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Showing papers in "Journal of Geophysical Research in 1900"


Journal ArticleDOI
TL;DR: In this paper, it is shown how the glass window in the front end of the box has been removed entirely, and there is used instead a cloth hood, fastened to the box and fitting snugly by means of a ring over the observing telescope.
Abstract: The source of error complained of by Dr. Morize has been eliminated in the present form of magnetometer used by the Coast and Geodetic Survey. The above cut will show how this has been done, viz., the glass window in the front end of the box has been removed entirely, and there is used instead a cloth hood, fastened to the box and fitting snugly by means of a ring over the observing telescope. The window in the back end of the box can be turned aside, on a pin, when observing on the mark. It may also be pointed out that the azimuth mirror, which constitutes the weak part of the Kew magnetometer, is replaced in this form of instrument by a special theodolite attachment (as shown on the right of the cut) fitting on the same base as the magnetometer, the alt-azimuth method for determining the meridian being used. By this method the observer is independent of the longitude of the place, and the need of great accuracy in the times of observation.

15 citations


Journal ArticleDOI
TL;DR: In this paper, it has been arranged that on certain days throughout the year special simultaneous magnetic observations be made by the various parties in the in the employ of the Coast and Geodetic Survey.
Abstract: In order to ascertain over how large an area the variations as recorded at the magnetic observatories may apply, it has been arranged that on certain days throughout the year special simultaneous magnetic observations be made by the various parties in the in the employ of the Coast and Geodetic Survey. This is a question of fundamental importance in conducting the magnetic survey of the United States and countries under its jurisdiction; namely, in the reduction of the field determinations of the magnetic elements to the common epoch of the survey, great dependence will have to be put upon the continuous records of the magnetic variations as obtained at the magnetic observatories.

13 citations


Journal ArticleDOI
TL;DR: A possible cause of the Earth's magnetism is the rotation of an electrostatic field within the Earth, as Rowland's experiments have proved (Phil. Mag. as discussed by the authors ).
Abstract: A possible cause of the Earth's magnetism is the rotation of an electrostatic field within the Earth, as Rowland's experiments have proved (Phil. Mag. [5] xxvii) that a moving charge of electricity produces a magnetic field analogous to that of a current. If the Earth carries round an electrostatic field in its rotation, then it will have the axis of its magnetic field identical with the axis of rotation which is the chief approximate fact of the Earth's magnetism. The actual obliquity of the magnetic to the rotational axis is traced to unsymmetrical magnetic permeability of the Earth, which also causes the induction of Earth currents, the secular variation of whose tracks is the cause of magnetic secular variation. The theory advanced to account for daily variation is that under the action of the Sun's rays the oxygen and ozone of the atmosphere become the active substance of a large secondary battery or accumulator whose alternate charge and discharge are the cause of the daily variations.

10 citations


Journal ArticleDOI
TL;DR: In the March (1899) issue of the JOURNAL, L. A. Bauer published a paper entitled, "The Physical Decomposition of the Earth's Permanent Magnetic Field,” and in that paper were developed the principles and formulae upon which the decomposition was based as discussed by the authors.
Abstract: In the March (1899) issue of the JOURNAL, L. A. Bauer published a paper entitled, “The Physical Decomposition of the Earth's Permanent Magnetic Field,” and in that paper were developed the principles and formulae upon which the decomposition was based. The present paper is an application of these principles and formulae for a special portion of the Earth, namely, the United States of America. This investigation is based upon the series of magnetic charts constructed by Mr. C. A. Schott for the year 1900, and published in Appendix No. 1, Coast and Geodetic Survey Reports for 1896, and 1897. These charts give us the best possible representation of the distribution of the magnetic elements in the United States up to the date of the construction of the charts.

9 citations


Journal ArticleDOI
TL;DR: In this paper, the authors discuss the effect of paralleisme of verres de la boite magnetique on terrestrial magnetism, a phenomenon that was identified by Charles Chree, le savant directcur de l'Observatoire de Kew.
Abstract: La cause d'erreur causee par le defaut de paralleisme des verres de la boite, existant dans l'emploi du magnetometre du modele de Kew (eten general dans tousles instruments avec lesquels le pointe sur le barreau aimante est effectue differemment de celui sur la mire) a ete signalee a l'attention des lecteurs du “Terrestrial Magnetism” par l'extrait d'une de roes lettres que M. Littlehales a en l'obligeance de transcrire dans la livraison de Mars dernier. Cette publication m'a valu, de la part de Mr. Charles Chree, le savant directcur de l'Observatoire de Kew, une lettre par laquelle il me suggere une facon simple de verifier lequel des deux verres qui ferment la boite magnetique, devie par son prismatisme le rayon qui le traverse.

