bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of Maunder's recent investigations on the cause of magnetic disturbances
Authors: Chree Charles
Published: February 2008

The material consists of 276 magnetic storms, the largest recorded at Greenwich during 22 years. In selecting and describing them Mr. Maunder employs criteria originally proposed by Mr. W. Ellis. These are arbitrary, and appropriate only to stations similarly disturbed to Greenwich, but they give a general idea of the size of the disturbance. Mr. Maunder's Table I arranges the storms chronologically, assigning definite hours for their beginning and end, and gives the amplitude of the largest movement in declination and in horizontal and vertical force.
Nachtrag zur Abhandlung: “Über den Einfluss der Torsion bei den Ablenkungen eines hängenden Magneten”
Authors: Bidlingmaier F.
Published: February 2008

Der Güte der Herren Adolf Schmidt‐Potsdam und C. Börgen‐Wilhemshaven verdanke ich die Mitteilung, dass die obige Frage bereits von Herrn Solander in den “Mitteilungen der Königl. Gesellschaft zu Upsala 1889” behandelt und seine Arbeit von Herrn Liznar in der “Meteorologischen Zeitschrift” 1889 (Litteraturbericht [page 74]) besprochen ist. Dies war mir entgangen. Meine Arbeit ist im völligen Einklang mit der obigen, giebt jedoch eine Art der Correction mehr, die Correction aus den Messungen in zwei Entfernungen.
Tortosa Observatorio del Ebro
Authors: Cirera R.
Published: February 2008

Preliminary inforlnation regarding this Observatory has already been given in Note 20, Vol. VIII, p. 189. The following additional information has been courteously supplied by Father Cirera, under the date of October 19, 1904. Father Cirera has promised his cordial co‐operation in the proposed magnetic and electric observations during the total solar eclipse of August 29, 30, 1905. He says:

“We are completing the installation of our magnetic pavilions which will soon be ready for work. They are two in number. The first contains in a subterranean structure of two rooms two complete sets of Mascart's instruments for the measurement of the variations of the Earth's magnetism. One of these sets will be provided with a photographic registration apparatus, and the other with telescopes for direct observations. For self‐registration the acetylene light will be used, and the trace is made on a cylinder unwinding in an hour two centimetres of sensitized paper. The second pavilion is to be used for absolute measurements. For the observations of magnetic declination and of the horizontal intensity a unifilar magnetometer of the Kew pattern will be used, and for the measurement of the inclination, an earth‐inductor of the Potsdam pattern will be employed. The photographic view represents the general view of our Observatory; the two buildings in the upper right‐hand corner marked 6 and 7, represent, respectively, the variation and the absolute magnetic pavilions.”
Work of the department of terrestrial magnetism of the Carnegie Institution for 1905
Authors: Bauer L. A.
Published: February 2008

I. Continuation of the study of the secular variation and compilation of data and preparation for publication on a comprehensive, uniform plan. [The investigations have already progressed far enough to have warranted beginning at once the observational work referred to below.]

II. Discussion and publication of the data on the magnetic perturbation observed during the eruption of Mont Pelée, Martinique, 1902. [It is hoped to have this work in published form by end of year.]
Results of harmonic analysis of the diurnal variation at the Cape of Good Hope and at Hobart
Authors: Heimbrod G.
Published: February 2008

The present paper is a continuation of my former one1 and deals with the harmonic analysis of the horizontal and vertical intensities. The data upon which the analysis is based are those tables in Sabine's publication, which give the position of the bifilar and of the vertical force magnet with reference to the mean position during the month, a plus (+) sign indicating that the force is greater than the mean and vice versa. In the original publications, the diurnal variation quantities are expressed in British units and in parts of H and Z. The computation has been carried out from the original figures and the values of pn and qn were then converted into C.G.S. units.
Irkutsk Magnetic Observatory
Authors: Rykatscheff H.
Published: February 2008

In continuation of the information respecting the present Russian magnetic observatories already furnished (c.f. this volume, p. 55), it can now be stated that the Irkutsk Magnetic Observatory has likewise continuous magnetic registrations since December, 1904.
Magnetic observations made in Egypt during the total eclipse of August 29/30, 1905
Authors: Wade E. B. H.
Published: February 2008

The attention of the Director General of the Egyptian Survey Department (Capt. H. G. Lyons) having been drawn by Dr. Bauer to an international scheme of synchronous magnetic observations to be made on the occasion of the total eclipse of the Sun of August, 1905, it was arranged by him that three parties should be equipped with absolute instruments of the Kew pattern for the purpose of co‐operation. As there were only two such instruments belonging to the Department, a third was ordered specially from Messrs. Elliott's.

