61 0.008 0.010 0.010 +23-n303 +19 9 +21 58 — 3 58 — 3 51 Sat. IV R. x = 0.54. 15 11 18 7 Nov. 14 Greenwich 17. —3.97 1.60 0.0260 + 5 56 — 1 35 4 21 Nov. 14 Utrecht 26. —4.51 1.60 260 + 5 56 - 1 48 4 8 1896 Jan. 20 — 26. —1.51 1.93 284 + 2 38: - 1 22 1 16 March 27 Greenwich 17. -3.97 1.64 297 + 1 54: - 1 22 0 32 April 13 — 17. -3.97 1.53 300 + 2 58 - 1 27 1 31 April 13 Bermerside 24. —4.43 1.53 300 + 2 42 — 1 37 1 5 April 13 Jena 16. -3.82 1.53 300 + 4 18 - 1 23 2 55 April 13 Utrecht 26. —4.50 1.53 300 + 4 47: - 1 38 3 9 April 13 Uccle 15. —3.71 1.53 300 + 3 55 - 1 21 2 34 May 16 Windsor 20. -4.25 1.34 0.0305 + 3 17 — 1 44 +1 33 1895 March 8 March 8 April 10 Jena Uccle Windsor 16. 15. 20. —4.23 1.61 1.61 1.41 —0.010 -0.010 -0.0136 -19m 58s -18 33: -13 17 + 4m 22s Hi C, —15m 36 s —14 17: — 9 11 Dec. 1 Bermerside 24. -4.91 1.72 -0.0270 - 4 31: 1 46 - 2 45: 1896 Febr. 6 — 24. -4.91 1.91 290 -4 9 1 29 - 2 40 * Febr. 23 Greenwich 17. -4.40 1.85 293 — 2 35: 1 21 - 1 14 Febr. 23 Bermerside 24. -4.91 1.85 293 — 3 35 1 31 -24 Febr. 23 GBttingen 8. -0.54 1.85 293 - 1 51 0 10 - 1 41 March 11 Windsor 20. —4.70 1.75 -0.0296 - 3 46 + 1 31 - 2 15 An inspection of the last column of Table b shows that it is no easy matter to deduce corrections to the predicted times. It is evident that the correction cannot be considered as constant for any length of time; it was therefore necessary to make some combination of the results surrounding the jFVam-observations, but in making such combinations some arbitrariness is scarcely avoidable. In the few cases where the eclipses observed on board had also been observed elsewhere the deduced correction could, for some of them, be applied without alteration, but for others a combination was pre- ferred when sufficient surrounding material was at hand. The corrections deduced from such combinations were often rounded to the nearest 5 or 10 seconds. XLIV GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. The adopted values are given in the column T—NA of the following Table c, which contains the .Fram-observations. Only in some few cases the space for correction had to be left blank owing to want of material. After the date and the observed phenomenon comes the time of observation, reduced to chronometer Hohwu, and the difference between Hw and the predicted time. The correction T — NA, applied with contrary sign, gives the error Hw — Gr. Mean Time (Hw — Gr.). Any special cause of uncertainty, mention- ned in Mr. Scott-Hansen's notes, has been accentuated by a : added to the numbers. The results of the Lunar Distances are included in the same Table, designated by d. TABLE c. Sat. Hw Hw—NA T-NA Hw-Gr. Remarks 1893 Nov. 14 II D 8fc 5n>17": +39m35s: - 1m 0»: +40m35s: Sat. close to limb. Telescope Nov. 24 c 21 23 42 33 without stand. Nov. 26 I R 2 24 58 41 52 0 0 41 52 Nov. 27 I R 20 54 6 42 8 0 0 42 8 Dec. 6 I R 17 18 49 42 43 0 0 42 43 Observer Johansen. Dec. 13 I R 49 13 21 41 46 0 0 41 46 Clear and calm. Dec. 19 I R 2 39 45 41 27 0 0 41 27 Dec. 29 I R 17 32 45: 40 54: 0 0 40 54: High wind, telesc. trembling. Dec. 31 1 R 12 2 48 42 5 0 0 42 5 Clear, calm. Good obs. 1894 Jan. 7 I R 13 58 56 42 25 + 0 10 42 15 Observer Johansen. Jan. 11 I R 2 56 11 41 44 + 0 10 41 34 A sharp observation. Jan. 20 II D 20 42 19: 40 42: - 1 30 42 12: Sat. already disappeared. Jan. 20 II R 22 58 46 41 57 + 0 35 41 22 Jan. 21 III D 2 2 25 Difficult, see note 1. 2 3 50 43 17 + 1 50 41 27 Barely visible till now. Jan. 21 III R 3 39 15: 37 57: - 3 40 41 37: Some seconds late, see note 2. Jan. 24 II R 12 16 52: 42 3: + 0 37 41 26: Some haze. Jan. 25 I R 6 47 53 41 40 + 0 10 41 30 A good observation. Jan. 27 I R 1 16 56 41 40 + 0 10 41 30 A good observation. Jan. 28 III D 6 4 18 Some haze, image not sharp. 5 28 43 38 + 1 50 41 48 Barely visible, see note 3. Febr. 19 I R 1 33 37 41 47 + 0 15 41 32 March 5 III D 2 11 8 42 29 + 1 20 41 9 Last glimpse. March 5 III R 3 56 58 40 53 - 1 5 41 58 First glimpse. Oct 7 II D 8 1 23 41 50 + 1 5 Oct. 7 II R 10 29 42: 41 53: 9 Nov. 3 III D 17 50 32 40 14: 9 Nov. 3 III R 20 24.4 41.5 ? — 24.9 40 45 See note 4. Note 5. First glimpse. See Note 6. NO. 6.] INTRODUCTION. CHRONOMETERS. XLV Table C (continued). Sat. Hw Hw-NA T-NA Hw-Gr. Remarks 1891 Nov. 6 I D 3h 23m 5?s Same br. as usual at II. 24 26 +41m38s + Om 15s +41m23s [Last glimpse?]. Dec. 13 I D 7 22 8: 40 35: + 0 15 40 20: Some haze, not a good obs. Dec. 18 I D 14 47 31 40 11 + 0 15 39 56 Good observation. Dec. 25 I R 18 55 26 41 29 + 0 20 41 9 First glimpse. Se note 7. Dec. 31 I R 2 21 29 41 19 + 0 20 40 59 Hansen. Very good obs. 21 43 Nansen, alum. tel. (5.3 cm.). Dec. 31 III R 4 26 18: 40 10: 9 See note 8. Dec. 31 II R 17 37 25 41 48 0 0 41 48 1895 Jan. 10 I R 17 14 6: 41 22: + 0 20 41 2: Some cirrostratus. See note 9. Jan. 14 4 later Sat. tolerably bright. 11. Calculated time for D 2h 17™ 42". Observed continually till 2b 28m, but no de- crease of brightness perceptible. Ceased for a while, but between 2b 42m and 2h 45m Sat. as bright as before — after which we left the Satellite to its fate. 12. Calculated time for D Hw 20h 6m 5a. Observed til 20t> 10", unchanged, some- what feebler than the other Satellites. Calculated time for R Hw 2H> 16m 29s ; observed 2111 llm-20m, but no increase of brightness. 13. 269 later brightness estimated as 40s before the moment noted for D. At 24h34m 27s the Sat. approached to the usual brightness. 14. First glimpse. lm 33s later same brightness as the Satellite to the left of Ju- piter [Sat. IV]. 15. Had just moved the telescope ; as soon as it had come to rest, the Sat. was seen. 16. Observation begun at 14'1 3m. 17. Waited for R till 12'i 40m, but Sat. not visible; cirrostratus. Influence of Temperature. As there were in each of the three years of the expedition periods of several months without any determination of the Greenwich Time, it was necessary to examine the general rate of the chronometer and its dependence on temperature. For this purpose the two other chronometers must also be taken into consideration. From the journal of daily comparisons the following Table d was formed, containing the difference Kt — Hw and Iv—Hw together with the daily relative rate of each. The last column (t) gives the mean temperature (Centigrade) of the interval. From the curves registered by the thermograph in Mr. Scott-Hansen's cabin the mean temperature for every day was taken out by inspection and reduced to the chronometer-shelf by means of the daily comparisons with the lower thermometer. The temperatures in Table d are means for 10 days (the intervals between the comparisons are in some few cases 9 or 11 days). As the thermograph was taken down 1896 Aug. 10 the temperature for the last 11 days is more uncertain. XL VIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL EXP. T A B L E d. Gr. T. Kt-Htv Rel. Rate Iv-Hm Rel. Rate t C. 1893 July 18 28 181' 37m 23 50 _47m 43.8 7 -47 38. 8 0.348 + 5m 16.s2 5 48. 6 3.018 14.° 73 Aug. 7 17 22 13 20 0 -47 32. 8 -47 26. 6 0. 60 0. 62 6 17. 7 6 49. 1 2. 91 3. 14 13. 77 15. 42 26 19 48 -47 25. 6 0. 12 7 8. 6 2. 17 12. 67 Sept. 0 16 18 51 19 7 -47 31 9 -47 32. 2 -0. 57 -0. 03 7 24. 0 7 49. 5 1. 40 2. 55 10. 39 13. 60 26 12 29 -47 32. 0 0. 02 8 15. 3 2. 65 14. 67 Oct. 6 12 33 -47 36. 0 -0. 40 8 34. 3 1. 90 10. 80 16 12 20 —47 36. 8 —0. 08 8 56. 4 2. 21 10. 11 26 12 10 -47 38. 8 -0. 20 9 17. 9 2. 15 8. 20 Nov. 5 12 8 -47 43. 0 —0. 42 9 34. 7 1. 68 7. 16 15 12 9 -47 48. 2 -0. 52 9 48. 7 1. 40 7. 43 25 12 10 -47 50. 3 -0. 21 9 55. 4 0. 67 6. 98 Dec. 5 12 9 -47 46. 5 0. 38 10 0. 8 0. 54 6. 30 15 12 9 -47 41. 9 0. 46 9 58. 8 -0. 20 5. 56 25 12 13 -47 33. 7 0. 82 9 59. 1 0. 03 5. 10 1894 Jan. 4 14 12 12 12 12 -47 16. 8 -46 55.8 1. 69 2. 10 10 5. 0 10 9. 1 0. 59 0. 41 6. 77 6. 55 24 12 11 —46 33. 2 2. 26 10 13. 8 0. 47 6. 69 Febr. 3 12 11 -46 11. 8 2. 14 10 17. 1 0. 33 5. 91 13 12 44 -45 46. 7 2. 51 10 20. 9 0. 38 6. 32 23 12 42 -45 20. 3 2. 64 10 26. 6 0. 57 6. 75 March 5 12 40 -44 53. 8 2. 65 10 33. 9 0. 73 7. 17 15 12 31 -44 27. 2 2. 66 10 41. 8 0. 79 7. 02 25 12 19 -44 6. 2 2. 10 10 46. 7 0. 49 6. 35 April 4 14 12 19 12 38 —43 44. 1 —43 22. 2 2. 21 2. 19 10 54. 7 11 4. 6 0. 80 0. 99 6 96 8. 23 24 12 39 -43 1. 8 2. 04 11 16. 2 1. 16 7. 28 May 5 14 12 38 12 36 -42 42. 5 —®. 30. 5 1. 75 1. 33 11 25. 6 11 33. 6 0. 85 0. 89 6. 60 6. 39 24 June 13 23 July 3 13 12 57 12 58 13 16 13 14 13 14 13 15 -42 12. 2 -41 51. 8 -41 26. 6 -40 58. 6 -40 37. 7 -40 20. 5 1. 83 2. 04 2. 52 2. 80 2. 09 1. 72 11 47. 3 12 10. 6 12 39. 4 13 12. 1 13 38. 1 14 2. 4 1. 37 1. 33 2. 88 3. 27 2. 60 2. 43 7. 30 10. 02 11. 51 13. 00 11. 33 10. 44 23 Aug. 2 12 13 15 13 12 13 15 -39 59. 