4 citations


Journal ArticleDOI
TL;DR: In the field of terrestrial magnetism, especially, did further development of Gauss's method take place but recently, hardly more than a decade ago as mentioned in this paper, and this activity has disclosed a great number of new ideas and points of view, and revealed a more intimate connection between terrestrial magnetisms, meteorology, and atmospheric electricity than was at first suspected.
Abstract: It is characteristic of Gauss's method of working that he published no investigation until it was either finally completed or had been developed to the highest stage attainable at the time with the material at hand. Were there any weak points, no opportunity to point these out was neglected by him. Herein lies the classic value of his works, and so, naturally, it came to pass that for many years the principal endeavor of his successors was to fill in the missing links, and that only recently attempts have been made to farther develop his methods. In the field of terrestrial magnetism, especially, did further development of method take place but recently—hardly more than a decade ago. Since then, however, a wonderful zeal, enthusiasm, and singleness of purpose, as probably in no other branch of geophysics, have been displayed. This activity has disclosed a great number of new ideas and points of view, and has revealed a more intimate connection between terrestrial magnetism, meteorology, and atmospheric electricity than was at first suspected. This discovery, though but very recent, is leading future investigation into totally different paths from those of the earlier days.

2 citations


Journal ArticleDOI
TL;DR: In this paper, it was found that the large variations in atmospheric electricity concomitant with the prevailing meteorological conditions of the atmosphere, in consequence of which it has been necessary to separate the phenomena observed in clear, normal weather entirely from, those obtained during disturbed weather conditions, such as cloudiness, rain, snow, etc.
Abstract: Complaints can be made with justice at present that, although in every year new theories of atmospheric electricity are brought forth, the amount of useful observational data, however, increases very slowly. This is largely due to the difficulty experienced in measurements in atmospheric electricity, a difficulty greatly increased by the numerous disturbing influences encountered because of the impurities of the air in cities and in their vicinity. A further difficulty is due to the large variations in atmospheric electricity concomitant with the prevailing meteorological conditions of the atmosphere, in consequence of which it has been found necessary to separate the phenomena observed in clear, normal weather entirely from, those obtained during disturbed weather conditions, such as cloudiness, rain, snow, etc. The latter phenomena are to be regarded as disturbances of the usual normal electric field which prevails during fine weather.

2 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the magnetic after-disturbance effect and found that after a magnetic storm the horizontal force is generally less than it was before, and that the vertical component mostly decreased, though not with the same regularity.
Abstract: The recent article, by Dr. Adolf Schmidt, in the Meteorologische Zeitschrift, 1889, p. 385» entitled, “Uber die Ursache der Magnetishen Sturme,” induces me to return to my paper, published in the same journal (1895, p. 321), “Die Erdmagnetische Nachstorung,”. The phenomena of disturbance described in my paper, examined anew by the light of Dr. Schmidt's considerations on moving current-vortices, furnish, in my opinion, new indications for an explanation of the nature of magnetic disturbances. For this purpose I propose to recapitulate briefly the chief results of the investigations concerning the phenomenon described by me, which I term the magnetic “postturbation,” or the magnetic after-disturbance effect. The daily means of the magnetic elements observed at the different observatories formed the principal basis for these inquiries. A superficial look at those quantities—e. g., for Pawlowsk—shows that immediately after a magnetic storm the horizontal force is generally less than it was before, and that it increases during the following days. A synoptical tabulation of a number of such series of diurnal means confirmed this result; it showed, in the majority of cases, that the horizontal force increases regularly after any magnetic storm, and that the westerly declination decreases. The vertical component mostly decreased, though not with the same regularity.