The final choice of observers and stations was as follows: Near the southern limit of totality, Mr. MacPherson, at Gertasse, latitude 23° 41′ N, longitude 32° 54′ E of Greenwich; near the central line, the writer, assisted by Mr. Forte, at Aswan, latitude 24° 05′, longitude 32° 56′ E; and near the northern limit, Mr. Freeman at the temple of Edfu, latitude 24° 59′ N, longitude 32° 53′ E.
Principal magnetic disturbances recorded at Cheltenham Magnetic Observatory, January 1 to April 30, 1906
Authors: Wallis W. F.
Published: February 2008

I. Moderate disturbance. Began about 17h. on February 5th and ended about 12h. on February 11th.
Sopra le perturbazioni magnetiche dovute al terremoto della calabria dell' 8 Settembre 1905
Authors: Rizzo G. B.
Published: February 2008

Lo studio dei fenomeni magnetici che accompagnano spesso i movimenti del suolo offre il più grande interesse e moltissimi investigatori se ne sono occupati (1). Le numerose osservazioni raccolte intorno a questo argomento dimostrano che talvolta, in occasione di forti terremoti, anche le calamite degli apparecchi magnetici fanno delle oscillazioni più o meno ampie intorno alle loro posizioni d'equilibrio; anzi, stando a qualche osservazione isolata, corne quella, ehe si ricorda spesso, del P. Eschinardi (2), si produrrebbero anche delle variazioni permanenti negli elementi del magnetismo terrestre. Ma, senza negare in modo assoluto che cio' sia possibile, sembra più raginevole ammettere che queste supposte variazioni permanenti siano dovute a qualche cambiamento accidentale avvenuto nella disposizione dello strumento durante la scossa.
Measurements of the electric potential during the total solar eclipse of August 30, 1905, at Tripoli, Barbary
Authors: Oddone Emilio
Published: February 2008

The writer participated in the expedition which the Department of Terrestrial Magnetism of the Carnegie Institution of Washington had entrusted in 1905 to Professor Palazzo, with the object of studying within or near the region of totality the variations of the elements of atmospheric electricity and of terrestrial magnetism. Professor Palazzo delegated to him the part relating to the electric and actinometric measurements; this report is confined to an account of the electric observations.

The plan prepared for the making of the electric measurements was very simple, and consisted in obtaining the continuous course of the potential on the day of the eclipse and during several days before and after the eclipse. The station chosen was Tripoli, Barbary, the apparatus having been set up on the upper floor of the Italian Royal Technical Commercial School. As was natural the electric conductors were placed on the terrace above, whereas the rooms immediately below the same were chosen for the placing of the electrometers.
Contribution to the study of the effects produced on the magnetic declination by the total solar eclipse of August 30, 1905
Authors: Nordmann Charles
Published: February 2008

Besides experiments relative to atmospheric electricity of which brief accounts have already been given elsewhere,2 I obtained at Philippeville, Algiers, between August 14 and September 20, 1905, continuous registrations of variations of the magnetic declination and of. the horizontal intensity with the purpose of discovering a possible influence of the eclipse on the usual course of the diurnal variation of these elements. The instruments were installed under excellent conditions inside a casemate where the temperature and the hygrometric conditions were extremely constant, (the daily variation of the temperature there being less than 0.°1C.) The description of the apparatus,3 as well as the details of the results relative to the absolute values of the magnetic elements at the place of observation and to their normal diurnal variation, will be presented in a memoir of the “Annales du Bureau des Longitudes” now in preparation. I will confine myself at present to giving some brief observations as to the results obtained on the day of the eclipse.
What is the Earth's magnetic axis and its secular motion?
Authors: Bauer L. A.
Published: February 2008

According to van Bemmelen's investigation, contained in this number of the Journal, it would appear that since about 1840 the northern end of his “mean magnetic axis” of the Earth, deduced from magnetic declinations alone, has been moving in a northwest direction, i.e., increasing its north latitude and west longitude. Prior to 1840, as will appear from his figure, the secular motion, since the year 1600, had been southward, north latitude being decreased throughout; during part of this period (1600–1700 about) west longitude was decreased and during the remainder of the period it was increased.

In the second paragraph of his article, van Bemmelen cites the determinations of the magnetic axis by Erman and Peterson for the epoch 1829, and of Schmidt for 1885, their values being derived from a harmonic analysis of all the magnetic elements, not from declinations alone, as in van Bemmelen's case. The comparison there given would likewise, apparently, indicate that the motion was northwestward for this period, although the increase in latitude was not as pronounced as van Bemmelen had found.
Luftelektrische Messungen auf See
Authors: Lüdeling G.
Published: February 2008

Auf meine Anregung wird der Stabsarzt in der Kaiserl. Deutschen Marine, Dr. Ploeger, auf einer 2jährigen Auslandsreise luftelektrische Messungen auf See anstellen. Die Beobachtungen haben bereits auf dem Transportdampfer “Borussia” während der Fahrt von Wilhelmshaven nach Tsingtau begonnen und werden später an Bord S. M. S. “Iltis” in den Ostasiatischen Gewässern fortgesetzt werden. Es handelt sich dabei hauptsächlich um regelmassige Messungen der luftelektrischen Zerstreuung mit einem Apparat von Elster u. Geitel, der Radioaktivität der freien Luft, der radioaktiven Emanation des Seewassers, sowie endlich des Staubgehalts der Luft mit Aitken'schen Staubzähler.
Proposed atmospheric electricity work on the magnetic survey yacht “Galilee” in 1907
Authors: Dike P. H.
Published: February 2008