0 -39 42. 7 —39 23. 2 2. 15 1. 63 1. 95 14 25. 4 14 53. 5 15 19. 6 2. 30 1. 81 2. 61 12. 04 10. 67 12. 41 22 13 13 —39 7. 6 1. 56 15 48 4 2. 88 12. 11 Sept 1 11 21 Oct 1 11 12 54 13 14 13 15 13 13 13 12 -39 2. 2 —39 0. 3 —38 58. 1 —38 58. 1 —39 0. 3 0. 54 0. 19 0. 22 0. 00 -0. 22 16 6. 9 16 27. 2 16 47. 8 17 11. 8 17 as. 3 1. 85 2. 03 2. 06 2. 40 2. 15 9. 50 8. 70 10. 09 9. 23 9. 60 21 13 50 —39 9. 0 —0. 87 17 55. 0 2. 17 10. 00 NO. 6.] INTRODUCTION. CHRONOMETERS. XLIX Table d (continued). Gr. T. Kt-Hm Rel. Rate Iv-Hw Rel. Rate t C. 1894 Oct. 21 13h 50m -39m 9.8Q + 17m 55."0 31 13 50 —39 18. 0 —0.890 18 12. 8 l.«78 + 8° 47 Nov. 10 13 52 —39 27. 5 -0. 95 18 30. 9 1. 81 8. 65 20 13 49 —39 41. 3 —1. 38 18 39. 8 0. 89 7. 00 30 13 51 —39 46. 1 -0. 48 19 1. 1 2. 13 9. 89 Dec. 10 13 52 —39 55. 1 —0 90 19 18. 4 1. 73 9. 03 20 14 23 —40 1. 9 -0. 68 19 37. 8 1. 94 8. 93 30 14 25 -40 7. 4 —0. 55 19 59. 2 2. 14 9. 82 1895 Jan. 9 14 26 —40 13. 4 —0. 60 20 19. 0 1. 98 8. 56 19 14 25 -40 17. 6 —0. 42 20 44. 4 2. 54 10. 79 29 14 26 —40 21. 9 —0. 43 21 8. 8 2. 44 10. 22 Febr. 8 14 23 -40 26. 8 —0. 49 21 26. 9 1. 81 8. 75 18 14 26 -40 29. 3 -0. 25 21 46. 5 1. 96 11. 24 March 1 14 31 —40 35. 1 —0. 53 22 2. 0 1. 41 10. 12 10 20 30 April 9 19 29 14 24 14 13 14 14 14 54 14 52 14 55 -40 37. 0 -40 38. 8 -40 48. 4 -40 52. 6 -40 56. 2 —41 5. 6 —0. 21 -0. 18 -0. 96 —0. 42 -0. 36 -0. 94 22 18. 2 22 37. 1 22 53. 7 23 16. 5 23 44. 5 24 10. 9 1. 80 1. 89 1. 66 2. 28 2. 80 2. 64 10. 78 11- 41 9. 89 11. 72 12. 91 12. 41 May 9 19 29 June 8 18 28 July 8 18 28 15 17 15 29 15 33 15 33 15 56 15 53 16 5 16 18 16 33 -41 10. 3 -41 16. 7 -41 24. 4 —41 31. 3 -41 33. 0 -41 38. 7 —41 39. 8 -41 44. 6 —41 49. 1 -0. 47 -0. 64 -0. 77 -0. 69 -0. 17 —0. 57 —0. 11 —0. 48 -0. 45 24 44. 9 25 14. 3 25 43. 9 26 10. 4 26 43. 2 27 12. 1 27 46. 4 28 16. 9 28 49. 4 3. 40 2. 94 2. % 2. 65 3. 28 2. 89 3. 43 3. 05 3. 25 ia is 13. 75 13. 52 13. 37 14. 57 13. 76 15. 20 14. 59 14. 04 Aug. 7 17 16 17 16 13 -41 54. 3 —42 0. 8 -0. 52 -0. 65 29 21. 9 29 51. 3 3. 25 2. 94 14. 45 14. 32 27 15 56 -42 5. 7 —0. 49 30 14. 4 2. 31 14. 72 Sept. 6 16 15 57 15 56 —42 10. 9 —42 15. 3 —0. 52 —0. 44 30 40. 1 31 5. 7 2. 57 2. 56 14. 37 14. 63 26 15 55 -42 24. 2 -0. 89 31 24. 2 1. 85 ia 29 Oct. 6 16 4 -42 34. 9 -1. 07 31 42. 0 1. 78 11. 79 16 15 55 —42 44. 4 —0. 95 31 59. 6 1. 76 11. 67 26 16 19 -42 55. 3 -1. 09 32 11. 4 1. 18 10. 90 Nov. 5 16 28 —43 5. 0 —0. 97 32 24. 0 1. 26 11. 35 15 16 57 -43 16. 8 —1. 18 32 33. 6 0. 96 10. 95 25 16 57 —43 29. 1 —1. 23 32 42. 3 0. 87 9. 76 Dec. 5 17 19 -43 40. 4 —1. 13 32 58. 5 1. 62 10. 95 15 17 33 -43 53. 1 -1. 27 33 10. 3 1. 18 9. 74 25 18 13 -44 6. 0 —1. 29 33 22. 8 1. 25 8. 92 18% Jan. 4 17 57 —44 21. 8 -1. 58 as 29. o 0. 62 7. 94 14 18 45 -44 41. 7 -1. 99 33 30. 2 0. 12 6. 01 24 18 39 —44 55. 7 —1. 40 33 37. 8 0. 76 10. 16 Febr. 3 19 25 —45 13. 0 —1. 73 33 40. 7 0. 29 9. 50 GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. Table d (concluded). Gr. T. Kt— Hw Rate Iv-Hw Rel. Rate t C. 1896 Febr. 3 13 igu 25m 19 44 — 45m 13.sO —45 33. 9 — 2.S09 33m 40.87 33 45. 4 O.s47 + &°64 23 19 44 -45 55. 0 —2. 11 34 2. 9 1. 75 9. 38 March 4 19 46 -46 15. 7 —2. 07 34 32. 4 2. 95 10. 56 14 19 43 -46 34. 0 — 1. 83 35 0. 2 2. 78 11. 63 24 19 41 —46 50. 1 —1. 61 35 33. 1 3. 29 13. 05 April 3 13 19 43 20 5 -47 5. 7 —V] 27. 0 — 1. 56 —2. 13 36 8. 7 36 39. 9 3. 56 3. 12 13. 46 11. 94 23 20 23 —47 47. 8 —2. 08 37 9. 6 2. 97 11. 34 May 3 12 20 24 20 22 -48 5. 1 —48 22. 0 — 1. 73 — 1. 88 37 43. 5 38 10. 8 3. 39 3. 03 12. 40 12. 47 23 20 16 —48 39. 2 —1. 56 38 49. 8 3. 55 12. 95 June 2 20 16 -48 47. 4 —0. 82 39 31. 0 4. 12 15. 72 12 20 20 —49 0. 0 —1. 26 40 7. 8 3. 68 14. 22 22 20 37 -49 16. 7 — 1. 67 40 41. 8 3. 40 12. 97 July 2 12 20 31 20 36 -49 33. 8 —49 50. 1 — 1. 71 — 1. 63 41 15. 8 41 49. 0 3. 40 3. 32 12. 84 12. 85 23 1 12 —50 5. 6 — 1. 52 42 22. 3 3. 26 12. 76 Aug. 1 11 0 55 2 9 —50 20. 6 —50 37. 4 —1. 67 —1. 68 42 46. 0 43 13. 7 2. 63 2. 77 12. 26 11. 78 22 20 4 -50 41. 1 —0. 32 43 57. 6 3. 75 12. 9 The column of rates for Kt — Hw shows some considerable irregularities which cannot be explained by any progressive term and which almost com- pletely mask the effect of temperature. In the rate of Iv — Hw the effect of temperature is very prominent (between 08.2 and 0s .3 per degree) and the casual irregularities are smaller and of a different character, from which it follows that the irregularities in the column Kt — Hw are due to Kutter. After the return of the expedition all the three chronometers were kept going for some time in the Christiania Observatory without being touched; for Hw and Iv a series of comparisons were available also from the the time imme- diately preceding the departure in 1893. Kutter arrived from Germany only some few days before the departure, but by the courtesy of Professor NEU- MAYER the writer is in possession of a series of comparisons made from the beginning of 1893 in the Deutsche Seewarte. NO. 6.] INTRODUCTION. CHRONOMETERS. LI This material was examined on the supposition that the rate could be represented in the form Daily rate = x -f- ty where t is the temperature. For Htv after the return an attempt was also made to introduce a term proportional to the time, but it was found quite insensible. The results are contained in the following synopsis, where n is the number of equations employed. n X y Zv* w^2 HohwO Kutter . ( 1893 ' '\ 1896, 97 / 1893 16 79 15 + 2.s21 ± OM65 + 2. 00 ± 0. 048 — 0. 88 ± 0. 194 — O.sl72 ± O.S0127 - 0. 192 ± 0. 0056 + 0. 056 ± 0. 0325 0.053 0.073 0.100 Ivcrsen ' '{ 1896, 97 / 1893 "\ 1896 79 22 14 - 1. 93 ± 0. 054 - 0. 45 ± 0. 245 — 0. 76 ± 0. 445 + 0. 022 ± 0. 0062 + 0 236 ± 0. 022 + 0. 270 ± 0. 040 0.091 0.400 0.157 It will be seen that Kt has the smallest temperature-coefficient, but that its constant term has changed considerably more from 1893 to 1896 than the constant term for the other two. From Table d it is also apparent that a similar change in the opposite direction has taken place in the interval. The relatively large probable errors of the constant terms depend chiefly on the choice of 0° as the standard temperature, the mean temperature during the comparisons being of course considerably higher.1 The last column gives the mean of the squares of residuals (v) as a good means for comparing the qualities of the three chronometers. Hohwti is evidently the best of the three and it was deemed safest to rely solely upon it for the intervals without observations. A formula deduced from comparisons ashore is of course not immediately applicable on board, because the exterior conditions, especially the humidity, in a narrow ship's cabin are very different from those of an observatory room. That these different conditions affect not only the constant term but also the temperature ' For Kt in 1893 it was found more convenient to count the temperatures from 10°, and the constant term was found as — O.s32 ± 0.S194 for this temperature, so that the probable error for 0° should have been considerably higher than that given above; but as the mean temperature during the comparisons in Hamburg had been higher than in Christiania, the value for 10° was retained in order not to prejudice the chronometer as compared with the other two. LII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORVV. POL. EXP. coefficient, is apparent from the fact that the relative temperature coefficient of Iv — Htv on board is sensibly smaller than the difference between the above values of y for Iv and Hw, both in 1893 and in 1896. Some trials were made in order to throw some light on this point. If the values of the clock error as determined 1) by the telegraphic signals be- fore and after the expedition, 2) by the two solar eclipses observed on board, and 3) by the eclipses of Jupiter's Satellites and by Lunar Distances, are called 1) the signal points, 2) the solar points, and 3) the satellite points res- pectively, the problem to be solved may be expressed thus : To draw a curve going exactly through the signal points, through or very near the solar points and among the satellite points which are rather widely dispersed, especially during the two first winters ; the whole time with due regard to temperature. As it happened that the mean temperature in the intervals between the signal and the solar points was somewhat different, an attempt was first made to determine the constant term x separately for the three intervals by intro- duction of the temperature coefficient — 0.9189, the mean of the values found in Christiania with due regard to weight; that is to say x = daily rate -f0.8189 t. The result was : Gr. T. Hw-Gr. Mean Rate t x 1. 