bluuebunny/crossref_metadata_2025 huggingface dataset:
Second international seismological conference at Strassburg
Authors: Reid Harry Fielding
Published: February 2008

In response to a call from the German Government, delegates were appointed by various countries to meet in Strassburg, from July 24th to 28th of the present year, to discuss the organization of an International Seismological Association. Official delegates were present from the following nineteen countries, namely: Germany, Argentine Republic, Austria, Belgium, Bulgaria, Chili, Congo, United States, Great Britain, Hungary, Japan, Italy, Mexico, Holland, Portugal, Roumania, Russia, Sweden, and Switzerland. France and Spain also had representatives, but they did not come as official delegates.

The meetings took place in the main assembly‐room of the “Landesausschussgebäude,” and were opened by the Prince of Hohenlohe‐Langenburg, Imperial Governor of Alsace‐Lorraine. He made an address of welcome to the delegates, and was followed by Professor Dr. Gerland, the director of the Imperial Central Seismological Station at Strassburg, who also welcomed the delegates and stated the object of the meeting.
Record of the great magnetic storm of October 31, 1903, at Ponta Delgada, Azores
Authors: Chaves F. A.
Published: February 2008

The “Gauss” of the German Antartic expedition, arrived at Ponta Delgada, Azores, on October 28, 1903, on its return from the Antartic regions. On October 30th, Dr. Bidlingmaier, in charge of the magnetic work of this expedition, began to make magnetic observations at various points on St. Michael's Island. I, accordingly, took eye readings of the magnetic declination to supply the necessary reductions for his work. We both began at 7 A. M., local mean time.
A quartz‐thread vertical force magnetograph
Authors: Watson W.
Published: February 2008

The late Dr. Eschenhagen was the first to show that when the moment of inertia of the suspended system in a horizontal force magnetograph is made very much smaller than that employed in the ordinary form, it is possible to detect variations in the Earth's field of quick period. Since the study of these short‐period variations promises to be of considerable interest, the design of self‐recording instruments capable of giving satisfactory records becomes of importance. Both Dr. Eschenhagen2 and the author3 have described forms of apparatus suitable for recording the variations of the declination and horizontal component. The design of a satisfactory form of instrument to record the rapid variations of the vertical component presents, however, some very considerable difficulties.
Magnetic survey of the Dutch East Indies
Authors: van Bemmelen W.
Published: February 2008

The work of the survey has been continued during a trip round Sumatra lasting from February 19th till April 1st. Favored by the dry and clear weather prevailing on the northeastern coasts of Sumatra during this time of the year, the observations were as successful as could be wished.

The mode of observation was the same as in 1903; the storage battery apparatus with damping coil, lamp, and solenoid for reversing the polarity of the dip needles was kept in perfect working order throughout the whole trip, and has contributed in a remarkable manner to the success of the observations.
The physical decomposition of the earth's permanent magnetic field: No. V
Authors: Bauer L. A.
Published: February 2008

In the year 1634, as well known, an English mathematician, Gellibrand, announced his important discovery, that the direction assumed by a compass needle had undergone considerable change at London since the observation of Borough and Norman in 1580, when the needle had been found to point 11°1/4 East; in 1634 Gellibrand observed only a trifle over 4° East. Most commendably and remarkably for his time, he refrained from “entering into a dispute [speculation] concerning the source of this sensible diminution, whether it may be imputed to the magnet or the Earth or both,” but says it “must be all left to future times to discover, this Invention being but newly presented to the world in its infancy.”

Nearly three centuries have passed and Gellibrand's discovery has been amply verified. It has been found that not only the magnetic declination is subject to a secular change, but also the magnetic inclination and the intensity of the magnetic force. It is thus an accepted and a troublesome fact that the distribution of the Earth's magnetism undergoes considerable changes with the lapse of time. The cause of this secular change has been the subject of comparatively fruitless investigation of many noted physicists, mathematicians, and astronomers. Helmholtz characterized the Earth's magnetism as one of the most puzzling of natural forces and Maxwell in referring to the photographic records of the Earth's magnetic fluctuations obtained at magnetic observatories says: “On that paper the never resting heart of the Earth is now tracing in telegraphic symbols, which will one day be interpreted, a record of its pulsations and its flutterings, as well as of that slow but mighty working [the secular variation] which warns us that we must not suppose that the inner history of our planet is ended.” Judging from the mass of literature on the subject of the secular variation, the difficulty apparently has not been in finding a cause, but to prove which among the many assignable ones was the one.
The electrochemical equivalent of silver
Authors: Guthe K. E.
Published: February 2008

A preliminary account of the recent redetermination of the electrochemical equivalent of silver by Van Dijk and Kunst has been given in the “Proc. Roy. Acad., Amsterdam, Jan. 21, 1904,” and in the “Ann. Phys. Vol. 14, p. 569, 1904.” Van Dijk has now published the interesting details of the research.