In accordance with instructions from the Director of the Department Terrestrial Magnetism of the Carnegie Institution of Washington, the undersigned will join the magnetic survey yacht Galilee at Sitka about Aug. 1st and attempt, in connection with the ship's regular magnetic work, the following atmospheric electricity observations during a cruise in the Pacific Ocean. The main purpose at present is to acquire the necessary experience. Hence the work must necessarily be largely experimental.
The magnetic storms of September 1908
Authors: Tittmann O. H.
Published: February 2008

During the month of September, 1908, there were two magnetic storms of unusual severity, one beginning on the 11th and the other on the 28th. There was also a storm on the 4th and 5th greater than any that had been recorded at the Cheltenham Magnetic Observatory since March1, but it did not approach the magnitude of those occurring later in the month. Some details of these two storms, as recorded by the Eschenhagen magnetograph at Cheltenham, may be of interest. The normal values for that place are approximately as follows: Declination (D) 5° 31′ West; horizontal intensity (H) 19,930 gammas; vertical intensity (Z) 56,350 gammas.
The magnetic character of the year 1907
Authors: van Everdingen E.
Published: February 2008

The second annual review of the “Caractère magnétique de chaque jour” (see Terrestrial Magnetism, vol. X, p. 197; vol. XII, p. 183; vol. XIII, p, 36) states that 37 observatories contributed to the quarterly reviews, and that 32 sent complete data for 1907. Two among the observatories partaking for the first time described their method of classification.

The annual review has been drawn up in the same manner as for the first year (1906): the second Table and the list of “calm days” are reprinted here.
A graphical aid to latitude and azimuth computation from polaris observations
Authors: Fisk H. W.
Published: February 2008

The following device has been designed to facilitate the computation of latitude and azimuth from observations on Polaris. It is assumed that the computer has access to the tables of the declination and right ascension of the star, also of the right ascension of the mean Sun, from which he can find the star's hour angle in the usual way.

There are conditions where it seems best to compute the values of latitudes and azimuth directly from observations, rather than to make use of tables computed for various latitudes, months, years and hour angles. It is for such conditions, and where the accuracy demanded is of the order of 0.′1, that this method has been designed.
The present state of our knowledge of magnetic materials
Authors: Knowlton A. A.
Published: February 2008

The amount of experimental work upon the subject of magnetic materials, within the past few years, is indicated by the fact that the indices of Science Abstracts since 1900 contain references to more than five hundred papers on this subject. This number does not include those papers dealing with the electro‐magnetic field, nor papers of a strictly technical nature. The writer originally undertook to collect from this material the most important results with a view to clarifying his own knowledge of the subject, and his only excuse for the presentation of this paper lies in the hope that such a summary of recent work as is here undertaken may do a like service for others.

One of the most important results of the recent studies has been the increasing recognition of the distinction between para‐magnetism and the magnetism of those substances which resemble iron and which have come to be called ferro‐magnetic. This distinction is well illustrated by the differences between the magnetic behavior of iron and of iron salts in solution. The latter are distinctly paramagnetic, i.e., a tube containing such a solution sets itself along the lines of force of a magnetic field, and is acted upon by a force drawing it into the strongest part of the field. But according to the result of Heydweiller (Ann. der Physik, 1903) the susceptibility of such solutions is a constant for field strengths between 0.1 and 40000 C. G. S. units. In other words, the phenomenon of saturation, so characteristic of iron and all other substances commonly spoken of as magnetic, is here lacking. This points to a very fundamental difference between the nature of para‐magnetic and ferro‐magnetic substances—a difference which is probably not greater than that existing between para‐magnetism and dia‐magnetism.
Beginning and propagation of the magnetic disturbance of May 8, 1902, and of some other magnetic storms
Authors: Bauer L. A.
Published: February 2008

On May 8, 1902, as may be recalled, there occurred shortly before eight in the morning one of the most interesting eruptions on record—that of Mont Pelé. According to the late Professor Angelo Heilprin, the clock on the military hospital of St. Pierre was found stopped at 7h 52m A.M., St. Pierre local mean time. Some reports give the time of beginning of the outbreak as 7h 50m A.M.

This eruption was not accompanied by any great outpour of ashes or flow of lava, there were no earthquake effects nor such barometric fluctuations as were observed in connection with the great eruption of Krakatoa in 1883. Instead there was violently ejected a cloud consisting of fine dust and a gaseous vapor whose death‐dealing, scorching blast overwhelmed the stricken inhabitants of St. Pierre and caused complete extinction of life in but a few minutes. All reports dwell particularly on the pronounced electrical phenomena beheld above Mont Pelé.
Analysis of the magnetic disturbance of January 26, 1903, and general considerations regarding magnetic changes
Authors: Bauer L. A.
Published: February 2008

Among the very notable advances made with regard to the origin and formation of magnetic storms, must be counted the experimental and observational results of Birkeland and the mathematical work of his colleague, Störmer. Birkeland's recently published volume1 presents a wealth of material to the student of terrestrial magnetism.