1893 2. 1894 a 1895 4. 1896 July 18 .... April 5 .... March 25 ... Aug. 22. ... 20h Om 16 51 23 15 21 0 42m50» 41 44 39 40 35 33 -0.«253 -0. 350 -0. 479 + 8.°822 9. 722 12. 246 1.8415 1. 487 1. 835 It may have some interest to compare the mean rate of Hw with those of Kt and Iv for the same intervals : Kt-Gr. Rate Iv— Gr. Rate 1. 2.- 3. 4. — 1 57 — 1 6 -15 8 +0.8677 4-0. 144 —1. 63 + 48m 6s 52 40 62 24 79 31 4-1.8Q5 4-1. 65 +2. 08 NO. 6.] INTRODUCTION. CHRONOMETERS. LIII The increasing value of x for Htv with increasing temperature seems to indicate that the temperature coefficient had a smaller numerical value on board than ashore. It was next tried to form some means of the satellite points, by which the number of intervals was increased from 3 to 7 ; and by putting y = — 0.S10 it was found that x could be made approximately con- stant for all the intervals except one (1894 November— 1895 March) where it was sensibly (about 0.84) smaller. No pendulum observations were made during this period. The means of the satellite points being, however, rather uncertain, these numbers are not reproduced here. As it was apparent from these trials that the second solar eclipse, whose conditions were much less favorable than those of the first, introduced some constraint if the satellite points of the preceding winter were not to be enti- rely neglected, it was lastly tried to leave it out and to use the two remai- ning equations for a direct determination of x and y, viz : 1893 July 18—1894 April 5, x + 8.822 y = — 0.8253 1894 April 5—1896 Aug. 22, x + 11.202 y = -0. 4265 which give x = 0.8390 and y = — 0.S073 and would imply a correction of -f- 12" to the result of the second solar eclipse, corresponding to a somewhat early observation of the second contact as compared with the first, parti- cularly for Sverdrup's observation with the smaller instrument. By putting in round numbers y = — O.oQSO and determining x from the mean temperature of the whole time (10.°656 C) and the mean rate (— 0.S3864) viz : x = +0."466, only 3 seconds were sacrificed from the first solar eclipse, which brings the result nearer to the mean of 1st and 2nd contact, estimated as corresponding. As these values seemed to be slightly more concordant with the satellite points, the formula Daily rate = 0.S466 — 0.S080 t was finally adopted. On this basis the first table of the "Results", containing the error of chronometer Hohwu for every 10th day, bas been calculated. It may be noticed that the rate of Hw during the 11 series of pendulum observations, with temperatures between +5° and +15° C, as calculated by this formula, nowhere differs more than ±0."1 from the values obtained in LIV GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. the manner mentioned above, with y = — 0.810 and x only approximately constant during the several intervals; in^most cases the values obtained by both methods are practically identical. If the adopted values of the clock error Hw — Gr. are compared with the corresponding values following from the eclipses of Jupiter's Satellites (Table c), and the differences are grouped by D and R, the mean value, in the sense obs.— comp., is — 14.S2 for D and +13.84 for R, according well with the expectation that there would be a greater absorption of light in these high latitudes, where the planet's average altitude is smaller than in Europe and Australia. When the three periods of observation of Jupiter's Satellites are considered separately, the mean difference R — D is always positive; but it must be added that the symmetrical division holds good only for the whole mass of observations; if the same condition were to be fulfilled for each period separately, the curve ought to be shifted about 17s downwards at the begin- ning of 1894 and 11s upwards at the beginning of 1895. But during both these winters the observations of D were so far less numerous than the ob- servations of R that no correction could safely be deduced from this consi- deration. For the last winter, where the observations of D are in excess and the satellite points are on the whole much less dispersed, the condition of symmetry is nearly fulfilled. The calculated values of Hw — Gr. M. T. may of course be several seconds in error and it is possible that this error may in some places reach the amount of ±20". An error of 20s or 5' in longitude represents 1.6 km. in latitude 80° and 0.8 km. in 85°. Voyage along the Coast of Siberia. The astronomical observations taken before the enclosure in the ice have all been reduced, not only because the track of the ship in these difficult regions has an interest in itself, but also as forming the foundation for the determination, by compass bearings, of the situation of numerous islands and some points on the continent not to be found on previous maps. NO. 6.] INTRODUCTION. VOYAGE ALONG THE COAST OF SIBERIA. LV The compass is, however, not a very trustworthy instrument in these high latitudes. Owing to the feeble intensity of the horizontal component of the earth's magnetism the local influence on board, as well as its variations, attain relatively greater importance than in lower latitudes. Between the de- parture from Vardo 1893 July 21 and the enclosure in the ice on September 22 Mr. SCOTT-HANSEN took in all 65 compass-bearings of the Sun or a star, giving the sum of magnetic declination and local deviation, and 4 direct deter- minations of the deviation by mutual settings between the compass on board and another compass placed at a convenient distance ashore or on the ice. In order to separate the declination and deviation it was necessary to examine the declination first. Professor NEUMAYER'S isogonic chart for 1895 extends to 75° of latitude, but by means of three determinations made by Mr. Scott- Hansen during the voyage, and a good many taken during the following years on the ice, it was possible to continue the curves and join the separated branches on a polar map. An inspection of the values of the deviation thus found showed that it could not be considered as constant for a given course during the whole voyage. On putting the deviation in the usual form A + B sin a + C cos a + D sin 2a + E cos 2a where a is the compass-course from north through east, the constants were determined separately for the following three periods, containing respectively 20, 22 and 26 observations (one of the 69 being omitted) taken between the limits given in the table below. Limits of rei. Date 1893 Lat. Long. Decl. I. /July 22 .... lAug. 9 .... 69°37' 71 20 41°55' E 66 44 10° E 20 II. /Aug. 11 .... \Aug. 28 .... 72 11 76 54 6825 95 2 23 29 III. /Sept. 7 .... \Sept. 22 .... 73 52 7850 100 40 137 8 28 7 On solving the equations by the method of least squares the observations of period II proved insufficient to determine the quadrantal deviation, most of the observations having been taken in the first and the adjoining part of LVI GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. the fourth quadrant, but only 4 in the second and none in the third. On putting the constants D and E for thia period equal to the mean of the values found for periods I and III, the following values were calculated and tables formed from them : A B C D E I. — 1.°72 -0.°98 + 5.°68 +3.°46 -O.°10 II. + 1. 16 -0. 84. + 10. 40 +2. 20 -1. 13 III. +3. 51 -3. 47 + 11. 13 +0. % -2. 