2 citations


Journal ArticleDOI
TL;DR: Toepfer and Toepfer as discussed by the authors built a light system of magnetometers for the measurement of the variations of the Earth's magnetic force, taking advantage of a comparison with a compensating force; e.g., the magnetism of a bar and the directive force of the bifilar suspension.
Abstract: For the measurement of the variations of the Earth's magnetic force, advantage is taken of a comparison with a compensating force; e.g., the magnetism of a bar and the directive force of the bifilar suspension. Both forces mentioned are not free from changes in the course of time, and are greatly affected by temperature. The force of torsion of a unifilar suspension has only been applied with advantage since the invention of quartz fibers. The systems of magnets and suspensions, which weigh at least 20–30 grams usually employed with magnetometers are not suited for quartz fiber suspensions, as too strong fibers must be used. Magnetometers have, therefore, been built at my request by the firm of O. Toepfer, of Potsdam, which are provided with a light system of magnets (weighing about 1.5 g.), and possess several advantages over the instruments used hitherto. Among these are to be mentioned : easy accessibility to the system of magnets, clamping of the lower suspension, so that slight displacements of the mirrors can be made; moreover, a damping adjustable at pleasure; finally, a fixed mirror for photographic registration, which can be displaced with ease and certainty. The system of magnets carries two mirrors, inclined at a certain angle to each other, so that the range of registration is increased twofold. The magnet consists of a well-hardened laminar piece of watch-spring steel, 25 mm. long, which can be turned at pleasure about the axis of the system. The frame, supporting mirrors and magnet, is made of aluminum, and is hung, by means of a double hook, on a small cross piece attached to the bottom of the fiber suspension.

1 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the best way of erecting an observatory for terrestrial magnetism and the mode of answering this question depends on the purpose aimed at in building the observatory.
Abstract: At the time of the removal of the Central Observatory of the Royal Meteorological Institute of the Netherlands from Utrecht to a place which would better answer the purposes of such a building, there arose the question as to the best way of erecting an observatory for terrestrial magnetism. The mode of answering this question depends wholly on the purpose aimed at in building the observatory. It is my intention to indicate, in a few words, my opinion on the subject, and the way in which it has been realized at de Bilt, near Utrecht. During the past ten years the science of terrestrial magnetism has received a great impetus. Everywhere magnetic surveys have been instituted and finished, or are still in progress. The theoretical requirements are getting more and more exacting, and are demanding, in consequence, greater refinement in the instruments employed and in the methods of observation.

1 citations



Journal ArticleDOI
TL;DR: In den Vereinigten Staaten und Alaska, the Coast and Geodetic Survey (CoGS) as discussed by the authors has been ausgefuhrt in 60 years.
Abstract: Seit 60 Jahren sind von der Amerikanischen Kusten- und Geodatischen Vermessung—die sogenannte “Coast and Geodetic Survey”—vereinzelte magnetische Arbeiten in verschiedenen Theikn Nord-Amerikas, hauptsachlich in den Vereinigten Staaten und Alaska, ausgefuhrt worden. Wegen der beschrankten Geldund Hulfsmittel war es leider fur ein so grosses Land wie die Vereinigten Staaten unmoglich, diese Arbeiten in solch einer detaillirten Weise, wie das in mehreren Staaten Europas geschieht, zur Ausfuhrung zu bringen. Doch ist mit den beschrankten Mitteln Vieles von grossem Werth fur die erdmagnetische Forschung beigetragen worden—besonders auf dem Gebiete der Sacular-Variation. In keinem anderen Lande ist dieser rathselhaften Erscheinung des Erdmagnetismus so viel Aufmerksamkeit geschenkt worden.

Journal ArticleDOI
TL;DR: In der oben genannten Mittheilung findet Herr Moureaux bezuglich des taglichen Ganges der magnetischen Storungen, dass bei der Declination ein Maximum um etwa 1h a.m.; ein Minimum in den Morgenstunden von 5-8 Uhr erreicht wird as discussed by the authors.
Abstract: In der oben genannten Mittheilung findet Herr Moureaux bezuglich des taglichen Ganges der magnetischen Storungen, dass bei der Declination ein Maximum um etwa 1h a. m.; ein Minimum in den Morgenstunden von 5–8 Uhr erreicht wird. Bei den Storungen der Horizontal-Intensitat ist der tagliche Gang ein ganz anderer, hier fallt das Maximum auf die Mittagstunden, das Minimum auf ungefahr 5h a. m. Diese Resultate stehen nun mit fruheren, von anderen Forschern gefundenen nicht ganz im Einklang.