At present, however, Birkeland's results and deductions must be regarded chiefly as qualitative. While he makes very plausible that the cause of our magnetic storms is chiefly to be referred to cathode rays originating in the Sun and coming within reach of the Earth's magnetic field, there are a great many questions left open which will require answering before full acceptance can be given to the theory. And no one appears to be better aware of this fact than Birkeland himself. I am sure, therefore, that he will welcome any additional light that may be shed.
Aurora Borealis observed at Beinn Bhreagh, Near Baddeck, Nova Scotia, September 21 and October 18, 1909
Authors: Bell Alexander Graham
Published: February 2008

September 21, 1909. Fine display of Aurora Borealis visible here this evening at 7 minutes past 8, covering the northern half of the sky and extending up to the zenith. Whole northern sky covered from East to West; southern half clear. The western edge of the luminous curtain passes through the bright star Alpha Lyrae. Gentle streamers go up from all points of the northern half of the horizon to a point in the northern cross, which seems to be overhead.
Westman's observations on the Aurora Borealis
Authors: Edmonds H. M. W.
Published: February 2008

This volume on the Aurora Borealis forms part of the scientific work done in connection with the measurement of a meridian arc on Spitzbergen Island by the Swedish and Russian Governments in 1899 to 1902. The locality of observations was at the Bay of Treurenberg in latitude 79°55′.1 N., and longitude 16°51′.5 east of Greenwich. The observations were to follow the methods of those of the Swedish expedition of 1882–3. Daily observations were obligatory at certain stated hours, and on every fifth day every quarter hour between 8 and 10 P.M. Greenwich mean time.
On precursors of magnetic storms
Authors: Faris R. L.
Published: February 2008

In the issue of “Nature” of April 28» 1910 (p. 254), the Rev. J. de Moidrey, director of the magnetic observatory at Zi‐ka‐wei, China, gives some notes on what he has termed the “precursor” of magnetic storms observed by him on the records of his observatory as preceding the magnetic storms which have sudden beginnings. As he asks for further information on the subject from other observatories these notes are submitted.

In defining what he terms “precursors,” de Moidrey states “that disturbances with a ‘sudden start’ very generally have a kind of ‘preliminary tremor’ some hours before the start; the curve, which we suppose to be quite smooth, is interrupted by a short movement, which lasts but for the remaining hours. The tremor may be very small indeed, but the two characteristics, to be found on a smooth curve, and to be of very short duration, make it very easy to point out and tell the time.”
Die magnetische Deklination in Tsingtau und ihre Jährliche Änderung
Authors: Meyermann Von B.
Published: February 2008

Im Laufe dieses Jahres wird das neue Observatorium in Tsingtau so weit fertiggestellt sein, dass mit der regelmässigen Beobachtung und Registrierung der 3 magnetischen Elemente begonnen werden kann. Seit mehreren Jahren wird die Deklination hier bereits beobachtet. Registrierungen finden jedoch erst seit April 1910 statt und diese sind nicht als vollwertig anzusehen, da die Variationsinstrumente vorläufig in einem alten Chinesenhause untergebracht sind, das noch zum Teil bewohnt ist. Zum Ableiten von Monats‐ und Tagesmitteln eignen sich die Kurven daher kaum.
The magnetic character of the year 1911
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1911 has been drawn up in the same manner as for the preceding years. Forty‐five observatories contributed to the quarterly reviews; when the tables were dressed, 39 of them had sent complete data. Several observatories have somewhat modified their method of classification on account of a circular sent in March. Table II of the annual review, containing the mean character of each day and of each month and the list of “calm days,” are reprinted here.
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, October 1 to December 31, 1912
Authors: Hartnell George , Tittmann O. H.
Published: February 2008

Not alone in the duties and observations of the positions occupied by Messerschmitt did his ability and energy show themselves. He belonged to many societies and organizations, in all of which he took a very active and prominent part, as treasurer, secretary, or as an active committee member. He is author of numerous publications, both scien‐ tific and popular. Whatever he undertook received his devoted care and unceasing enthusism.1
Regarding magnetic observations, April 17, 1912
Authors: Kalinowski St.
Published: February 2008

I am much obliged to Mr. de Moidrey for his kindness in publishing the magnetic curves obtained during the eclipse of the Sun on April 17, 1912, at Lu‐kia‐pang.1 When I stated in my note2 that it would be very desirable to have some data from stations situated to the east of Warsaw, I had in mind some point much nearer than Lu‐kia‐pang, for example at a distance about equal to that between Beuthen and Potsdam from Warsaw. It is only in such a case that one could account for the difference between the data of Warsaw, Beuthen and Potsdam. The curves of De Bilt published by Mr. G. van Dijk3 seem to confirm my supposition.
Magnetic observations at the Tucson Magnetic Observatory for 1909 and 1910
Authors: Wallis W. F.
Published: February 2008

The buildings for this observatory were completed in October, 1909. The magnetographs previously in operation at Baldwin, Kansas, were removed to Tucson and installed at the new observatory.

The variation building is a wooden structure, entirely above ground. Temperature insulation is secured by means of air spaces and sawdust packing. Immediately surrounding the instrument room is a 15‐inch space filled with sawdust; then a 26‐inch air space (corridor); next a 6‐inch dead‐air space; then a 40‐inch space filled with sawdust; and finally a 6‐inch free‐air space between the studding. Within the instrument room the daily range of temperature is about 0.°1C., and the annual range about 15°. The instruments are D, H and Z variometers of the Eschenhagen pattern.
On a new method for determining the Earth's horizontal magnetic forces
Authors: Schuster Arthur
Published: February 2008

Since Gauss first introduced the present method of measuring magnetic forces, magneticians have been trying to obtain the increased accuracy required in modern physical measurements by refining details and introducing a number of corrections. The limit of such a procedure—which in this case has perhaps already been overstepped—is reached when the amount of added labor ceases to lead to a corresponding gain. It becomes necessary then to consider whether the method itself should not be abandoned.