15 Another difficulty in the determination of the situation of new islands etc. arose from the necessity of using dead reckoning. Owing to the difficult navigation, frequently hindered by fog or ice and often conducted between unknown banks and islands and in strong currents, the dead reckoning was often seriously in error, especially in longitude. The difference of east longi- tude found by dead reckoning being almost invariably too great, it was neces- sary to introduce a proportional reduction, which of course gives rise to some uncertainty when the interval from the nearest astronomical observation was considerable. Apart from some days spent in harbour there were, however, only few days without astronomical observations. On one occasion the difference of east longitude deduced from the astro- nomical observations was considerably in excess over that of the dead recko- ning, viz. on 1893 August 29 when the ship had encountered dead water in the afternoon and arrived in the evening at the ice border near Cape Laptev. This would seem to indicate an easterly motion of the fresh water forming the upper layer, relatively to the sea below through which the bulk of the ship was going, thus making the speed only apparently so small as given in the log book (for the last hours 1 or 2 knots with calm weather and the engine going full speed). In sailors' parlance it looks as if the ship was dragging some miles of sea with her. But other observations show that such a cur- rent would not suffice as a sole cause, and both Mr. Nansen and Mr. Scott- Hansen are of opinion that the dead reckoning under these circumstances is not sufficiently trustworthy to form the basis of an explanation of this curious phenomenon. NO. 6.] INTRODUCTION. VOYAGE ALONG THE COAST OF SIBERIA. LVII The present volume contains all astronomical observations made at sea between the departure from Vardo and the enclosure in the ice in 1893, but their application to the determination of the position of new islands etc. will be given in another volume. The Sledge Expedition. After a preliminary trial in the last days of February and the first days of March NANSEN and JOHANSEN started northwards 1895 March 14, turned southwestwards April 8, and got the first glimpse of land on July 23. It is a matter of course that the observations during this expedition, where the principal work of the travellers was very often a struggle for life, and where the instruments had to be handled in temperatures down to —40° C with no other source of heat than the observer's own body, could not attain any high degree of accuracy. The instrumental equipment for astronomical observations were the small altazimuth, the pocket sextant, and the two small compasses mentioned before; a glass horizon for the sextant was only used once, the level having been found to be cracked later on. The altazimuth was mounted on three fixed brass plates with radial furrows on the upper side of its box, with the latter standing on the hard packed snow, which was found to give a sufficient stability. The observer had to lie on the ice. On comparing the readings of the vertical circle of the altazimuth during this expedition with those taken on board an apparent difference will be found; while Mr. Scott- Hansen always noted the degrees by the vernier to the left, Mr. Nansen used for the same purpose the vernier on the opposite side to the object glass. In this manner half the difference between the readings in the two positions of the instrument, the telescope being in both cases pointed to the same fixed object, will give the altitude. The horizontal point of the circle differed only some minutes from 90°. It should be mentioned that the lines ruled on glass, forming the cross wires in the focus, are rather broad, between 1' and 2'; while this introduces no difficulty for the observation of stars which can easily be set between the borders of the line, the Sun's limb must be set 8 LVIII GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. tangent to one of them, and when the edge used is apparently the same (e. g. the upper) in both positions, they are really different; thus the horizontal point of the circle will be different in the two positions, unless the semidia- meter is given a constant correction. In the mean the effect will of course be eliminated. Both the travellers carried pocket chronometers which will be designated in the following by I and II. The first, carried by Nansen, was marked "Johannsen 6455", the other, carried by Johansen, was denoted in the jour- nals of the From as ,,No. 19787"; it was Nansen's watch from the Green- land expedition. Both were carefully compared with chronometer Hohwti by Lieut. Scott-Hansen during several months before starting, and under varying conditions which differed, however, considerably from those of the sledge expedition. The mean daily rate of I on Mean Time during periods of a week or more varied between 3.89 and 5.82 fast, of II between 1.82 and 3.83 slow. During the days February 26 — March 6, including the first trial expedi- tion, the rate of II was — 2.842, and during the next eight days which were spent on board, it was — 2.835. Watch I was not compared with Hw on returning to the ship (Nansen returned on March 3, Johansen on March 4) but the mean rate during Febr. 26— March 14 was +5.80. The relative rate of I — II was thus +7.84. During the expedition it was more irregular, but on the average greater, about 10 — 13 seconds. Both watches appear to have been going faster, but I more than II. It happened several times that one of the watches ran down. Unfortu- nately it happened also once, when the working day of the men had been longer than that of the watches, that both ran down. The astronomical obser- vations between which the stopping occured (1895 April 12) were 5 days apart. As the weather was clear and the ice good, the dead reckoning for this inter- val will probably not be much in error; but the drift of the ice is of course unknown. There is, however, another difficulty which for a certain period of the expedition is more serious than the stopping of the watches. During the months of April and May all altitudes were measured with the sextant, and, with one exception, from the natural horizon. In the afternoon of April 2 a series of 6 altitudes was taken, the first three with glass horizon, the rest with natural horizon. The two sets give a difference of nearly ten minutes NO. 6.] INTRODUCTION. SLEDGE EXPEDITION. LIX in the clock error. It was first believed that the glass horizon had got out of adjustment after levelling; a comparison with the result of a series of 5 altitudes taken in the morning of April 4 seems, however, to indicate another explanation, viz. a constant error in the altitudes measured from the natural horizon, evidently due to irregular terrestrial refraction causing the correction for dip to be nearly as large positive as it should be negative under ordinary circumstances for the given height of the eye. On both days the sky was clear, the Sun above the horizon all day long, and the weather mostly calm, but the temperature of the air below —30° C. There is some probability that a similar anomaly may have taken place also an other occasions under the same meteorological conditions; but the assumption that the horizon has on all occasions been elevated to the same amount must necessarily be affected by a considerable uncertainty. The same phenomenon (to a smaller extent) made itself manifest later on at the winter hut though the temperature was then much higher. Considering that in the high latitudes reached during this expedition an error of 1' in an altitude measured near the prime vertical, that is to say under the most favorable conditions, gives an error of a minute of time in the clock correction, it will be understood that the determination of local time by the means at hand was no easy task. On two occasions Mr. Nansen took Lunar Distances, one on the ice, the other at the winter hut. After the stopping of the watches he was often on the look out for the Moon during the periods of her visibility, but could not perceive her with the naked eye on the pale sky with the strong reflection of light from the immense white surface of the ice, till August 10; and even then the Moon disappeared in the haze after the measuring of a single dis- tance. The cutting out of the tables of Lunar Distances from the English Nautical Almanac having been forgotten he had no other data for the Moon than the mean time and the declination for upper culmination at Greenwich, by which means the computation on the spot was of course rather difficult. The uncertainty of the Greenwich Time deduced from the Lunar Dis- tances is not much greater than that of the Local Time. An approximate determination of the longitude of the winter hut at Franz Joseph Land may also be obtained by a combination of Mr. Nansen's observations in 1896 on the way to Mr. JACKSON'S station at Cape Flora. The writer does not know LX GEELMUYDEN. ASTRONOMICAL OBSERV. [NORW. POL. EXP. No. 6.] the particulars of the determination of the longitude of this place; but in a letter from Professor SCHIAPARELLI he is kindly informed that according to a private letter from a member of the expedition of H. R. H. the DUKE OF THE ABRUZZI, which had an excellent equipment of instruments, Lieut. CAGNI had made a new determination of the longitude of Cape Flora and found a displace- ment of 10' towards the east, which is not of importance in this connection. The duke having left Arkhangel only 9 days before reaching Cape Flora, it is very likely that a good determination could be made by means of the chronometers. The two Charts, showing the track of the ship and of the sledge expedition, are constructed on the stereographical projection. The