The tangent galvanometer method was employed, a method which requires the accurate knowledge of the intensity of the horizontal component of the Earth's magnetic field. This was determined by means of a bifilar magnetometer, with wires 232 cms. long and 12.4 cms. apart. Great pains were taken to eliminate all possible errors, and the difficulties encountered clue to local magnetic influences in the instruments are fully described.
Records of seismographs in North America and the Hawiian Islands: No. II1
Authors: Reid Harry Fielding
Published: February 2008

The following table contains the records of seismographs in North America and the Hawaiian Islands for the second half of 1904. The times are Greenwich mean civil time beginning at midnight. The following abbreviations are used:

P. T. = preliminary tremors; P. P. = principal part, sometimes called long waves. The location of the stations, the type of instrument installed and the components of the motion registered are as follows:
The magnetic survey of the North Pacific Ocean: instruments, methods, and preliminary results
Authors: Bauer L. A.
Published: February 2008

As is well known, the Carnegie Institution of Washington authorized its Department of Terrestrial Magnetism to undertake a magnetic survey of the North Pacific Ocean, and made a provisional allotment of $20,000 to cover the initial costs of its inauguration and progress during the year 1905, in accordance with a plan submitted by Messrs. L. A. Bauer and G. W. Littlehales. [The allotment for 1906 has been sufficiently enlarged to permit the continuous and uninterrupted prosecution of the work, and ample assurance has been received of similar allotments, so that the systematic magnetic survey of the oceanic areas, not alone of the North Pacific Ocean, is now an assured fact.]

A single quotation will suffice to show that there were good grounds for the undertaking of an oceanic magnetic survey, and for beginning first of all with the Ocean, so rapidly developing in commercial importance—the North Pacific Ocean.
A direct recording declinograph
Authors: Cady W. G.
Published: February 2008

A preliminary paper on this instrument was published in this journal for June, 1904. (Vol. IX, p. 69.) Under the auspices of the Department of Terrestrial Magnetism of the Carnegie Institution two portable declinographs have since then been constructed under the writer's direction, one of which is at present installed at the Solar Observatory on Mt. Wilson, California. As these instruments embody several features not contained in the original experimental apparatus, a short description of them is here given.

It will be remembered that the principle of the instrument consists in the transmission of the movements of a suspended magnetic needle, through a delicate suspended glass lever to a pen situated at the end of a long arm. The lever system is therefore somewhat similar to that in the Bosch‐Omori seismograph, except that no pivots are used. The directive force acting on a magnetic needle in the Earth's field, is so much feebler than that in the case of a massive horizontal pendulum, that it was thought best to avoid the slight but uncertain friction of pivots. The pen is caused periodically to print a dot upon a long strip of paper, which is advanced by means of clockwork. The most radical departure from the original apparatus is in the manner of printing dots: the pen is no longer drawn down to the paper by means of a solenoid, but the paper is automatically lifted up so as to touch the pen. This avoids the danger of magnetic disturbances caused by having a solenoid plunger mounted on the pen arm, and also reduces the moment of inertia of the moving system to a minimum. Owing to the additional energy required to raise the paper as well as to advance it, this double function is performed by an electro‐magnet mounted at a suitable distance below the instrument. The clock that periodically closes the electric circuit may then be located at any distance from the instrument. Other changes and new features are described in the following paragraphs. With the exception of the enclosing cases and the clockwork, practically the entire work of construction was carried out by Mr. F. H. J. Newton, the college mechanician, to whose ingenuity and skill acknowledgement is here made.
Vorläufige Mitteilung über magnetische Variationsbeobachtungen in einem Bergwerk
Authors: Schmidt Ad.
Published: February 2008

Durch ein wesentlich den Herren Landesgeologen Professor Dr. Schneider und Professor Dr. Jentzsch zu verdankendes Zusammenwirken der Preussisehen Geologischen Landesanstalt und des Potsdamer Magnetischen Observatoriums ist es nach längeren Vorbereitungen gelungen, in einem Kohlenbergwerk in der Nähe von Dortmund (in Westfalen) für einige Zeit eine magnetische Doppelstation in Betrieb zu setzen, um die Frage zu entscheiden, ob die magnetischen Variationserscheinungen in den uns zugänglichen Tiefen im Erdinnern bereits merkbare Abweichungen von denjenigen an der Erdoberfläche zeigen.

Die Anlage befindet sich auf der der Gelsenkirchener Bergwerks‐Aktien‐Gesellschaft gehörigen Zeche Monopol und ist, von der instrumenteilen Ausrüstung und dem der Technischen Hochschule in Aachen gehörigen Beobachtungshäuschen abgesehen, von dieser Gesellschaft in dankenswerter Weise auf ihre Kosten hergestellt worden. Auch der Betrieb wird von ihr unterhalten. Die Instrumente hat Herr Mechaniker Schulze in Potsdam für diesen Zweck gebaut und ohne jede Entschädigung leihweise zur Verfügung gestellt, ein Entgegenkommen, das um so höher anzuerkennen ist, als das ganze Unternehmen dadurch überhaupt erst möglich gemacht wurde. Der Betrieb wird von Herrn Markscheider Stiepel geleitet, der zur Vorbereitung darauf im Frühjahr dieses Jahres vierzehn Tage am Potsdamer Observatorium gearbeitet hat.
Concerning pulsations of short period in the strength of the Earth's magnetic field
Authors: Ebert H.
Published: February 2008

For a considerable length of time a general interest has been aroused by the striking, regular oscillations of short period in the Earth's magnetic force which, at times of magnetic disturbances as well as at times of perfect magnetic calm, appear in the form of short waves, (“terrestrial magnetic waves”), in the magnetograph curves.