Electric currents can now be measured so accurately, and so much experience has been gained in winding standard coils, that it is worth enquiring whether magnetic forces cannot be conveniently measured by using artificially prepared magnetic fields as standards of comparison. To me it appears to be beyond doubt that greater accuracy can be obtained in this way with far less expenditure of labor, and, as far as fixed observatories are concerned, the time seems ripe to make the change.
On the non‐cyclic change
Authors: Steiner L.
Published: February 2008

In the following paragraphs is given a short account of the investigations, which I have made, concerning the non‐cyclic change. Although the investigations are of a somewhat fragmentary character, yet it seemed worth while to publish the results, as they contribute something, at least, to our knowledge of this non‐cyclic change.

1. The non‐cyclic change, as defined by Doctor Chree, is the difference of the two consecutive midnight‐values of the magnetic elements on a quiet day. Instead of taking the difference of the midnight‐values, I have taken the difference of the daily means on two consecutive quiet days. I have chosen the observations at the magnetic observatories of the United States Coast and Geodetic Survey, the uniformity in the selection of the quiet days for the different places being thus, I assumed, best secured. The geographical positions of these places are:Latitude Longitude(North) (West of Greenwich)° ′ ° ′Sitka........................................57 03 135 20Baldwin..................................38 47 95 10Cheltenham............................38 44 76 51Honolulu................................21 19 158 04Vieques, Puerto Rico..............18 09 65 26 (old location.)
The local magnetic constant and its variations
Authors: Bauer L. A.
Published: February 2008

Good progress has been made by various investigators in establishing the relationship between fluctuations of the Earth's magnetism and those of the Sun's activity during the Sun‐spot cycle. The magnetic quantity most frequently used for this purpose has been the range of the diurnal variation—generally of the magnetic declination. In connection with a preliminary examination of this relationship made five years ago in response to an inquiry received from Professor Hale, director of the Mount Wilson Solar Observatory, I had occasion to employ various other magnetic quantities. One of these was what is here termed the “local magnetic constant,” which, under certain assumptions, is proportional to the magnetic moment of the Earth, or to the intensity of magnetization.
The magnetic character of the year 1913
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1913 has been drawn up in the same manner as the preceding years. Forty‐three observatories contributed to the quarterly reviews; 42 of them sent complete data. Table II of the annual review, containing the mean character of each day and of each month, the list of “calm days” and the days recommended for reproduction are reprinted here.
The magnetic character of the year 1915
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1915 has been drawn up in the same manner as the preceding years. Thirty‐eight observatories contributed to the quarterly reviews; 35 of them sent complete data. Table II of the annual review, containing the mean character of each day and each month, the list of “calm days” and the days recommended for reproduction are reprinted here.
Summary of results of the Aurora‐Borealis expedition of 1913 to Bossekop, Norway
Authors: Störmer Carl
Published: February 2008

In this Journal I have published preliminary reports on the results of the Aurora‐Borealis Expedition undertaken by me in the spring of 1913 to Bossekop, in the northern part of Norway. I now propose to give a summary of the chief results.

Altitude and situation of auroras.
The height of the aurora borealis according to observations at the Haldde Observatory, Norway
Authors: Vegard L. , Krogness O.
Published: February 2008

The Haldde Observatory, which is situated in the north of Norway on the Haldde‐Top near the Alten Fjord 904 meters above sea level, was built by the Norwegian government during the years 1911–1913 on the initiative of Professor Kr. Birkeland. Its main object is to make observations and carry out research along the lines drawn in Birkeland's well‐known publications on the aurora borealis, magnetic disturbances, and allied cosmic and meteorologic phenomena. In a previous publication1 we have given the results of some height‐measurements of the aurora borealis, made by us in the winter of 1912–13. In these and in later observations we have been using the photographic method first adopted by Professor Störmer in 19102.
The measurement of variations in the Earth's magnetic field
Authors: Bell H.
Published: February 2008

There does not seem to be at present any systematic method in general use for measuring simultaneously very rapid changes in all three components of the Earth's magnetic field. The suspended magnetic needle gives only an integrated value of the couple acting upon it, for since its moment of inertia is always considerable, its period is always great in comparison with such rapid changes. There is, therefore, no evidence from this source for or against rapid changes. A method is described in Terrestrial Magnetism (vol. 12, pp. 1–14, 1907), by Ebert, whereby rapid changes in the vertical component Z can and have been measured; the first part (I) of the present paper is to show that by a slight extension of Ebert's method we can determine with accuracy the motion of the magnetic‐force vector during normal days, and, what is more important, determine the motion of the vector during a magnetic storm.
The influence of solar activity on the lunar‐diurnal magnetic variation
Authors: Chapman S.
Published: February 2008