scale indicated on the charts is valid for latitude 81° 17', but the difference for other latitudes is nearly insensible. The magnetic declination, which is indicated by arrows in some places where they could be inserted without inconvenience, is mostly taken from the observa- tions by compass on the ice, but some values have also been furnished by Mr. STEEN from observations in the magnetic observatory. The writer is under obligation to Professor H. H. TURNER of Oxford who has had the great kindness to read a proof of this Introduction. In conclusion the writer cannot withhold an expression of admiration for the activity and ability with which the men of the Fram have — under most trying circumstances and in a great measure with instruments and by methods lying far outside their practice in former life — collected so many important scientific results. August, 1900. OBSERVATIONS A. Altitudes measured with the Altazimuths. Observer: Lieutenant Scott-Hamen, when not otherwise stated. The small instrument, which was but seldom used on board, is indicated by the circle-reading only to tenths of a minute. The date here given is astronomical, the hours being counted from Noon of a meridian not very different from that of Greenwich (the chronometer Hohwv, being about 40 minutes in advance of Gr. M. T.). Owing to the great eastern longitude of the ship during the most part of the voyage the civil date on board was very often greater by 1 than that here given. The position of the observer before the ocular is as a rule not stated in the original, but may be inferred from other considerations and is added here in the column "Oc." in order to facilitate the application of the level-correction. The level-reading is reproduced here as given in the original; the correction to the circle-reading is in the direction Right— Left, the sign of which may be concluded from the above remark. As to the approximate bearing of the star it may be remarked that when the circle- reading is between 270° and 360°, the object glass was to the right of the observer, standing before the ocular; when between O9 and 90° to the left. (In the case of the small instrument, whose zenith-point is about 180°, the corresponding limits are 909 — 180' for the right, and 180°— 270° for the left). The two columns of circle-reading correspond to the two microscopes (or verniers for the small instrument). For the great instrument each number of seconds is the mean of two or sometimes three readings, corresponding to adjacent divisions of the circle. The two last columns before "Remarks" give the comparisons between the chrono- meter Hw and the observer's watch, in some cases supplemented from the Journal of daily comparisons. See also explanation to List B (sextant-observations). GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 1893 Star Oc. Watch Vertical Circle Level Watch Hw-W. U'lll. h m - 0 tn 1 II h m m s Aug. 6 Sun L. L. N 3 445 101 38.5 36.8 — 21 12 — 0 33.9 ') n S 8 23 258 39 37 . — 21 2 — 0 35.5 Oct. 5 Polaris E 1 24 58.5 169 32.5 32.3 S 0.5 N 1.7 026 + 1 28.5 n W 45 38 190 23 20 N 0.7 S 1.2 Jupiter N 1 56 27.5 247 4.5 6 E 0.5 W 1.7 • S 2 7 46 113 28.0 27.5 E 0.2 E 2.5 2 59 + 1 28.7 a) Oct. 5 « Ursa; Maj W 23 54 11 218 24 24.5 N 1.1 S 13 22 44 + 1 36.5 " 6 J) E 0 8 65 141 26.5 20.0 S 0.6 N 1.6 Jupiter S 0 19 11 108 20.0 18.5 W 0.9 E 1.4 • N 26 18 251 22.0 17.0 W 2.0 E 0.3 1 31 + 1 37.7 Oct. 8 Vega N 0 59 7.3 133 485 45.0 E 0.4 W 2.0 0 31 + 1 38.5 )j S 1 13 1 226 56.2 54.0 W 2.5 W 0.2 •) Polaris W 1 27 10.3 190 38.2 34.5 N 0.35 S 2.0 ft E 4335.5 169 27.5 24.5 N 1.4 S 0.9 2 3 + 1 39.3 Oct. 12 a Ursee Maj. E 1 2 42 140 34 33.5 N 1.4 S 0.7 0 51 + 2 6.5 W 13 44 219 26.5 26.0 N 0.35 S 1.8 Vega S 1 4049 229 2.5 4.0 W 2.55 W 0.4 ') N 2 0 38 129 59.5 58.5 W 1.0 E 1.2 2 35 + 2 7.1 Oct. 17 « Ursse Maj. E 1 16 41 320 44 16.0 43 54.5 N 9.0 S 20.6 23 45 + 2 41.2 6) n W 34 49.2 39 8 41.0 8 40.0 N 13.0 S 16.5 Capella N 1 48 37.8 42 44 49.5 44 32.0 W13.4 E 16.1 S 2 2 29.3 317 57 0.5 56 36.5 W14.0 E 15.6 2 35 + 2 41.5 Oct. 18 rsae Maj. E 23 9 34.0 321 17 55.5 17 41.0 N 16.4 S 14.0 22 45 + 2 53.6 n W 23 22.6 38 53 11.0 52 51.0 N 18.3 S 12.1 Capella N 23 36 53.8 48 45 560 45 40.5 W14.8 E 16.0 S 50 51.9 311 51 36.0 51 28.5 E 14.7 W16.1 24 15 + 2 54.5 Oct. 23 rsee Maj. E 0 7 27.8 320 38 53.0 38 50-0 N 16.2 S 14.8 23 27 + 3 11.1 n W 19 21.2 39 22 40.0 22 23.5 S 12.2 N 18.8 Capella N 0 32 7.7 45 34 17.5 34 5.5 E 20.6 W10.0 D S 41 24 314 53 59.5 53 34.5 E 13.0 W17.1 25 8 + 3 11.5 Oct. 25 a Cygni W 21 17 37.8 326 26 50.5 26 28.0 S 18.8 N 11.5 20 52 + 3 23.5 8) E 28 6.7 33 28 15.0 27 565 N 15 S 15 « Persei N 21 45 2.2 44 3 11.5 3 24.5 E 11.2 W19.5 S 5334.5 316 20 24.5 20 18.0 E 14.4 W16.1 22 6 + 3 23.5 Oct. 27 a Cass. S 21 33 33.8 329 49 33.0 49 13.0 W16.0 E 15.0 20 50 + 3 34.5 n N 47 17.2 29 29 4.0 29 15.5 W16.5 E 15.0 « Cygni E 21 59 57.5 33 26 56.0 26 29.0 S 16.5 N 14.9 W 22 9 27 326 29 45.0 30 8.0 N 15 S 16 22 27 + 3 34.3 Oct. 29 a Ursee Maj. W 22 10 58.2 38 31 1.5 30 45.5 N 16.0 S 15.8 21 41 + 3 44.2 n E 22 28 321 17 26.0 17 55.5 S 16.5 N 15.3 Capella S 22 36 48.8 310 20 20.0 20 43.0 E 13.0 W19.0 N 46 17.5 49 14 54.0 14 27.0 E 16.7 W15.2 23 26 + 445.5 7) Oct. 31 e Cass. N 20 59 14.8 28 21 28.5 21 55.5 E 16.6 W15.5 20 26 + 3 55.8 f) S 21 7 47.0 332 3 13.5 3 53.0 W16.7 E 15.3 Deneb W 21 20 47.7 326 50 59.0 50 27.0 N 16.0 S 16.0 E 34 8 33 7 21.0 7 49.0 N 16.6 S 15.5 23 23 + 3 57.6 Nov. 2 e Cass. N 21 948.3 27 25 35.0 26 13.5 E 18.0 W15.5 20 23 + 4 10.5 8) S 4524 334 23 0.5 23 30.0 W16.5 E 17.3 a. Cygni W 22 5 12.5 326 39 38.0 39 10.0 N 18.0 S 15.5 E 17 50 33 31 41.0 31 6.5 S 19.6 N 14.0 22 36 + 4 13.5 Nov. 6 e Cass. N 21 8 16.3 26 5 49.0 5 0.5 E 14.0 W15.2 20 22 + 4 49.8 ff S 27 21.5 334 55 12.5 54 23.0 W13.5 E 16.5 « Cygni W 21 4324 326 44 38.0 45 23.0 S 17.5 N 12.8 E 5854 33 29 56.0 30 32.0 S 13 N 17.2 22 20 + 4 50.6 Nov. 9 e Cass. S 21 1 3 334 10 30.5 9 55.5 E 15 W14 12 48 + 5 12.0 n N 2241.7 24 43 12.0 42 28.0 E 14.5 W14.5 ») Comparison Aug. 5. 2) Level assumed W.-0.2. 8) Lev. E.-0.2. 4) Lev. E.-0.4. t>) Comp. Oct. 16. ") Level a little uncertain, as there was some motion in the ice. 7) Assumed Hw— W. = 3 45.5. *) Observer Johansen. NO. 6.] ALTITUDES MEASURED WITH THE ALTAZIMUTHS. 1803 Star Oc. Watch Vertical Circle Level Watch Hw-W. inn. h m s 0 ' « / It h m m s Nov. 9 a Cygni E 21 37 50 3327 6.0 27 51.0 S 15.5 N 13.5 • W 46 57 326 23 23.5 24 11.0 S 12.5 N 16.5 21 59 + 5 14.6 Nov. 12 e Cass. S 20 41 3.5 333 54 25.0 53 38.0 E 15.2 W16.0 19 43 + 5 35.5 n N 54 50 25 24 18.0 23 31.0 E 16.3 W14.9 « Cygni E 21 10 4.3 33 21 11.0 21 55.0 S 15.5 N 15.5 H W 29 54 326 21 18.0 22 0.0 N 17.1 S 13.3 21 57 + 5 36.5 Nov. 16 e Cass. N 20 53 28.8 24 27 9.0 26 24.0 E 15.4 W15.5 19 33 + 6 5.5 ft S 21 4 21.5 336 6 33.5 5 45.0 E 17.0 W14 « Cygni W 21 18 28 325 51 7.5 51 40.5 S 17.2 N 13.2 ft E 27 10 34 19 26.0 18 51.0 S 15.7 N 15.2 22 12 + 6 6.1 Nov20 e Cass. N 20 54 10.2 23 33 59 34 [44 E 15.5 W17.4 19 56 + 646.5 n S 21 15 3 337 28 28 28 57.5 E 15.4 W17.5 « Cygni W 21 35 32 325 5 50 6 37 S 13.0 N20.0 • E 48 3.5 35 16 13 15 25 S 20.2 N 12.7 22 26 + 648.2 Dec. 4 t Cass. N 20 9 542 23 15 17 16 ' 2 E 17.0 W16.5 19 9 + 8 57.2 ') S 41 54.0 338 25 45 24 53 E 16.5 W17.5 2) rs« Maj. E 21 4 6.0 321 12 31 13 25 N 14.7 S 19.5 n W 19 22.5 38 48 30.5 49 7.5 N 16.0 S 18.0 21 46 + 8 57.8 Dec. 8 e CilSS. N 20 5 55.0 23 11 41 12 6.5 E 18.0 W14.9 1851 + 0 14.0 S 16 33.5 337 19 28.5 19 6.5 E 16.0 W17.0 rsie Muj. E 20 31 31 321 26 55.5 27 33 S 19.1 N 13.5 n W 45 30 38 37 24.5 37 54 N 16.1 S 16.4 21 17 + 0 14.5 Dec. 11 e Cass. S 20 10 1 337 35 15 34 44 E 16.2 W16.0 1934 + 0 37.B N 2259 21 49 1 49 34.5 E 15.1 W17.2 n Ursa; Maj. E 20 42 26 321 29 38.5 29 10 N 17.0 S 15.6 • W 55 32.5 38 32 59.5 32 27.5 N 16.9 S 15.5 21 34 -f 038.2 Dec. 17 f Cass. S 19 5 18.5 25 40 52.5 40 26 W16.0 E 13.9 18 18 + 1 30.0 3) M N 14 1.2 23 55 14 54 29.5 E 17.3 W13.5 n Ursae Maj. W 19 34 2.2 38 14 56.5 15 38 N 15.3 S 15.3 • E 52 31.0 321 34 51 35 30.5 N 15.0 S 15.6 20 26 + 1 30.6 ') Dec. 19 e Cass. S 18 44 17.5 335 3 0 2 31.3 E 15.4 W16.1 18 17 -f 1 51.5 N 55 4 25 27 16.5 26 36 E 15.0 W17.5 4) rsae Maj. W 19 5 58.7 37 59 0.5 59 31 N 16.4 S 16.8 n E 12 32 321 55 13.5 55 55 N 18.4 S 15.2 19 38 + 1 52.0 Dec. 21 / Cass. N 19 45 20 22 12 13.5 11 52 E 17.0 W15.3 19 17 •f 2 10.2 B) • S 5428 338 8 38 8 23.5 E 18.0 W14.5 £ Cygni W 20 9 55 312 45 5.5 45 33.5 S 16.2 N 16.9 ") n E 26 24.0 47 42 55.5 43 15.0 N 15.0 S 17.6 2049 + 2 11.0 Dec 23 £ Cass. S 18 48 9.4 335 56 29 55 57.5 E 16.5 W15.0 1825 + 2 24.5 N 19 1 4 23 27 20 26 47.5 E 16.5 W16.9 rsse Maj W 19 9 20.0 38 12 5 12 36.5 N 150 S 18.6 n E 16 3.5 321 43 45 44 15 N 15.1 S 19.0 1940 + 2 25.0 Dec. 26 « Persei S 20 30 53 324 9 8 8 51 E 18.8 W13.1 19 58 — 1 11.5 N 39 1.5 35 28 50 29 15 E 17.0 W15.0 a Ursse Maj. W 204832 38 30 38 30 55.5 N 15.2 S 16.8 ft E 56 25 321 32 26 32 57 S 15.5 N 16.5 21 24 — 1 11.0 Dec. 28 « Cass. N 185335 22 59 50 59 37 E 15.0 W15.3 18 25 - 0 54.5 • S 19 1 23.5 337 22 39 22 18 E 14.4 W17.0 a UrssE Maj. E 19 9 24 321 29 2 28 34.5 N 11.2 S 20.4 n W 16 21.5 38 34 56.5 34 25 N 15.1 S 16.9 19 32 - 0 54.0 Dec. 30 •• Cass. S 18 59 42 337 35 23.5 34 54.5 E 13.9 W16.1 18 44 — 038.8 N 19 7 59 22 1 40.5 1 19 E 16.0 W16.0 &i rsa: Maj. W 19 15 3 38 a-; 40 35 3.5 N 20.0 S 12.7 n E 21 36.5 321 23 18.5 22 54.5 S 17.2 N 16.0 19 34 — 036.7 1894 Jan. 1 e Cass. N 19 18 58 21 6 51.5 6 11.5 E 1R7 W13.9 1853 - 0 24.0 » S 26 13.0 339 13 11 13 37 E 16.0 W17.8 *) Observer Johansen. 