Lamont observed such pulsations,2 a fact which is to be noted because at that time there as yet existed no strong artificial electric currents of any sort whatever, and hence the oscillations mentioned must certainly have been caused by the Earth's field.
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory
Authors: Burbank J. E. , Tittmann O. H.
Published: February 2008

January 1—March 31, 1907.
Magnetic observations during partial solar eclipse, January 13, 1907, at Zi‐Ka‐Wei
Authors: de Moidrey J.
Published: February 2008

On the occasion of the partial eclipse of the Sun, January 13, 1907, which here reached a magnitude of nearly 0.6, we exercised more than usual care in the registration.

Scale value determinations were made at two distances in the morning; the time was marked with precision at the beginning and ending.
Preliminary report on atmospheric electricity work, yacht “Galilee,” Sitka to Honolulu, August, 1907
Authors: Dike P. H.
Published: February 2008

On unpacking the instruments at Sitka it was found that the leaves of three of the electroscopes were damaged, making necessary to put in new leaves and to recalibrate the electroscopes. Some trouble was encountered in the calibration, due to the leakage between the poles of the battery of small cells constructed at the Office in Washington, which was overcome by removing all the parafine surrounding the cells. The work of calibration took so much time that there was no opportunity for observations in port, nor for observations on land to determine the influence of the ship on the results, these being especially desirable in the case of the potential work.

The extra gimbal stand was mounted on the forecastle beneath the bridge. Lead weights were added, in addition to the brass ball to balance the Gerdien conductivity apparatus, when mounted on the gimbal stand on the low tripod purchased for the purpose. The Ebert ion‐counter was also fitted to be mounted on the same tripod.
The penetrating radiation
Authors: Strong W. W.
Published: February 2008

In the present article three distinct methods will be given to show that the penetrating radiation which produces part of the ionization in closed vessels is not due to γ rays from radium in the ground itself. It seems quite probable that the penetrating radiation must be due to radioactive products in the air and it is quite probable that the origin of these products is in the ground as Elster and Geitel's theory indicates.

The first method is based upon the radium content of the various rocks as analyzed by Strutt and Eve. The highest value for the radium content of sedimentary rocks was found to be 2.92 (10)−12 grams of radium per gram of rock. The mean value found by Strutt for sedimentary rocks was 1.1 (10)−12 grams and by Eve 0.8 (10)−12 gram. The value of the radium content varies greatly with the locality, but for surface soils which are subjected to all the various kinds of weather changes the radium content is probably smaller than that found above. For instance Strutt found a radium content for chalk at the bottom of a cliff to be 0.39 (10)−12 gram and at the top of the same cliff 0.12 (10)−12 gram.
Return of the “Galilee” and construction of a special vessel
Authors: Bauer L. A.
Published: February 2008

The yacht “Galilee” chartered by the Department Terrestrial Magnetism of the Carnegie Institution of Washington, for the purpose of a general or preliminary magnetic survey of the Pacific Ocean, returned to her home port, San Francisco, California, on May 22, after an absence of nearty three years, during which she has cruised in the Pacific Ocean to the extent of about 65,000 nautical miles.

After completing at San Francisco various swings and observations, she left on August 4, 1905, for a trial cruise to San Diego, California, under the writer's direction for the purpose of completing the necessary training of the observers and perfecting the methods of observation. The vessel next proceeded to Honolulu and Fanning Island, returning to San Diego, California, in December, 1905. Captain J. F. Pratt of the United States Coast and Geodetic Survey commanded the vessel in 1905. Upon the expiration of his furlough, Mr. W. J. Peters, chief magnetic observer of the Department Terrestrial Magnetism, assumed command and carried out the balance of the cruises up to the return to San Francisco in a most satisfactory manner.
Solar magnetic fields and the cause of terrestrial magnetism
Authors: Sutherland William
Published: February 2008

In this JOURNAL for June, 1900 (vol. V, p. 73), June, 1903 (vol. VIII, p. 49) and December, 1904 (vol. IX, p. 167), the Earth's magnetism was traced to rotation round the axis, different hypotheses for a differential effect resulting from the two kinds of electricity being discussed in each of the three papers. As the formulae of these papers should apply to all heavenly bodies, the best way of testing them would be to compare their results with the facts of observation in other planets or in stars. Hitherto these facts have been almost wanting except for the inference of Bigelow that the Sun has a magnetic field related to its axis of rotation but somewhat asymmetrically, just as in the case of the Earth.

But a new era in astronomical magnetism is opened by the discovery of Hale that the solar vortices associated with Sun‐spots produce just such a separation of a spectral line into two as is known in the laboratory as the “Zeeman effect” when produced by a magnetic field. The only account yet available to me of this discovery is that given in “Nature” August 20, 1908, p. 368, followed by a comment from Zeeman, p. 369, but I hasten to show its bearing on the theory of stellar magnetism.1
L'Observatoire magnétique de Zi‐Ka‐Wei
Authors: de Moidrey J.
Published: February 2008

Le service magnétique de l'Observatoire de Zi‐ka‐wei a été établi, sur les conseils de l'illustre P. Angelo Secchi, par le P. Marc Dechevrens, en 1874, époque où l'observatoire magnétique le plus oriental était celui de Batavia. Le P. Dechevrens était muni d'un magnétomètre du modèle de Kew et d'un cercle d'inclinaison du type classique. Les premières observations qu'il a publiées sont datées du 23 mars 1874.