In various recent papers1 I have discussed the lunar‐diurnal magnetic variation, advocating the theory that it is due to the combined influence of a lunar atmospheric tide and of a solar ionizing effect in the upper regions of the air. This theory, as I pointed out in a former note2 in this Journal, almost inevitably requires a close parallelism between the solar‐ and lunar‐diurnal variations, consequent upon changes in the solar activity. Many investigators3 have examined the lunar variations to test this point, but without arriving at any general agreement upon it.Sabine, treating observations from St. Helena, Toronto, the Cape and Hobarton, Chambers and Figee dealing, respectively, with data from Bombay and Batavia, all concluded that the lunar‐diurnal magnetic variation showed no regular dependence upon solar activity. On the other hand Broun, from the Trevandrum declination observations, and van der Stok, from a series of Batavia observations (shorter than that dealt with by Figee, however), concluded that the lunar‐diurnal variation was greater at Sunspot maximum than at Sunspot minimum.
On the influence of lunar declination on the lunar‐diurnal variation of magnetic declination at Zikawei
Authors: Chapman S.
Published: February 2008

Having read with much interest Father J. de Moidrey's investigation of the influence of lunar declination on the lunar‐diurnal variation of magnetic declination at Zikawei,1 and desiring to see how far theory could account for his results, I decided to calculate the Fourier coefficients of the first two harmonic components of the variations: (a) for the whole saros 1890–1908; (b) for the days when the Moon was at or near its nodes; and (c, d) for the epochs of maximum north and south declination, respectively. The results are given in Table 1.

As regards order of magnitude, the results for the saros may be compared with similar data obtained, from other periods of years and by other methods of computation, by Dr. van Bemmelen2 and the present writer.3 Dr. van Bemmelen dealt with the period 1890–1900, while my own data refer to the years 1897–1903. The three sets of figures are given in Table 2, which refers to the annual mean lunar‐diurnal variation of the various elements over terms of several years.
The influence of changes in lunar distance upon the lunar‐diurnal magnetic variation
Authors: Chapman S.
Published: February 2008

In a recent paper in the “Philosophical Transactions” (A. 215, p. 161, 1915) I discussed the influence of changes in the Moon's distance upon the amplitude and phase of the semidiurnal component of the lunar‐diurnal magnetic variation. It appeared that the amplitude (c2) increases from apogee to perigee by an amount comparable with, though perhaps rather less than, the increase in the tidal force of the Moon (i.e., nearly proportional to distance −3). During the same time the phase angle (θ2) advances through about 20° or 25°. The former result was regarded as supporting the hypothesis that the lunar‐diurnal magnetic variation is a consequence of a lunar tide in the atmosphere.
Magnetic observations made at Rivière du Loup, Canada, during the solar eclipse of June 8, 1918
Authors: French C. A.
Published: February 2008

I am sending herewith the results of the special magnetic declination observations taken on June 8 in behalf of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, as well as additional observations taken at the eclipse station. Only part of the observations taken at the eclipse station are included, for the reason that during a greater part of the week, June 10–15, magnetic conditions were very disturbed.... As June 13 was the least disturbed of any day during the week, I am sending the dip observations taken on that day. The observations of declination, also the afternoon observations of horizontal intensity of June 13 are also included.
Observations at the Lukiapang Magnetic Observatory during the solar eclipse of June 8, 1918
Authors: de Moidrey J.
Published: February 2008

I beg to transmit a copy of our magnetograms during the eclipse of June 8, 1918, Greenwich civil mean time.

The scale values are for one millimeter of ordinate: 0′.48 (Declination); 1.87γ (horizontal intensity) and 5.5 to 4.8γ (vertical intensity).
A comparative study of magnetic declination at Agincourt and Meanook during 1917
Authors: Jackson W. E. W.
Published: February 2008

In July of 1916 there was established at Meanook, Alberta, a magnetic observatory for the purpose of securing a continuous photographic record of the magnetic declination. The record for the first calendar year was completed on December 31, 1917 and a preliminary analysis of the results obtained is here presented together with a comparative analysis of the results obtained at Agincourt. The Meanook station is located in longitude 113° 21′W and latitude 54° 37′ N, and the Agincourt station in longitude 79° 16′ W and latitude 43° 47′ N.

At Meanook 105th. mean time is used and at Agincourt, 75th. mean time; the time‐clocks are compared daily with chronometers whose errors are allowed to accumulate and whose rates are determined weekly by telegraph. By the addition or subtraction of small weights to the pendulum of the time‐clocks they are kept within a few seconds of the true standard time, and they are provided with electrical contrivances to mark the hours on the photographic records.
Similarities between the Earth current observed at Jersey, England, and an electric tide derived from the ocean tide
Authors: Deschevrens Marc
Published: February 2008

In my second note on the natural electric current observed under ground at Jersey, England, I showed that its diurnal variation obeyed a law similar to that which governs the ocean tide and that it may be concluded that there exists in the soil an electric tide which is the counterpart of the ocean tide. Pursuing further this interesting investigation, I have found that these two tides should be considered as related to each other even to such an extent that the first may be regarded as derived from the second. My opinion is based on the following points:

1. The two tides present a common form of diurnal variation which is not a double regular sinusoid, since the intervals of the phases are not equal.
The vertical‐intensity variometer
Authors: Hartnell George
Published: February 2008