2) Ass. corr. to circle — 10". 6) Hazy. 6) Star ass. « Cygni. 8) Circle ass. 335°. 4) Circle ass. GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 1894 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. ll III S 0 ' <> / U h in m s Jan. 1 a Ursa? Maj. E 19 45 58.5 321 16 39.5 15 55.5 N 17.5 S 17.5 •n W 5443 38 43 39.5 43 4.5 N 17.0 S 18.0 20 11 — 0240 Jan. 4 s Cass. S 1855 31 338 25 53.5 25 11 E 16.5 W17.0 1830 0 0.0 • N 19 4 12 21 1055 10 36 W16.3 E 18.0 « Ursue Maj. W 19 12 23 38 41 37.5 41 11 N 17.3 S 17.3 n E 21 0 321 17 47 17 19 N 16.9 S 18.0 19 38 + 0 0.5 Jan. 7 f Cass. S 19 11 17.7 339 40 26 40 6.5 E 16.7 W17.3 18 45 + 023.5 N 18 5.0 20 3 0.5 2 24 E 18.3 W16.3 rare Maj W 19 27 4.0 38 35 16 34 35.5 N 18.2 S 16.7 E 38 12.0 321 27 0.5 26 10.5 N 16.5 S 18.5 20 14 + 0 24.0 Jan. 9 rsse Maj. W 19 57 35.1 3823 15 22 41 N 15.5 S 17.5 19 20 + 038.1 ') • E 20 12 37.5 321 44 53.5 44 12.5 N 18.5 S 15.5 S Draconis N 2029 48 337 37 11 36 22 E 19.0 W16.5 yi S 3852.5 22 4850 48 22 W194 E 16.2 20 55 + 039.0 Jan. 12 y Draconis N 19 54 18.0 320 17 18.5 17 50.5 W16.0 E 16.6 19 17 + 1 0.9 • S 20 1 31.6 40 2 43 2 14 E 162 W17.0 « Ursa; Maj. W 20 11 45 37 60 3 59 35 S 17.0 N 16.5 E 20 14 322 6 34 7 17.5 N 18.1 S 15.6 2037 + 1 1.5 Jan. 15 rsffi Maj. E 18 46 14.5 321 36 22.5 35 32.5 S 17.7 N 14.8 18 25 + 1 29.6 n W 52 30 38 24 40 23 55 S 18.3 N 15.1 7 Draconis S 18 59 58.5 37 47 59 48 45.5 W21.2 E 13.2 t* N 19 9 7 321 46 15 47 2 E 18.5 W15.9 19 35 + 1 30.0 Jnn. 18 y Draconis N 18 59 30 321 46 29 45 52.5 E 164 W16.3 1830 + 1 58.0 S 19 9 11 38 40 17.5 40 43 W18.0 E 13.8 20 20 + 1 58.8 2) Jan 21 rsae Maj E 18 21 51 322 036 0 14 N 16 1 S 15.9 17 57 + 2 26.5 n W 29 26.5 38 0 18.5 0 0 N 17.1 S 14.7 2) a Cygni N 22 52 27.5 312 2 12.5 2 48-5 W149 E 16.6 M S 23 0 4 48 17 11 16 31.5 W16.5 E 14.7 2329 + 2 29.5 Jan. 22 « Cass. W 19 42 21 336 12 37.5 13 20 S 17.1 N 16.7 17 45 + 2 35.8 n E 51 27 23 45 29 44 48 S 19.0 N 15.0 « Ccpbei S 20 443.5 22 38 19-5 37 51 W18.0 E 16.0 y N 13465 336 59 3.5 59 31 W11.9 E 17.1 2038 + 2 37.0 Jan. 25 e Ursa; Maj. E 20 5 7 316 17 29.5 16 505 N 17 4 S 18.0 19 38 + 3 5.0 « W 1438 43 43 15 42 38 N 193 S 15.8 « Cephci S 20 22 25 23 51 54.5 52 30.5 W19.0 E 15.6 N 29 47.5 3354844 49 13.5 E 19.0 W16.0 2048 + 3 5.3 Jan. 27 rssc Maj. E 18 49 51.5 322 12 49 13 35 N 17.0 S 18.6 18 38 + 3 24.2 n W 19 6 0 37 40 52-5 40 20 N 20.7 S 14.0 7 Draconis S 19 13 52 40 440 3 55 W17.5 E 16.9 N 22 46 319 32 54.5 33 44.5 W17.0 E 17.4 19 40 + 3 24.5 Jan. 29 rsa; Maj. E 1840 6 322 13 22 12 53 N 16.1 S 17.9 18 18 + 344.4 j* W 47 56 37 4426 43 50 N 17.6 S 16.4 X Draconis S 18 57 12 39 42 45.5 42 9.5 W18.1 E 15.5 n N 19 456 319 57 57.5 58 30.5 E 18.6 W15.0 1930 + 3 450 Feb. 1 Vega W 14 3 22 31832 35 33 11 N 17.2 S 14.0 13 36 + 4 11.5 n E 9 37.5 41 30 57.5 31 20 N 16.2 S 14.8 « Cass. N 14 2247 32 50 53 51 20.5 E 14.8 W16.2 S 33 59 327 35 53.5 35 12 W13.0 E 18.0 14 50 + 4 12.0 Feb. 4 rsro Maj E 18 36 48 322 33 54 34 49.5 N 20.0 S 16.6 18 13 + 4 44.8 • W 4443.5 37 21 52.5 21 8 N 18.3 S 18.3 y Draconis S 18 51 33 40 26 3 26 50.5 W16.4 E 18.7 • N 19 0 51 319 11 4.5 10 16 W18.0 E 18.6 1923 + 445.7 Feb. 8 Vega N 19 33 19.5 306 15 54 15 17.5 W15.6 E 13.0 18 19 + 5 21.5 jl S 4029 54 2 10 2 41 E 16.0 W13.5 a Cass. E 19 4835 2420 4 20 34.5 S 15.1 N 15.1 « W 5525 3353431 33 55 N 18.0 S 13.0 20 10 + 5 22.0 ') Observer Johansen. Cloudy. NO. «.] ALTITUDES MEASURED WITH THE ALTAZIMUTHS. 1894 Star Oc. Watch Vertical Circle Level Watch Hw— W. Rem. h "m s 0 ' <• / II h m m s Feb. 11 o Cephei N 19 30 13.5 335 27 5.5 26 19.5 W15.4 E 20.2 19 8 + 5 50.0 n S 37 39 24 53 205 52 43 W20.1 E 15.5 Polaris w 19 49 47 8 44 38.5 45 22 N 19.0 S 16.9 n E 58 32 351 15 23 14 45 S 19.5 N 16.2 2033 + 5 50.5 Feb. 13 Polaris E 19 35 48 351 15 30 14 58.5 N 18.0 S 16.6 1855 + 6 11.5 ft W 42 6 8 45 15 44 38 N 16.0 S 19.0 a Cephei S 19 59 41 26 6 20.5 5 41.5 W195 E 15.7 n N 20 22 7 332 55 18 55 54 W16.2 E 18.5 22 23 + 6 13.0 Feb. 19 o Cephei N 21 3 35 330 9 33.5 9 9 W15.3 E 18.3 20 40 + 7 10.7 • S 10 1.0 30 5 55 6 38.5 W16.0 E 18.0 i) /? Ursffi Min. E 21 19 5 33448 30 48 14.5 S 19.5 N 14.5 / li W 26 31.5 25 9 29 9 7 N 16.0 S 18.0 21 45 + 7 11.5 Feb. 21 Capella W 21 29 55 325 12 8 12 29.5 N 15.0 S 15.3 2039 + 7 27.7 n E 41 48.5 3437 57 37 33.5 N 15.1 S 15.0 n E 22 10 52 34 21 14.5 20 57.5 S 16.0 N 14.3 n W 17 30 325 41 28.5 41 135 S 17.4 N 13.0 2348 + 7 29.0 Feb. 22 a Cass. N 025 39 323 52 9 51 50 W15.5 E 18.0 n S 34 5 36 28 52.5 28 39.5 W16.0 E 16.6 1 3 + 7 29.9 a) Feb. 23 a Cephei N 21 1 2 329337 34.5 36 46.5 E 18.9 W16.5 2035 + 7 43.1 / ft S 9 19 3033 23 32 32 W16.9 E 18.4 8) Capella E 21 39 32 34 29 27.5 28 46.5 S 18.6 N 15.6 / n W 49 27 325 37 12.5 37 57.5 N 18.2 S 16.7 22 1 + 7 44.0 Feb. 26 Capella W 2253 20 325 37 22 37 41.5 N 15.0 S 15.7 22 23 + 8 12.7 n E 23 0 10 34 26 22 26 45.5 N 15.7 S 15.0 a Cass. S 23 13 1.5 34 17 0.5 16 32 W16.0 E 15.0 n N 1941 325 26 17.5 25 48 W17.0 E 16.0 23 36 + 8 13.3 Mar. 3 y Draconis E 22 51 12 311 27 21 26 8.5 N 18.6 S 16.0 22 35 — 0 3.5 • W 56 32.5 48 33 30.5 33 59.5 N iae s 16.0 a. Ursse Maj N 23 3 9 26 15 20 14 19.5 W20.4 E 14.3 • S 9 39 334 339 2 35 W19.0 E 15.0 23 25 — 0 3.0 Mar. 5 a Lyra? E 23 1031 118 6-5 2.5 N 1.0 S 2.0 13 25 + 0 12.3 W 18 13 240 55.0 55.5 N 0.7 S 2.2 y Ursa? Maj. N 23 31 54 213 55.0 53.0 W 0.6 E 2.3 |) S 39 26 145 27.5 24.5 W 0.3 E 2.6 24 15 + 0 17.0 «) Mar. 10 a Cygni W 0 23 5 235 12 10 N 1.5 S 1.4 23 52 + 0 59.0 B) n E 29 28 12444.7 40.5 N 2.0 S 1.0 a Persei N 0 36 24.5 141 24.5 20.5 W 2.2 E 0.7 n S 43 2 218 52.5 51-0 W 1.6 E 1.3 13 24 + 1 5.0 Mar. 13 a Persei S 0 22 36 218 25.5 24.5 W 1.3 E 1.6 1328 + 1 25.0 ") n N 29 11 141 155 10.0 W 2.5 E 0.3 a Cygni E 03929 124 33.5 30.5 N 1.8 S 1.0 d W 46 32 235 23.5 20.5 N 1.4 S 1.5 1 1 + 1 28.5 Mar. 15 a Persei N 0 19 0 321 20 6 19 13.5 W16.0 E 19.2 23 53 + 1 47.0 *) n S 26 59 39 3 0.5 2 2 W17.0 E 18.2 a Cygni W 0 33 26 55 25 57.5 25 5.5 N 18.0 S 17.2 n E 4055 304 34 53.5 33 52.5 N 16.7 S 19.0 1 1 + 1 475 Mar. 18 a Cygni E 21 51 1 304 42 0.5 41 8.5 N 19.3 S 16.6 j» W 58 11.5 55 2054 21 47 N 17.6 S 18.3 o Persei S 22 7 48 3858 14 57 17 W17.6 E 183 n N 17 7 320 37 36.5 36 41 W18.7 E 17.0 2234 + 12235.0 Mar. 22 o Persei N 23 58 40 319 38 37.5 37 40.5 W18.0 E 16.0 2324 + 0 19.2 8) 23 n S 0 13 16 4050 35 49 42 E 19.5 W14.4 *) a Cephei W 0 31 47 37 48 1 48 58 N 17.4 S 16.7 M E 4026 322 11 11 10 11 N 15.4 S 18.8 1 23 + 0 20.0 Mar. 26 « Persei N 033 320 12 39.5 11 54.5 W20.4 E 14.6 23 27 + 0 495 10) n S 8 2.5 40 052 1 32 W19.0 E 15.7 ') Some motion in the level. -) Cloudy, stars often invisible. 8) Ass. corr. to circle + W- 4) Zenith-point about 179° 30'. B) Comp. March 9. «) Comp. March 12. ') Comp March 14. 8) Ass. corn to circle + 1° 10'. 8) Ass. corr. to circle — 1°. 10) Comp. March 25. 