Bientôt, avec l'aide du P. Perry, de Stonyhurst, il faisait construire par Adie un enregistreur photographique, qui fut vérifié en Angleterre et installé dans un pavillon spécial dont nous donnons une vue. L'enregistrement commenca en 1877. Depuis le 1 mars de cette année, les bulletins donnent, d'heure en heure, la valeur de la déclinaison et des deux composantes de la force. La continuité de cette série n'est rompue que par deux interruptions, l'une de juin à septembre 1878, l'autre en février 1889, toutes deux nécessitées par des agrandissements ou des réparations de la salle.
Does magnetization alter mass?
Authors: Lloyd Morton G.
Published: February 2008

In a paper giving the results of some weighings of magnets, Dr. L. A. Bauer has raised the question as to whether magnetization alters mass. His observations were made upon bar magnets, in both the magnetized and demagnetized state, and in various orientations with respect to the Earth's field. It is obvious that if there be local disturbances of the field, the weighings may give different results for different positions of the magnet, since it is not simply the force of gravitation which is being measured, but in addition the magnetic forces which act upon the bar.

Such a specimen is well suited to the purpose of determining whether the magnetic forces have any translational resultant, (and this was the primary object of the experiments cited above) but it is very ill suited to the purpose of determining whether the gravitational force alone is constant. For this purpose it is desirable to have a specimen forming a closed magnetic circuit, and hence without poles, so that there will be no action upon it by the Earth's field. Such a specimen can be put in the same magnetic condition as a bar, and hence any change in the Earth's gravitational action upon it would be equally apparent, while at the same time the extraneous magnetic forces, which complicate the experiment with the bar, are absent.
Birkeland's theory of magnetic storms and terrestrial magnetism
Authors: Humphreys W. J.
Published: February 2008

Since the days of Oersted's discovery of the deflecting effect of an electric current on a magnetic needle and Ampère's investigations of this phenomenon, there has been an impression among physicists that the relation between electricity and magnetism must be an extremely intimate one: an impression which discovery after discovery has so confirmed that today we feel justified in saying that this relation is one of cause and effect and that all magnetic fields are due to electric currents and that these consist of moving electric charges.

If then this is the fundamental relation between electricity and magnetism, if there can be no magnetic field except that which is due to an electric current, it follows that our magnetic storms must be caused by correspondingly fleeting and irregular electric currents whose origin and laws are to be determined only by analysis and experiment: analysis of extensive observations supplemented by confirmatory evidence in the laboratory. This is the kind of evidence presented in the book under discussion, and while the author does not claim to have solved the problem in all its details, still so much has been done, and done so well, that no one interested in the study of magnetic storms can afford to be without it.
The non‐magnetic gas engine of the “Carnegie”
Authors: Craig James
Published: February 2008

The construction of the non‐magnetic vessel, “Carnegie”, for the Carnegie Institution of Washington, to be engaged in ocean magnetic surveys, presented various interesting mechanical problems. Especially so when it was decided to equip the vessel—primarily a sailing one—with sufficient auxiliary power to drive her, in calm weather, at a speed of about six knots.

Of the various types of motors available—steam, gasoline, gas producer—investigations made by the architect of the vessel, Mr. Henry J. Gielow, of New York City, first with regard to the initial cost from a non‐magnetic standpoint; secondly, as to cost of maintainance, and thirdly, with reference to the possibility of obtaining practically everywhere the fuel to be used, resulted in the selection of the third type.
Some of the problems of ocean magnetic work
Authors: Bauer L. A.
Published: February 2008

From the very start of the ocean magnetic work on the “Galilee” in 1905, two principles have been steadfastly held in view:

a. To get useful work done and make the results promptly known.

b. To strive towards the highest accuracy attainable, in all elements, consistent with a.
Northern lights in the North Pacific Ocean Sept. 23, 1909
Authors: Beeb Pheovan
Published: February 2008

Sept. 25th, 1909 at 3 A.M.; Latitude 51°16′ N., longitude 134°40′ West of Greenwich.

A whitish sheet of light appeared in the northwest horizon, extending from the star Vega (setting) through Ursae Majoris. This was followed by shafts of light about 2° or 3° in width, appearing simultaneously in the eastern and western horizon, finally creeping up and meeting an the south, passing sometimes through the constellation of Orion, covering the planet Saturn and passing north of Mars, at other times passing through Sirius and covering or extending south of Mars, imparting a marked brilliancy to said and neighboring stars. After 4:00 A.M. Northern Lights appeared from north to east of a reddish and green hue, assuming rainbow colors at times. Barometer was 30.04 inches; air 50°, wet bulb 47°, water 50° Fahrenheit.
Magnetic storm of Sept. 25, 1909, as observed at Washington, D.C.
Authors: Fisk H. W.
Published: February 2008