For the purpose of recording the variations of the three magnetic elements, declination (D), horizontal intensity (H), and vertical intensity (Z), magnetic observatories use three instruments collectively called a magnetograph. One instrument called the D‐variometer or sometimes the unifilar variometer records variations in declination; its magnet is suspended horizontally with north end of the magnet north in the magnetic meridian, by a single fibre of silk or quartz. Another, with north end of the magnet either east or west, is suspended in a horizontal plane by either a single fibre of quartz, or by a bifilar suspension of silk fibres; it records variation of the horizontal intensity and is called the H‐variometer. In the case of the bifilar suspension it is sometimes called the bifilar variometer.
Ueber die Bestimmung der Inklination mit dem Induktions‐Inklinator
Authors: Uljanin Von W.
Published: February 2008

Gegenwärtig wird an den meisten magnetischen Observatorien der Inklinationswinkel mittels des Wild'schen Induktions‐Inklinators bestimmt, der unbedingte Vorzüge vor dem Nadelinklinator besitzt. Dabei wird die Induktionsspule mittels biegsamer Welle in rasche Rotation versetzt und der durch einen Kollektor gleichgerichtete Induktionsstrom einem empfindlichen, starkgedämpften Galvanometer zugeführt. Die Rotationsaxe wird vorher nach einer Magnetnadel in die Meridianebene eingestellt und jetzt in derselben so geneigt, dass der Galvanometerstrom verschwindet. Dann fällt die Rotationsaxe in die magnetische Feldrichtung und der Inklinationswinkel wird direkt am Vertikalkreis abgelesen.
The cruise of the Carnegie for 1919–1921
Authors: Ault J. P.
Published: February 2008

The magnetic‐survey vessel, Carnegie, after having been out of commission since her arrival at Washington in June 1918, has been completely overhauled and put in good repair for another cruise of world‐wide extent. The tentative schedule is as follows:
The magnetic storm of August 11–12, 1911, as observed at the Cheltenham Magnetic Observatory
Authors: Hartnell Geo
Published: February 2008

A magnetic storm of extraordinary magnitude occurred on August 11, 1919, at the magnetic observatory of the United States Coast and Geodetic Survey, latitude 38° 44′ N. and longitude 76° 50′.5 W. It began abruptly at 1h 58m 75th meridian time, A.M., August 11. The first movement in declination (D), was from 6° 18′.9 W to 6° 14′.9 W, followed by a sudden change to 6° 37′ W. The recording spot left the sheet at 2h 56m, at the value 7° 18′ W. and returned at 3h 28m, the maximum having occurred during this interval, probably reaching 7° 38′ W.
Concerning procedure at magnetic observatories
Authors: Chree C.
Published: February 2008

If I rightly follow Mr. Hazard (pages 145–148), the diurnal inequalities published of late years at the observatories of the United States Coast and Geodetic Survey for the five quiet days a month are derived from 24‐hour periods which commence at 0h G.M.T. of the international quiet days; also an approximate correction has been applied for non‐cyclic change. This is so far satisfactory. But I venture to express a hope that an exact, not an approximate, non‐cyclic correction may be applied in future, and that it will be extended to all diurnal inequalities.

For those who have no fondness for mental arithmetic, I would recommend the use of a table of non‐cyclic corrections. Using a table, it is just as easy to apply the exact correction at each hour to the nearest 0.01 or 0.1, as the case may be, as it is to apply the approximate correction described by Mr. Hazard. The use of zonal time instead of L.M.T. is obviously advantageous for international term days. It has always been the practice for such purposes to use G.M.T. at all the British magnetic observatories. It undoubtedly facilitates the intercomparison of curves. When diurnal inequalities are analyzed in Fourier series, there are advantages in referring the phase angles to local time. But the difference between the phase angles calculated for Local and Greenwich time is constant, being determined by the difference of longitude. Thus the phase angles referred to local time can be derived at once from those calculated using Greenwich or Zonal time.
Values of the magnetic elements at the observatories of the United States Coast and Geodetic Survey at the time of the solar eclipse of May 29, 1919
Authors: Hazard D. L.
Published: February 2008

In order to supply data for a comparison of the magnetic condition of the Earth within and outside the eclipse belt at the time of the solar eclipse of May 29, 1919, values of the declination, horizontal intensity and vertical intensity have been derived from the magnetograms of the five magnetic observatories of the United States Coast and Geodetic Survey for every five minutes of the period from 10h to 16h30m Greenwich mean time. In reading the ordinates a graphical integration was made, so that a tabular value is approximately the average value for the 5‐minute period of which the tabular time is in the middle.

Tables are given showing the diurnal variation of the magnetic elements for selected quiet days: May 29 to June 7 for Puerto Rico, Cheltenham and Sitka; May 28–30, June 1–7 for Tucson; May 27–31 for declination and vertical intensity, and May 8, 16, 29, 30, 31 for horizontal intensity for Honolulu. A plus sign indicates eastward deflection of the north end of the needle, or increasing intensity.
Observations in the Azores, May 28–30, 1919
Authors: Chaves Col. F. A.
Published: February 2008

Special magnetic observations were made in this Island of S. Miguel (Azores) during the solar eclipse of May 29, 1919, in accordance with the program of the Department of Terrestrial Magnetism.