8 GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 1894 Star Oc. Watch Vertical Circle Level Watch Hw-W. iem. h m s 0 ' " * U h m m s Mar. 26 a Cephei W 0 15 0 37 45435 46 42 N 19.0 S 15.7 E 21 37.5 322 13 11 12 24.5 N 17.5 S 17.1 0 33 + 0 49.8 Mar. 31 a Persei N 0 036 319 24 51.5 24 7 W18.0 E 15.2 23 31 + 1 39.7 i jt S 10 4 40 59 21 60 1 W14.3 E 19.0 13 2 + 1 46.0 2 Apr. 6 y Draconis S 2 56 0.5 321 24 32 23 53 E 14.0 W19.7 19 32 + 2 37.7 8 N 3 1 35 38 22 32 22 2.5 E 18.0 W15.7 a Cass. W 3 8 14 43 4846 48 325 N 18.0 S 15.6 E 13 5 316 12 0 11 34 N 14.9 S 18.7 3 25 + 2 40.5 May 4 Su\i U. L. N 21 58 14 286 1 29.5 1 31.5 W 8.7 E 15.8 13 16 + 7 36.5 T) S 22 3 44.5 74 12 0.5 11 49.5 W14.0 E 12.0 22 28 + 7 40.0 May 25 Sun L. L. W 144545 298 32 50 32 22.5 S 10.6 N 12.5 13 47 + 2 7.0 • E 51 48.3 61 21 39.5 21 21 S 10.5 N 12.7 Sun U. L. N 21 39 26 291 5 46 5 19 W14.0 E 8.8 20 55 + 5024.5 4) S 46 58 69 9 55.7 9 45 W12.0 E 11.0 22 3 + 5025.0 June 3 Sun L. L. S 13 14 24.7 297 33 32.5 33 15.5 E 12.4 Wll.4 N 1834 62 19 15.5 18 59 E 12.2 Wll.6 13 42 — 0 17.8 June 4 Sun L. L. N 12 37 29.5 63 28 4.5 27 55.5 E 9.0 W14.0 12 2 — 0 9.0 S 42 11.5 296 4052 40 53 E 10.4 W12.8 14 0 — 0 8.2 June 6 Sun L. L. S 12 25 23.5 296 22 31 22 17.5 E 12.1 W 7.0 11 53 + 0 34.3 4 N 12 32 20.5 63 24 0 23 42 E 11.7 W 8.8 13 56 + 0 35.0 Sun U. L. N 22 31 56 292 46 17 46 31.5 W10.0 E 11.8 S 37 36 67 25 51 25 31.5 W12.7 E 9.5 22 55 + 0 38.7 June 7 Sun L. L. S 13 16 38 298 458 4 30 E 5.0 W16.0 N 21 30 61 46 46.5 46 29 E 8.6 W12.3 13 55 + 0 44.2 June 12 Sun L. L S 13 30 11 298 37 59 37 45.5 E 10.4 W10.4 E 35 15.5 61 13 57.5 13 38.5 S 10.8 N 9.9 1346 + 1 25.5 Sun U. L. N 21 47 29 294 49 57 49 49.5 W 9.0 E 12.0 S 53 53 65 23 54-5 23 35.5 Wll.O E 10.3 22 6 + 1 27.5 5) Ju. (16) Sun U. L. W Noon 301 46 43.2 46 26.5 N 11.0 S 8.1 Terr. Obj. S — 270 17 44-3 17 52 E 10.2 W 9.3 N 89 41 44-7 41 42.3 E 105 W 9.1 June 22 Sun L. L. S 13 22 57 298 35 47.5 35 32.5 E 9.4 Wll.O 11 54 + 2 42.5 N 27 46.5 61 16 5.5 15 50 E 13.3 W 6.9 14 1 + .2 42.5 July 5 Sun L. L. S 12 29 36.8 297 13 23 13 1 E 14.8 W 6.1 U 57 + 438.1 Terr. Obj. N — 270 14 26.5 14 22 E 15.6 W 6.5 S • — 89 44 54 44 36 E 10.5 Wll.4 July 10 Sun L. L. S 12 37 13 296 31 48 31 57.5 E 8.7 Wll.6 11 54 + 5 23.0 N 41 23.4 63 19 51 19 48.5 E 9.9 W10.8 13 55 + 5 24.0 July 14 Sun U. L. N 1 28 15.6 285 41 38 41 29.5 E 4.6 W15.7 13 55 + 5 51.2 6 S 33 31.4 74 25 2 24 45 W a4 E 12.1 I 59 + 556.5 July 27 Sun U. L. N 21 35 47.5 290 3434 34 51 W 7.9 E 14.9 21 13 + 7 55.5 S 40 45 69 36 29 36 7.5 W10.4 E 11.5 25 4 + 7 57.7 Aug.25 Sun L- L. S 14 3450 288 2655.5 26 25 E 13.5 W 9.7 1356 + 1 25.2 N 40 15.5 71 27 16.5 27 41 E 11.0 W12.0 1457 + 1 25.5 ') Sun U. L. N 21 2 54 283 13 9.5 12 45 W12.0 E 11.0 S 1027.2 77 422.5 3 54 W12.9 E 10.2 22 38 + 1 28.3 Sep. 3 Sun U. L. S 12 46 48.8 282 42 13 41 47.5 E 16.3 W 7.3 11 52 + 2 51.3 "-"T N 51 59 77 8 18 7 55 E 13.0 Wll.4 13 34 + 2 52.0 Sun U. L. N 2057 56 280 36 49-5 36 19 W11.7 E 12.1 S 21 3 17.6 79 34 50.5 34 19 W12.0 E 11.3 22 7 + 2 57.0 Sep. 12 Sun U. L. S 12 59 24.8 279 20 5.7 19 25 E 9.2 W14.8 12 31 + 4 32.5 r N 13 7 27.4 79 57 12.7 56 21 E 10.2 W10.2 13 55 + 4 32.2 Sep. 15 a Ursie Maj W 3 55 56.7 36 20 39.5 19 56 N 12.8 S 13.1 13 56 + 0 75 ") E 4 3 36.4 323 41 18.5 40 19.5 N 14.1 S 12.7 y Draconis N 4 14 54 321 44 55 43 15.5 W15.5 E 12.0 9 / S 21 28 38 31 9.5 32 0.5 W15.0 E 13.0 « Lyrae S 4 25 26.8 49 52 15 51 28 W17.6 E 10.5 5 4 + 0 14.7 >) Comp. March 30. 2) Cloudy. 3) Comp. April 5. *) Watch had stopped shortly be- fore. 5) Ice-pillar loosened, but instrument steady during the observation. B) Comp. July 13. 7) Image not sharp. 8) Comp. Sept. 14. 9) Must be another star. NO. 6.] ALTITUDES MEASURED WITH THE ALTAZIMUTHS. 1804 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. h m s 0 ' » / II h m m s Sep. 17 • > + 9 4.5 Nov. 7 a Cygni W 22 49 49 322 45 43.5 4447.5 S 16.0 N 18.0 22 25 + 9 37.0 • E 55 55 37 16 45.5 1543.5 S 17.7 N 16.6 s Gass. N 23 6 4.5 25 5 22.5 4 26.5 E 17.8 W16.6 m S 12 42.0 335 8 33.5 7 37.5 E 16.8 W17.4 23 37 + 9 38.0 Nov. 10 •/ Draconis N 0 53 2.5 322 34 59.5 33 56.5 W17.0 E 17.7 0 32 +10 4.0 M S 57 30.7 37 36 5 37 11.5 W17.2 E 17.2 a Ursae Maj. W 1 5 34.0 35 27 4.5 28 0.5 N 18.7 S 15.2 n E li 50.7 324 33 57.5 32 59 N 16.5 S 18.0 1 58 +10 4.9 Nov. 12 n Cygni W 22 34 58.5 322 46 24.5 45 20 S 18.5 N 16.4 22 9 + 10 36.8 E 40 42.5 37 15 48 1448 S 17.2 N 18.0 « Persei N 22 47 42.3 41 25 0 24 5 E 17.0 W18.4 S 53 59.5 318 48 19 47 23.5 E 17.9 W17.6 23 21 +10 37.8 Nov. 17 a Lyrae S 1 45 44.5 50 48 25 47 43 E 15.0 W14.6 0 55 +11 21.7 ') N 31 7.0 309 1 21 0 30 E 16.6 W12.6 a Cass. W 1 36 39.5 333 51 31 50 50 N 15.0 S 15.0 W E 42 13.0 26 8 18 7 30 N 15.0 S 15.0 1 55 +11 22.5 Nov. 21 /? Ursae Min. W 16 4 0 352 31 47 31 10.5 S 14.0 N 15.9 1437 + 12 16.5 u E 12 22 7 32 25 31 41.5 S 12.0 N 18.2 « Cygni N 16 21 51 43 55 45 54 52 W16.3 E 14.4 n S 27 58 316 17 28 1634 E 14.4 W16.6 2035 + 12 19.2 « Cephoi W 22 25 55 340 7 59.5 6 54 S 14.0 N 18.3 E 31 38 19 54 21 53 14 N 16.5 S 16.3 a Persei N 2238 54 40 11 44 10 57.5 E 16.7 W16.3 n S 45 13 320 2 39 1 45.5 E 16.5 W16.3 23 27 +12 21.7 2) Nov. 24 /? AurigoD S 1 12 55.6 315 36 17.5 3525 E 16.2 W15.2 0 58 +12 50.5 n N 17 8.2 44 15 27 14 28.5 W15.0 E 16.7 « Cass. E 1 23 7.8 25 59 56.5 59 7.5 S 16.0 N 15.6 n W 28 38 333 60 49 59 58.5 S 15.6 N 16.2 1 56 +12 51.5 Nov. 26 n Persei S 22 57 20 321 4 29.5 3 35 E 17.0 W17.1 22 17 +13 24.5 N 23 3 11 38 44 23 4335 E 17.0 W16.91 a Ursoe Maj. W 23 8 1.5 35 28 25 29 24 N 17.3 S 17.0 E 13 10 324 30 46 29 52.5 N 16.0 S 18.1 14 21 +13 33.6 ") Nov. 28 « Ursae Maj. E 22 45 28 324 36 18 35 8 N 17.0 S 17.5 14 20 + 13 43.7 W 49 23.6 S5 25 51 2445 N 17.9 S 16.7 y Draconis S 22 55 0.4 36 8 0.5 7 3 W17.7 E 16.8 n N 23 0 39 323 41 52 40 44.5 W18.0 E 16.5 23 20 + 13 48.2 ') Watch assumed 25m. 3) Comp. Nov. 27. 2) Two sets of observations, our ice-island having loosened. NO. 6.] ALTITUDES MEASURED WITH THE ALTAZIMUTHS. 11 1894 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. h m s 0 ' " . 11 h m m s Nov. 30 « Persei s 22 47 42.5 321 11 50 1045 E 17.0 W17.4 22 34 + 14 9.0 N 52 16 3840 11 39 23.5 E 16.7 W17.4 a Ursee Maj. W 22 56 41.4 35 2854.5 27 54.5 N 19.0 S 15.1 • E 23 1 53.6 324 31 35 30 30 S 17.0 N 17.3 23 13 + 14 9.3 Dec. 3 a Persei S 22 35 27 321 5 13 4 7 W14.8 E 19.0 22 16 + 14 41.0 ft N 40 23 38 43 46 42 41 E 16.5 W17.8II « Cephei E 22 47 47.5 2040 52 3948.5 S 17.0 N 17.4 W 53 2* 339 15 11 14 5.5 S 15.0 N 19.3 1421 +14 49.0 ') Dec. 5 a Urste Maj. E 22 52 40 324 40 57.5 39 56 N 16.3 S 17.0 22 27 +15 2.2 W 23 1 2.5 3520 58 1949 N 17.0 S 16.7 7 Draconis S 23 5 4.5 37 14 29 13 12.5 W16.0 E 17.5 • N 10 35 322 35 33 34 27 E 17.0 W16.6 23 22 +15 3.0 Dec. 7 a Ursae Maj. E 22 32 47.5 324 43 32.5 42 25 N 16.5 S 18.6 22 17 +15 22.8 ft W 3820.5 35 18 52 17 34.5 S 17.4 N 18.0 •/ Draconis S 22 44 47 36 46 42 4527 W19.0 E 16.1 N 51 46 322 60 34.5 59 31.5 W19.5 E 16.0 23 16 +15 24.2 Dec. 11 rsee Maj. E 22 35 26.7 32451 1 50 6 N 15.6 S 16.5 22 10 +16 3.5 2) n W 42 17.2 35 10 11.5 9 19.5 N 15.5 S 16.5 a Aurigae N 22 52 46 44 41 27.5 40 35.5 E 19.8 W12.4 S 59 19 315 32 53 31 55 E 14.4 W17.6 23 25 +16 4.2 Dec. 14 rsae Maj. E 22 36 35 324 54 2 52 56.5 N 16.0 S 17.6 22 13 +16 35.0 W 41 26 35 6 46.5 5 42.5 N 15.0 S 18.6 7 jDraconis S 2246 24 37 38 50.5 37 57.5 W15.4 E 18.3 N 5241 322 9 49.5 8 54 W16.2 E 17.5 2331 +16 36.5 Dec. 16 rsee Maj. E 223850 325 10 24.5 9 10.5 N 17.5 S 18.0 22 9 + 16 56.7 W 4438.4 34 50 45 4930 N 18.7 S 16.9 7 Draconis S 22 50 9 37 49 4.5 48 8.5 W19.0 E 16.3 N 57 8 321 59 16 58 5.5 E 18.7 W16.9 23 17 +16 58.0 Dec. 18 rsiB Maj. E 23 2 38 325 14 32.5 13 21 N 15.7 S 19.6 22 42 +17 19.0 W 8 8.4 344538 44 28 N 18.0 S 17.1 / Draconis S 23 17 54.2 33847 46 46 48 W16.6 E 18.6 8) M N 23 15 21 3 31.5 2 19 W16.6 E 18.6 24 13 +17 20.8 ') Dec. 21 a Cass. W 1 47 57.5 3325354 52 46.5 S 16.9 N 19.0 0 24 + 17 42.8 6) n E 53 11 27 10 23 9 17.5 S 19.0 N 16.6 6) ft Aurigae N 1 2 23 42 19 2.5 18 0.5 W18.0 E 17.7 • S 9 0 317 53 55.5 52 48 E 16.5 W19.2 1 35 + 17 43.5 Dec. 24 7 Draconis W 16 0 15 327 29 14.5 28 34 S 16.8 N 15.0 15 10 - 2 0.5 6) a Ursae Maj. N 16 52 20 331 11 46.5 11 7 E 17.0 W15.2 Capella W 17 12 8 5039 40.5 39 11.5 N 15.6 S 16.6 E 18 20 30921 43 21 10 N 15.6 S 16.6 17 39 - 1 59.0 rsse Maj. E 21 58 16 325 38 16.5 37 31 N 17.4 S 15.5 21 49 - 1 57.5 7) W 22 5 9 34 13 52 12 58.5 N 17.0 S 16.2 •/ Draconis S 22 11 27.5 36 36 33 35 26.5 W14.0 E 19.0 N 1847 323 11 54.5 11 5.5 W14.5 E 19.0 22 29 - 1 57.5 Dec. 26 a Ursae Maj. E 22 18 8 325 42 44 41 41 N 17.0 S 17.0 22 1 - 1 38.5 W 24 44 34 19 7.5 18 9.5 N 17.0 S 16.7 7 Draconis S 223333 37 33 22 32 20 W17.0 E 16.7 N 41 10 322 24 44 2346.5 E 17.0 W17.0 23 1 - 1 37.7 8) Dec. 28 « Ursa? Maj. E 22 46 16-4 325 40 56 40 11.5 N 15.0 S 17.0 15 9 - 1 17.8 W 52 12 34 18 42.5 17 54 N 14.2 S 18.0 / Draconis S 23 021 38 30 31.5 29 40.5 W17.8 E 17.4 N 520 321 22 6 21 7.5 W15.0 E 17.0 23 47 - 1 15.0 Dec. 30 « Ursae Maj. E 22 9 53 325 41 7.5 40 20.5 N 15.0 S 21.1 15 9 - 0 58.1 W 1453 34 19 58.5 18 59.5 S 19.0 N 17.0 7 Draconis S 22 21 38 37 40 35 39 46 W18.6 E 17.5 n N 27 10 322 10 44.5 9 44.5 W19.3 E 17.0 22 53 - 0 54.0 *) Comp. Dec. 4. 3) Cirrostratus, star invisible to the naked eye, but /3 Ursae Maj. found in the field 4°-5° lower. a) Circle ass. 38°. *) Circle ass. 321°. 6) Watch ass. Oh. 6) Cloudy, observation very difficult. 7) Circle-correction + 10' ass. by the observer. 8) Corr. to circle ass. — 10'. 