By a fortunate chance I went on the morning of September 25 to one of the small non‐magnetic houses used for testing instruments, belonging to the Department of Terrestrial Magnetism. My purpose was to test the magnetization of some compass needles, using the deflection method and working with magnetometer, C I. No. 3. After the first round of deflections at two distances, I found so large a disagreement in the means that I repeated a setting at a suspected position and obtained a very different reading which made the disagreement much worse! This drew my attention to the behavior of the suspended magnet, which I watched for some 12 minutes (10h 20m to 10h 32m 75 M. M. T.) during which time a movement of more than 18′ was noted, but it was apparent from the character of the movements that the suspended magnet, which had a small magnetic moment and a high moment of inertia, being loaded with a collimating tube, that much of the detail of the activity was lost, while the violence of the movements indicated a storm of unusual proportions. I then inserted the regular magnet (3L) used for oscillations and declinations and made readings at intervals as short as possible—usually 30 seconds—from 10h 34m to 11h 20m, after which time the violence had mostly subsided, although the disturbance still in progress would have been called unusual, at any other time.
Time and direction at the poles of the Earth
Authors: Peters W. J.
Published: February 2008

Now that the polar discoveries in both hemispheres are attracting so much public attention it may be interesting to refer briefly to the astronomic problems of time and direction at the true Poles. It is often said that there is no time of day at these points, and that every direction in the horizon is south from the North Pole and north from the South Pole. While these statements are strictly true, they do not imply there is no definite direction or that time is indeterminate.

Suppose our explorer with his watch running on Greenwich time arrives at one of the Poles on the twenty‐first of March. About this date the Sun is moving in the horizon. At Greenwich apparent noon it appears exactly in the direction of Greenwich and the direction of any other place can be found by laying off its Greenwich longitude so many degrees to the right or left of the Sun at this instant. Or he may convert this longitude into apparent Greenwich time and his watch will show when the Sun has reached the direction in which he wishes to travel. If the Sun is much above the horizon the method will be the same if a theodolite or similar instrument is at hand. With a sextant only, some calculation might be necessary for more accurate determination. If the Sun is below the horizon it is either moonlight, twilight, or dark, and stars can then be used in practically the same way.
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory
Authors: Tittmann O. H. , Burbank J. E.
Published: February 2008

In the September (1907) number of this journal (Vol. XII, No. 4, page 184) it was stated that the Baldwin magnetic observatory of the United States Coast and Geodetic Survey would be kept in operation until another magnetic observatory could be established somewhere west of the Mississippi River to replace it.

During the early part of 1909 a site for a magnetic observatory was selected in the vicinity of Tucson, in the Territory of Arizona, after a careful inspection had been made of a number of possible locations, and after a magnetic survey was made of the finally adopted location. Construction work on the observatory buildings began in the latter part of June, 1909, and the buildings were ready for the installation of the magnetic instruments by the first of November, 1909.
Observations of Earth‐currents in Stockholm on May 19, 1910, during passage of Halley's Comet
Authors: Stenqvist D. , Petri E.
Published: February 2008

During the transit of Halley's comet across the Sun's disc on May 19, 1910, magnetic observations were made, on the initiative chiefly of Prof. Birkeland, at several places of the globe. The authors thought it, therefore, not uninteresting to have earth‐current observations in this connection made at the Central Telegraph station in Stockholm. Two telegraph lines belonging to the Royal Swedish Telegraph Office, Stockholm ‐ Göteborg and Sundsvall ‐ Stockholm, were used. The geographic co‐ordinates for these three places are as follows:Table I. LATITUDE LONGITUDEStockholm . . . . 59° 21′ 18° 3′Göteborg . . . . . 57 42 11 58Sundsvall . . . . 62 23 17 19
Die erdmagnetischen Elemente in Apia, 1905–08
Authors: Angenheister G.
Published: February 2008

Im Bezug, auf meinen Artikel in Terr. Mag. XV, pp. 169–172, teile ich Ihnen folgendes mit:

Bei einer nochmaligen Durchsicht der Horizontal‐Intensität Beobachtungen hat sich ein Additionsfehler vorgefunden, nämlich bei den Monatsmittel Dezember 1906, statt 0.35676 muss es heissen 0.35646; infolgedessen auch das Jahresmittel für 1906 von 0.35658 auf 0.35655, sowie das für 1908 von 0.35616 auf 0.35613 zu ändern ist.
The peculiar magnetic disturbances of December 28–31, 1908
Authors: Faris R. L.
Published: February 2008

In the March, 1909, number of this Journal,2 Mr. D. L. Hazard called attention to the peculiar features of some magnetic disturbances which occurred on December 29 and 30, 1908, and described their characteristics as shown on the records of the Cheltenham Observatory, comparison also being made of their features as recorded at the other observatories of the Coast and Geodetic Survey. These disturbances being of such special interest, occurring as they did, as definite perturbations of about half an hour's duration during a period when the magnetic conditions were everywhere exceptionally quiet, it was suggested by Dr. L. A. Bauer that it would be worth while to examine the records of other observatories in order to ascertain if similar disturbances were recorded in other parts of the world. Accordingly, with this point in view, many of the observatories were asked to supply the desired data as outlined in the following extract from the letter of the Superintendent of the Coast and Geodetic Survey, Mr. O. H. Tittmann, under date of May 21, 1910, addressed to the directors of various magnetic institutions:

Dear Sir: Will you please forward to me at your earliest convenience, for the use of the Division of Terrestrial Magnetism, copies of your photomagnetic curves (magnetograms) covering the period front the beginning of December 29th to the end of December 31st, Greenwich civil date, 1908, with all the necessary data for reading the ordinates and converting them into absolute measure. In order to serve as a check on our own readings, please send also your hourly readings for these days, and the mean hourly values for the entire month.
The physical theory of the Earth's magnetic and electric phenomena.—No. IV: On the origin of the Earth's magnetism
Authors: Bauer L. A.
Published: February 2008

42. In the previous number, the hypothesis was set up (§29) that “the Earth is chiefly an electromagnet, the magnetizing currents being outside and consisting of negative electric currents circulating overhead in the same general direction as that of the Earth's rotation, namely, from west to east.” The external currents are revealed by the harmonic analysis of the magnetic elements observed on the Earth's surface (§37). Starting with these currents, it was found that, qualitatively, the Earth, if paramagnetic, would be magnetized by them in the general direction in which it is actually found to be and that quantitatively, the magnetization of our planet can be accounted for, if its average magnetic permeability is on the order of 135 for a magnetizing force of about 0.0024 C. G. S. This value while high was shown not to be impossible and, in fact, it is not as great as has been thought necessary in order to account for the Earth's magnetism electromagnetically; as these researches progress it is quite likely that the value will receive some modification.
Results of magnetic observations made by the United States Coast and Geodetic Survey at the time of the solar eclipse of April 28, 1911
Authors: Tittmann O. H.
Published: February 2008

With a view to furnishing additional data for the study of the effect of an eclipse of the Sun upon the Earth's magnetism, the observers in charge of the magnetic observatories of the Coast and Geodetic Survey were directed to be sure that the magnetographs were in good working order at the time of the solar eclipse of April 28, 1911, and to make declination observations every fifteen minutes for a period of six hours, including the eclipse. The observations were made in response to a request for cooperative work received from Dr. L. A. Bauer.

The observatories are all supplied with magnetographs of the Eschenhagen type. The instrument rooms are so well insulated that the temperature seldom changes more than two or three‐tenths of a degree Centigrade in the course of a day, and the effect of change of temperature on the magnets could therefore be neglected for the period covered by the eclipse.
Magnetic declinations and chart corrections in the Indian Ocean—Continued
Authors: Bauer L. A. , Peters W. J.
Published: February 2008

The present tables Nos. 4 and 5, contain the results for magnetic declination obtained on board the Carnegie from Mauritius to Colombo, August 16 to September 10, 1911, and from Colombo to Batavia, September 16 to October 26, 1911. The same statements and conventions apply as for the previous tables, Nos. 1, 2, and 3 in the September, 1911, issue of the Journal (Vol. XVI, p. 133), except that instead of the word “errors” used before, the more proper term “corrections ” is now applied, thus conforming with the earlier article (Vol. XV, p. 143).

The present results will assist materially in locating correctly the‐agonic line in the Arabian Sea and in the Bay of Bengal.
Levé magnétique du bassin du Rio S. Francisco
Authors: Morize H.
Published: February 2008

J'ai l'honneur de vous envoyer les résultats obtenus par l'expédition magnétique que j'ai envoyé renouveler le levé effectué, en 1883, par le Dr. van Ryckevorsel, dans le bassin du Rio S. Francisco.

L'expédition était composée de M. Domingos Costa, Assistant de le classe, comme chef, et de M. Luiz Rodrigues, Assistant de 3e classe, comme auxiliaire. Elle partit de Rio et commença ses travaux à Barra do Pirahy, le 26 Octobre 1910, et pousuivit ensuite, jusqu'à. la fin de Septembre de l'année suivante, l'itinéraire de Ia Commission Hollandaise. Toutes les localités reconnaissables furent réoccupées, moins quelques unes sur le Rio‐das‐Velhas, où plusieurs points durent être abandonnés, à cause de l'éloignement de la ligne de chemin de fer actuel, par rapport à l'ancienne route suivie par M. van Ryckevorsel.
Observation of the magnetic declination at Warsaw during the solar eclipse of April 17, 1912
Authors: Kalinowski S.
Published: February 2008

In want of a magnetograph I employed for this purpose the Kew pattern magnetometer of the Cambridge Scientific Instrument Co. This instrument is used also for my systematic researches in terrestrial magnetism in Poland.

I made my observations during a few days at precisely the same point in the racing field at a distance of about 0.5 km. from the electric tramway line.
Preliminary note on an attempt to detect the general magnetic field of the Sun
Authors: Hale George E.
Published: February 2008

In 1908, shortly after magnetic fields had been found in Sunspots, an attempt was made to observe the Zeeman effect due to the general magnetic field of the Sun with the 60‐foot tower telescope and 30‐foot spectrograph of the Mount Wilson Solar Observatory. Although slight shifts of certain solar lines, such as might be caused by. a magnetic field, were found on measuring the photographs, the quantities. were too small to command confidence, and the work was postponed until more perfect polarizing apparatus could be provided.