In the garden of my house I have, since 1899, a pier on which I make absolute measurements of the magnetic elements, to compare with those observed at the Magnetic Observatory of S. Miguel, established near Ponta Delgada, under my general direction. In this garden I have also a Mascart declinometer, with which on May 29, during the interval of 9h 58m to 16h 32m, Greenwich civil mean time, were made at every minute observations of the declination. Since the results of these eye‐readings of the declination agree perfectly with those of the eye‐readings, made with a similar instrument at the Magnetic Observatory, only the results of the latter observations are given here. [Table 1 contains the five‐minute means.]
Magnetic observations at Pilar, May 28–30, 1919
Authors: Bigelow F. H.
Published: February 2008

Table 1 contains for the Pilar Magnetic Observatory, Argentina, the five‐minute means of magnetic declination, D, derived from the magnetometer values for every minute from 9h 58m to 16h 32m, Greenwich civil mean time May 29, 1919, and of the corresponding magnetograph values on May 28 and 30, all referred to the mean base‐line 7° 35′.92. The bracketted quantities indicate that occasionally one (or more) of the single‐minute values of the five, from which the mean was to be taken, was missed. At 14h 49m, G. M. T., May 30, the base‐line was displaced +1′.0 by an earthquake, and the corrected base‐line of 7° 36′.92 was used accordingly, to reduce the subsequent readings.

The geographic coordinates are: latitude, 31° 40′ S.; longitude, 63° 53′ or 4h 15m.5 W. [Besides the magnetic observations complete meteorological data for May 28–30, as also solar‐radiation observations for May 28 and 29, were supplied. — Ed.]
Magnetic observations at Antipolo, May 29, 1919
Authors: Masó M. Saderra
Published: February 2008

The values of H (horizontal intensity) and of Z (vertical intensity), given in Table 1, have been corrected for the range in temperature in the magnetograph room. May 29 was one of the quietest days (magnetic character 0). The values of the magnetic elements follow very closely the normal diurnal variation.

Before the prescribed observation‐hours the weather remained irregularly, cloudy and calm, with lightning in different directions. The air temperatures are tabulated for each hour.
Magnetic observations at Valencia, May 29, 1919
Authors: Dines L. H. G.
Published: February 2008

A temporary declinometer was erected in the basement of the Valencia Observatory at Cahirciveen, Ireland, and readings were taken from it every minute from 9h 58m to 16h 50m, G. M. T., May 29, 1919. [Table 1 contains the five‐minute means derived from these observations.] The chronometer used is regularly verified several times per week by a direct time signal from Greenwich, and by allowing for the error at the time, the readings of the declinometer were taken at each exact minute G. M. T. It is not at likely that there was any systematic error greater than ±2 s.
On vertical electric currents and the relation between terrestrial magnetism and atmospheric electricity
Authors: Bauer Louis A.
Published: February 2008

1. To what extent the magnetic forces as observed on the surface of the Earth can be referred to a potential, is a subject of paramount interest. The solution of the problem is of great importance, both as regards the constitution of the so‐called permanent magnetic field of the Earth and the systems giving rise to the manifold variations to which the terrestrial magnetic field is continually subject.

2. Any electric currents circulating above or below the Earth's surface in concentric layers, i. e., parallel to the surface, will give rise to magnetic forces which may be represented by a potential. Electric currents, on the other hand, cutting the Earth's surface, produce, in general, a mixed magnetic system: the horizontal components of such currents give rise to a magnetic potential, whereas, the vertical components cause magnetic forces which cannot be referred to a potential. As is well known, the test of the existence of a potential is the vanishing of the line‐integral of the magnetic force taken around a closed curve, or circuit, on the Earth's surface. If the line‐integral does not vanish and its departure from zero cannot be explained by error of observation, or local magnetic disturbances in the region of the circuit, then the existence of a non‐potential is revealed; from the magnitude and sign of the integral we may then determine the strength and direction of the electric currents passing perpendicularly through the surface of the region enclosed by the circuit.
R. De Eötvös' law concerning the connection between the local disturbances of the magnetic force and those of gravity
Authors: Steiner L.
Published: February 2008

1. As to the origin of the local magnetic disturbances, there are two predominant opinions: The one considers the disturbances of the earth‐currents, produced by irregularities in the structure of the Earth's crust, as the main cause; the other concept supposes that magnetization, induced in rocks by the permanent field of the Earth, is chiefly responsible for the local magnetic disturbances. In the latter concept, too, the structure of the Earth's crust is of eminent importance. The distribution of the diverse magnetizable rocks, or an abrupt change in their arrangement as, for instance, is found along with tectonic lines, may manifest themselves in local magnetic disturbances. This idea has largely been applied by Rücker and Thorpe in interpreting the disturbances disclosed by their magnetic survey of the British Isles.
Preliminary results of ocean magnetic observations on the Carnegie from Apia to Balboa and Washington, July‐November, 1921
Authors: Ault J. P.
Published: February 2008

NOTES ON TRIP FROM APIA, SAMOA, TO BALBOA, CANAL ZONE.

We sailed from Apia in the afternoon of July 25, 1921, and upon rounding the Island of Savaii found the wind to the north of east which enabled us to weather the Tonga Islands. Light winds and calms prevailed for the first twelve days during which the average daily run was only 75 miles. The engine was used for 95 hours between July 25 and August 6.