12 GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 1895 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. - il 111 S 0 ' " / II h m m s Jan. 2 Capella N 22 4 13 43 56 3.5 55 15 E 18.0 W14.5 S 9 17 316 13 28 12 32 E 16.0 W16.4 rsse Maj. E 22 14 46 325 50 42 49 54.5 N 16.0 S 16.4 M W 20 11 34 8 30 7 52.5 N 16.0 S 16.3 22 52 +22 18.3 i) Jan. 5 y Draconis N 21 26 18 323 6 36.5 5 56 W16.2 E 14.9 21 12 - 1 8.0 n S 33 58 37 5 14.5 4 23 W16.0 E 14.9 « Ursee Maj. W 21 40 21 34 6 50 557.5 N 15.7 S 15.5 E 47 14 325 54 6 53 15 N 15.0 S 16.1 22 2 - 1 7.0 Jan. 8 rsee Maj. E 21 14 13 326 1 34.5 0 29 S 14.6 N 15.6 21 3 - 028.5 n W 19 37 33 60 11 59 5.7 N 15.6 S 16.0 •/ Draconis S 21 25 34 37 12 51.5 11 41.5 E 15.1 W17.5 N 32 4 322 37 56.5 36 31.5 W18.8 E 14.8 21 59 - 0 17.0 2) Jun. 11 rsso Maj. E 21 31 44.5 326 2 9.5 1 6.5 N 17.5 S 14.8 21 7 + 0 4.0 jj W 35 42 33 59 0.5 57 53.5 N 16.9 S 16.0 7 Draconis S 21 42 12.5 37 58 39.5 5735 W12.4 E 20.6 n N 46 39.0 321 54 27.5 53 15 W19.6 E 13.6 22 17 + 0 4.7 Jan. 13 a Ursee Maj. E 21 30 43 325 48 44 47 32.5 N 16.9 S 17.0 21 0 + 028.5 • W 37 26.5 34 11 26.5 10 19 N 17.0 S 17.5 ft Pegasi W 21 45 7.5 320 1 26 0 17 S 20.0 N 15.1 8) ji E 49 23.5 56 1 22 0 22.5 S 18.0 N 17.0 7 Draconis N 22 0 29 321 12 54 11 39 W15.4 E 19.8 ij S 4 30 38 55 40 54 26.5 W17.5 E 17.5 22 47 + 030.4 Jan. 14 Moon L. L. S 1 19 28 275 11 58 10 55 E 20.0 W15.2 Jupiter U.L W 1 25 37 298 17 11.5 16 5.5 S 20.4 N 15.0 Jupiter U. L W 1 56 8 298 49 40 4842.5 S 16.5 N 18.0 Moon L. L S 220 276 4 37.5 3 30.5 E 16.9 W17.9 2 31 + 0 32.5 Jan. 16 a Ursse Maj E 21 29 25 325 46 40 45 20.5 S 19.2 N 17.4 15 7 + 0 59.0 n W 33 59 34 13 54 12 35.5 S 18.6 N 17.9 7 Draconis S 21 46 47.5 38 44 45.5 43 33 W22.2 E 14.4 • N 52 18.4 321 7 15 5 54.5 E 15.0 W21.6 22 45 + 1 3.5 Jan. 18 a Urste Maj E 20 47 6.5 325 46 4 45 2 N 19.5 S 15.8 2029 + 0 22.7 4) f* W 51 7 34 15 6.5 13 57.5 N 17.7 S 17.6 / Draconis S 20 58 23 37 28 1.5 2655.5 W20.5 E 14.6 N 21 5 4.5 322 21 3 22 9 W17.7 E 17.8 21 28 + 1 22.5 Jan. 20 Polaris E 23 23 3 354 37 59 3655.5 N 16.0 S 18.0 23 0 + 1 47.9 71 W 26 32.5 5 23 38 22 36.5 N 18.0 S 16.6 o Cygni S 23 32 22 43 56 13 55 11 W20.5 E 14.0 N 37 2 315 57 8 55 45 W17.5 E 17.0 23 59 + 1 48.5 Jan. 22 Polaris E 22 54 9 354 39 6.5 38 17.5 N 16.7 S 19.0 2233 + 2 7.5 « W 59 0 5 22 25 21 27 N 19.9 S 16.0 a Cygni S 23 6 51 43 27 0 25 46 W18.3 E 17.7 n N 11 39 316 25 53 2435.5 E 17.6 W18.5 23 49 + 2 8.4 Jan. 25 Polaris E 22 13 15.5 354 39 29.5 38 35 N 18.0 S 17.5 21 52 + 2 39.5 H W 17 52 521 37 20 39 N 18.0 S 17.6 a Cygni S 22 25 10 42 38 16.5 37 14 W18.0 E 17.7 N 30 28.5 317 14 18.5 13 6.5 E 18.0 W17.7 22 49 + 240.3 Jan. 27 Polaris E 23 1 44 354 44 48 43 43.5 N 16.7 S 16.0 22 48 + 3 8.5 n W 5 31 5 16 34 15 28 N 17.0 S 15.5 a Cephei S 23 11 35 26 15 17.5 14 10 W15.9 E 16.8 ' N 15 51.5 333 38 41 37 35 E 16.5 W16.2 2333 + 3 9.4 Jan. 30 Polaris E 22 27 29.5 354 56 29.5 5529.5 N 16.1 S 15.0 22 11 + 350.0 fl W 32 12 5 5 11 4 5 N 23.1 S 8.0 a Cygni S 22 38 45 43 46 6.5 45 2 W14.7 E 16.8 N 4331 316 7 12 556 E 16.0 W15.3 23 18 + 3 51.0 Feb. 1 Polaris E 22 35 31.5 354 58 28 57 33 N 18.4 S 16.0 22 23 + 4 15.4 n W 40 8 5 3 12 2 3.5 N 18.2 S 16.1 !) Watch stopped shortly before. 2) Probably Hw-W. = - 0™ 27".0. star in this position of the instrument. *) Hw— W. ass. Im22s.7. 3) Probably another NO. 6.] ALTITUDES MEASURED WITH THE ALTAZIMUTHS. 13 1895 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. h m s Q 1 H / U h m m s Feb. 1 « Cygni s 22 46 23.5 44 10 3 9 5.5 W16.9 E 17.7 f) N 5040 315 44 29 43 9.5 E 16.2 W18.1 23 5 + 4 15.9 Feb. 4 Polaris E 22 9 9 354 48 57.5 48 2.5 N 13.0 S 20.4 15 3 + 4 52.0 ft W 14 11.5 5 12 49.5 11 50 N 18.2 S 15.1 a Cygni S 22 24 26.5 43 54 17.5 53 15.5 W16.2 E 17.3 n N 30 56 315 56 10.5 54 53 W16.5 E 17.1 22 50 + 456 Feb. B Regulus S 21 32 39 277 51 17 50 16.5 E 17.3 W17.0 21 9 + 5 11.0 Mars U. L. W 21 38 0 294 1 12 0 13 S 17.4 N 17.0 Moon U. L. s 21 42 47 299 36 18 35 5.5 E 17.2 W17.1 Mars U. L. W 22 2 7 294 20 21 19 12 N 18.0 S 16.9 Moon U. L. s 22 6 15 300 13 16 12 1 W18.0 E 17.0 Moon U. L. s 22 41 54 301 6 9 5 1 W18.9 E 16.0 Mars U. L. W 22 49 36 294 45 15 44 9 S 18.9 N 16.0 23 6 + 5 13.5 Feb. 6 « Cephei N 23 18 40 332 23 2.5 21 45 W17.0 E 18.5 22 48 + 5 27.0 S 23 25 27 45 35 44 18.5 E 18.0 W17.5 rsse Min. W 23 28 32 21 53 48 52 28.5 N 18.0 S 17.5 n E 32 29.5 £38 7 58.5 6 36.5 S 21.2 N 14.2 23 59 + 528.0 Feb. 8 Jupiter U. L. S 16 53 23.5 288 25 26 24 13.5 E 17.0 W180 15 57 + 5 52.0 ft N 57 24 71 31 36.5 30 24 E 19.8 W16.2 Moon U. L. W 17 3 4 76 47 5 45 46 N 16.5 S 19.5 n E 8 6 283 12 1.5 1053.5 S 18.0 N 18.0 Moon U. L. E 17 31 4.5 283 4 59.5 3 46 N 16.7 S 19.4 n W 34 52 76 57 0 55 47.5 N 18.7 S 17.5 Jupiter U. L. N 17 39 35 70 11 22 10 13.5 E 15.4 W20.7 ') W S 44 50 289 25 10 24 0 W17.0 E 19.3 a Ursse Maj. E 17 48 14 326 21 54.5 2036 N 16.3 S 19.8 71 W 52 41 33 42 37 41 14.5 S 16.5 N 19.5 18 52 + 5 54.0 Feb. 12 a Persei W 0 20 15 325 54 6 52 43.5 S 17.0 N 15.0 0 6 + 6 37.2 jl E 25 48 34 10 5.5 8 57 S 17.4 N 14.5 a Cephei S 0 39 21 30 28 19.5 26 57.5 W16.2 E 15.5 fl N 43 18 329 26 44.5 25 35 E 15.0 W16.9 0 57 + 6 37.5 Feb. 13 Polaris E 21 21 2 a>4 41 59 40 48.5 N 15.0 S 20.5 21 8 + 6 59.5 jj W 23 50 . 5 20 14.5 19 11 N 19.3 S 16.2 « Cygni S 21 2826 43 21 58.5 2049 W18.0 E 17.9 n N 31 56.5 316 33 42.5 32 24.5 E 18.0 W17.9 22 14 + 7 0.5 Feb. 17 a. Cephei N 22 20 23 332 41 42 40 30.5 W18.6 E 17.3 21 50 + 7 51.7 H S 26 7.5 27 29 17 28 7 W18.0 E 18.3 /£ Ursae Min. W 22 32 10 21 53 24 52 0 N 19.8 S 16.5 n E 37 14 338 8 1.5 6 43 N 20.0 S 16.1 22 55 + 7 53.5 Feb. 20 « Cephei N 22 15 53 332 28 53.5 27 44.5 W16.6 E 19.7 21 50 + 828.5 n S 2040 27 40 47.5 39 41.5 W21.2 E 15.0 /? Ursae Min. W 22 2557 21 45 54.5 4440 N 19.0 S 17.5 E 32 52 338 15 40.5 14 21.5 S 18.0 N 18.4 23 28 + 8 30.5 Feb. 23 /? Ursse Min. E 22 13 19 338 23 7 21 49 S 20.0 N 15.1 21 48 + 9 7.5 n W 19 6.0 21 39 2 37 53.5 N 19.7 S 15.5 a Cephei S 22 27 38 28 5 51 439.5 W17.0 E 18.4 H N 32 18 331 47 46 4633 W17.0 E 18.4 a Gemin. S 2241 58 304 46 3 44 54.5 W15.5 E 19.7 2) Ti N 45 19.5 55 8 24 7 25 E 19.4 W15.6 n Persei E 22 5038 34 17 9.5 1556.5 S 17.2 N 17.9 W 55 50 325 43 44 42 29 N 18.2 S 16.9 23 27 + 9 10 Feb. 24 rs« Min E 22 7 43.5 338 23 13.5 21 55.5 N 19.0 S 16.5 21 57 + 9 20.5 n W 12 25 21 38 14.5 37 6 N 19.0 S 16.9 a Cephei S 22 16 9 27 53 46.5 52 31.5 E 19.2 W16.7 n N 21 16 331 59 13 58 1 E 17.2 W18.7 22 33 + 9 21 Feb. 26 /£ Ursee Min E 22 5 9 338 28 41.5 27 26 S 17.0 N 17.5 21 48 + 946.4 n W 11 53 21 32 44.5 31 30.5 S 16.5 N 18.2 ') Circle-correction + 30' ass. by the observer. 2) Watch ass. 40«n. 14 GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 1895 Star Oc. Watch Vertical Circle Level Watch Hw-W. Rem. h m s 0 ' " 1 II h m m s Feb. 26 o Cephei S 22 18 14 28 8 12.5 7 3 W16.0 E 18.7 n N 24 5 331 44 10 42 56.5 E 21.0 W13.5 15 1 + 9 55.2 ») Mar. 2 ;» Draconis E 1 3 39 315 35 17 34 5 N 10.4 S 18.2 0 48 - 2 27.8 W 8 13.5 44 26 9.5 25 1.5 N 18.5 S 16.5 rsse Maj. N 1 14 33.5 26 41 37.5 40 32 E 16.4 W18.6 2) S 20 0 333 27 53.5 26 35.5 W18.8 E 16.4 1 46 - 2 27.7 Mar. 4 / Draconis E 1 2 14.5 315 36 15.5 3452.5 N 15.0 S 19.9 0 49 - 2 7.0 W 631 44 25 18.5 24 9 N 18.0 S 16.9 a Ursse Maj. N 1 10 32.5 26 36 41 35 30 E 19.0 W15.9 71 S 15 26 333 32 8.5 30 57.5 W16.0 E 19.0 1 29 - 2 6.5 2) Mar. 6 / Draconis E 1 22 54 315 36 49 35 28.5 N 15.7 S 18.1 0 51 - 1 41.5 W 26 22 44 23 52 22 39 N 16.4 S 17.5 a Ursa) Maj. N 1 30 4 25 5053.5 49 55.5 E 19.0 W15.0 S 33 53 334 16 12.5 15 1 W16.0 E 17.8 1 48 - 1 41.0 Mar. 9 y Draconis E 058 23 315 31 21 30 15.5 N 12.3 S 21.0 046 - 1 4.2 W 1 2 10 44 29 56.5 28 59.5 N 17.0 S 16.6 a Ursse Maj. N 1 5 57 26 5 37.5 4 27 E 19.9 W13.9 n S 9 8.5 333 60 42 5939 W16.0 E 17.8 Jupiter U. L. W 1 22 14 299 17 28.5 16 13 S 14.3 N 19.5 Moon U. L. S 1 26 8.5 288 21 12 20 11 E 18.6 W15.2 Moon U. L. S 1 43 53 288 37 8 36 4 E 19.0 W15.0 Jupiter U.L. W 1 47 35 299 5 40.5 4 30.5 S 16.4 N 17.0 2 8 - 1 3.7 Mar. 10 Sun U. L. N 21 2 43 271 17 4 16 13 W14.5 E 19.8 2039 - 0 38.5 n S 9 6 8849 59 49 7.5 W16.8 E 17.6 3) n S 20 47 88 60 18.5 59 34 W16.0 E 18.4 n N 25 44 270 55 21 5428.5 W16.6 E 17.2 rs N 34 45 270 46 58.5 46 9.5 E 19.0 W15.3 n S 4058 89 18 37.5 17 46.5 W18.2 E 16.1 rt S 46 0 89 23 20.5 22 18.5 W18.0 E 16.5 4) n N 22 0 0 270 24 47.5 23 45.5 W18.0 E 16.7 «) False Hor. E. N 8940 39.5 E 17.0 W17.5 Horizon East N _ 8947.5 46.5 E 16.2 W18.2 22 44 - 0 37.0 Mar. 11 / Draconis E 0 47 36 315 31 38 30 24.5 S 19.5 N 15.1 0 36 - 036.0 « W 52 9 44 2844 29 34 N 18.0 S 16.6 a Ursoe Maj. N 0 59 41 26 1 57 049.5 W18.8 E 16.0 S 1 3 35 334 5 24.5 4 12 W17.1 E 17.7 1 29 - 0 35.8 Mar. 13 / Draconis E 0 46 49.5 31537 5.5 35 41 N 17.5 S 15.2 W 50 14 44 24 3.5 22 56 N 18.4 S 14.4 n Ursa; Maj. N 0 56 15.5 26 1 32 0 22.5 E 18.2 W14.8 S 59 59.5 334 5 13 4 6.5 E 16.7 W16.3 1 14 - 2 15.0 Mar. 16 / Draconis E 0 51 44 315 43 20 41 59.5 N 16.6 S 16.3 15 10 - 1 45.3 6) M W 56 18 44 17 3 16 0 N 17.0 S 16.4