The investigation was resumed in October, 1911, but no certain evidences of the Zeeman effect were detected. On the completion of the 150‐foot tower telescope and 75‐foot spectrograph, observations were begun with .this instrument in January of the present year, The objective of 150 feet focal length now used with this telescope was not then ready, and, accordingly, the 12‐inch objective of 60 feet focal length, belonging to the 60‐foot tower telescope, was temporarily transferred to the new tower. This forms. an image of the Sun 6.7 inches in diameter on the slit of the spectrograph. After passing through the slit the light descends vertically into a well, excavated in the earth beneath the tower, to a depth of 75 feet, where it falls upon the objective which serves for both collimator and camera of the auto‐collimating spectrograph. We were fortunate in having a large grating of the finest quality, ruled by Michelson, which gives almost theoretical resolution in the third order spectrum. Here the scale is 4.9 mm to the Ängström unit, corresponding to a distance of 29 mm between the D lines.
Description of the C. I. W. Marine Earth Inductor
Authors: Fleming J. A.
Published: February 2008

One of the problems encountered in ocean magnetic work covering an extensive area has been that of the satisfactory determination of the variations in the reductions of dip observations to standard with change in magnetic latitude. The problem has been the more difficult because of the mechanical impossibility, despite the most skillful and careful workmanship, of producing a perfect axle. Up to the present time the corrections on standard have been obtained with the aid of the observations at the ports visited where intercomparisons were secured between a standardized earth inductor and the dip circles employed at sea. As these stations are often widely separated and as the conditions aboard ship, where the instruments and needles are in constant motion, are so very different from those on shore, it became desirable that some form of instrument should be devised for the purpose of securing standardizations and the required control on board ship, i. e., in transit from port to port.
Report on the C. I. W. Marine Earth Inductor
Authors: Hewlett C. W.
Published: February 2008

The apparatus was installed on board the Carnegie at Papeete, Tahiti, in October, 1912, as follows: The inductor was mounted on the new gimbal stand (Plate I, Fig. 1) in the after observatory, C1; the galvanometer, in order to eliminate any possible magnetic effect, was fastened by a bolt passing through the hard rubber base of the instrument to a substantial shelf against a wood wall about thirty feet aft of the inductor; communication between the observers at the earth inductor and the galvanometer was established by means of a simple signaling device. The writer, after having taken part in the experimental work at Washington, was assigned as observer on board the Carnegie and was placed in charge of the earth‐inductor work by Mr. Peters, in command of the vessel, who afforded him every possible facility.

The chief difficulty at sea has been the maintenance of the adjustment of the galvanometer, owing to some minor imperfections which can easily be remedied.2 It has been found possible to adjust readily the system at shore stations so that a tip of 20° in .any direction, with a scale distance of 58 cm., causes a change of not more than 1 mm. in the galvanometer zero. The failure to maintain balance at sea is also partly due to the temperature and humidity changes. Fortunately, after some practice, it has been found possible to make the adjustment for balance on board, even when the sea is moderately rough, within three to fifteen minutes, depending upon how badly the coil was out of balance and upon the character of the ship's motion. In moderately rough seas, the wandering of the zero is reduced to a range of 5 to 10 mm. when the galvanometer is used with a 100‐ohm shunt. Owing to the lack of symmetry in the balancing arrangements, it is difficult to throw the center of gravity of the coil into the line of suspension. By manipulation, it has been found easier to place the center of gravity in a plane at right angles to the coil than in the plane of the coil; for this reason the galvanometer has been mounted with the plane of its coil fore and aft.
A new universal magnetic theodolite for determining the declination, and the horizontal and vertical intensities
Authors: Ogloblinsky N.
Published: February 2008

Ten years ago it occurred to me to apply some of the principles underlying the determination of the magnetic forces on board, adopted in the Russian Imperial Navy, to the direct measurement of the horizontal intensity H and the vertical intensity Z, with land instruments. Accordingly, in 1909 there were prepared the designs of a new theodolite for the determination of H and Z as well as of the declination, D, and for astronomical work. During the years 1910 and 1911 the instrument was constructed in the workshops of the General Hydrographic Office under the supervision of the chief of the shops, Mr. Heinrich Freiberg, the well‐known mechanician and collaborator of the late Heinrich Wild.

The first tests of the new theodolite in Pavlovsk at the Constantin Observatory in 1911 and especially in a magnetic survey along the shores of the Bay of Finland, near Cronstadt in 1912, under severe conditions, gave satisfactory results. I was thus led to think that the proposed method might be applied to advantage in land magnetic survey work and even in observatory work.
Practical processes for producing the best permanent magnets
Authors: Thompson Silvanus P.
Published: February 2008

To produce permanent magnets, which are both powerful and constant in their power, a tungsten steel should be used having from 5 to 8 per cent of tungsten, and from 0.4 to 0.6 of carbon. Chromium up to 2 or 2.5 per cent may be present, but the presence of the following elements should be avoided: manganese, titanium, copper, sulphur, and phosphorus.

For bar magnets there is an advantage in having the dimension‐ratio as large as possible, as this gives not only a higher remanence, but a lower coefficient of temperature variation. For horse‐shoe magnets, and for all those which are to be used in instruments where extreme constancy is required, the gap between the poles should be as short as possible, and the polar areas should be as large as possible. From the, point of view of constancy there is an advantage in having a considerable stray flux (through a magnetic shunt or otherwise) in addition to the useful flux.
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July 1 to December 1, 1913
Authors: Hartnell George , Tittmann O. H.
Published: February 2008

For the last quarter of 1913 Cheltenham reports “No storms during this period,” and Tucson reports “A period free from pronounced disturbances.”
Results of magnetic observations by the Charcot Antarctic Expedition, 1903–1905
Authors: Palmer A. H.
Published: February 2008

The expedition was not provided with the magnetic apparatus usually associated with a magnetic station of importance. The instruments consisted only of (1) a Brunner theodolite, large model, and (2) an inclination compass, small model. Designed only with a view of determining the absolute values of the magnetic elements, these instruments, though satisfactory for work in temperate latitudes, proved to be insufficient and ill adapted for use under the conditions prevailing in polar regions. Because of the unsatisfactory apparatus and the difficulties encountered extensive results were not possible.
Investigation of certain causes responsible for uncertainty in the measurement of atmospheric conductivity by the Gerdien conductivity apparatus
Authors: Hewlett C. W.
Published: February 2008

One of the most convenient methods of measuring the atmospheric conductivity is that due to Gerdien. In this method a stream of air is drawn through the space between two concentric cylinders, the inner one of which is charged. By observing the fall of potential of the inner cylinder in a known time, it becomes possible to calculate the conductivity due to those ions which are of opposite sign to the charge on this cylinder. Since the theory of the instrument, as worked out by Gerdien, postulates certain conditions which are not always fulfilled, it becomes desirable to see how far violation of these conditions is likely to affect the results; this is especially so since the apparatus in its usual form is of a convenient general design, is easily transportable, comparatively simple in its action, and is adaptable to measurements of conductivity of both signs.
Umbau an dem schulze'schen D‐Variometer des Observatoriums in Tsingtau
Authors: Meyermann B.
Published: February 2008

Das D‐Variometer des hiesigen Observatoriums besitzt die in Fig. 1 schematisch gegebene Optik. L ist die Linse, die den Spalt der Registrierlampe auf die Walze abbildet, B der feste Basis‐Spiegel, S der sich mit der Nadel bewegende Spiegel, P zwei übereinander stehende Prismen, die getrennt von aussen justiert werden können. Der Gang der Lichtstrahlen ist aus der Figur zu ersehen. Die Brennweite der Linse ist so gewählt, dass auf dem Papiere 1 mm. einem dD von einer Bogenmlnute entspricht. In dY umgerechnet ist dies für Tsingtau rund 8.95γ.
Reduction of the magnetic observatory work of the Australasian Antarctic Expedition, 1912–1913
Authors: Webb Eric N.
Published: February 2008

At the request of Sir Douglas Mawson, the undersigned has undertaken the reduction of the magnetograms obtained during the occupation of Adelie Land by the Australasian Antarctic Expedition in 1912–1913. The work is now well in hand at the address below, and it is hoped to have final values tabulated, and most material ready for discussion at the end of the current year.

Various observatories were requested to cooperate with the Expedition in the taking of “quick run” records at prearranged times. In order that the intercomparison of these curves may be as complete as possible, it is desired to collect copies of at least the most promising of them, and any details of the others that may be worth consideration. We should therefore be under considerable obligation for the forwarding, at the earliest convenience, of copies of “quick runs” at the following Greenwich mean times, wherever possible giving particulars of baselines and of scale values: G.M.T. G.M.T.April 16, 1912 8–10 A. M. April 18, 1912 5–7 P. M.May 14, 1912 8–10 A. M. October 10, 1912 5–7 P. M.June 11, 1912 8–10 A. M. January 2, 1913 5–7 P. M.July 16, 1912 8–10 A. M.October 8, 1912 8–10 A. M.
The magnetic character of the year 1914
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1914 has been drawn up in the same manner as for the preceding years. Forty‐three observatories contributed to the quarterly reviews; 38 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.
Record of lightning stroke at the magnetic observatory, Lukiapang, China, April 13, 1915
Authors: de Moidrey J.
Published: February 2008

On the morning of April 13, 1915, at 3h 34m, China coast time, lightning struck a tree 50 paces southwest of the magnetic hut. At so short a distance, the three self‐recording instruments were affected by the shock. In the case of the declinometer and the bifilar, there was an interruption of the tracing, then several minutes of oscillation—about 11′ and 9.8γ, respectively, or a little more, if it is assumed that the first oscillation made no impression on the sensitive paper. The Earth's magnetic field was therefore only slightly modified in direction and in horizontal intensity.
Preliminary report on the results of the aurora borealis expedition to Bossekop in the spring of 1913—Third communication
Authors: Störmer Carl
Published: February 2008

1. In this Journal for September 1913 and March 1915, preliminary accounts were published by me of some results of the aurora borealis expedition to Bossekop, which I undertook in the spring of 1913. The present communication concerns the very extensive material of the nights, March 14, 15, and 15, 16, 1913, comprising about 100 auroral photograms.

The main conclusions of the second report are confirmed, especially in regard to the lower limit of the altitude of the aurora, as will be seen in Fig. 1, representing graphically the height above the Earth's surface of all the points of the aurora, which have been calculated.