bluuebunny/crossref_metadata_2025 huggingface dataset:
Jurassic and Triassic paleomagnetism of South Korea
Authors: Kim Kwang Ho , Van der Voo Rob
Published: February 2008

Middle to Late Jurassic samples have been collected from granitic rocks in three geological subdivisions of South Korea, from north to south: Kyonggi Massif, Okchon Folded Belt and Ryongnam Massif. Triassic samples (granites and sediments) were collected in the Ryongnam Massif and its border area with the Okchon Folded Belt. The Jurassic declinations of the two massifs are northeasterly (mean D/I = 39.6°/+57.6°, N = 7 sites, k = 31, α95 = 11.1°), whereas the intervening Okchon Folded Belt reveals northwesterly Jurassic declinations (D/I = 337.5°/+47°, N = 7 sites, k = 32, α95 = 10.8°). Reversed‐polarity directions are rare, but have been observed in three localities. The widespread occurrence of similar directions in a given province argues against major tectonic tilting of the granites; two sites in Jurassic sediments provide additional structural control. We interpret the direction difference between the Okchon belt and the adjacent massifs as due to left‐lateral shear in an actively deforming continental margin during the Late Jurassic‐Early Cretaceous Daebo Orogeny. The Triassic directions from the Ryongnam Massif and its border area are east–northeasterly (D/I = 62.9°/+35.7°, N = 5, k = 27, α95 = 15°) with the sediments showing normal and reversed polarities. Comparisons with Jurassic and Triassic paleomagnetic results from adjacent blocks in Asia (Eurasia, North Korea, North and South China) are hampered by a paucity of reliable paleopoles. What seems clear, however, is that North and South China and the major part of Korea yield Jurassic and younger paleopoles that are to first approximation similar; the exception is formed by the results from the Okchon Folded Belt. The aggregate of the China and Korea Blocks yields mean paleopoles for this interval that are different from those published for Eurasia, but this may be due to imperfections in the Eurasian reference poles. For the Triassic, the directions and paleopoles of the China Blocks and the Ryongnam Massif of South Korea are dissimilar, resulting in interpretations of the area in terms of relative motions (mainly rotations).
Right‐lateral shear along the Northwest Pacific Margin and the India‐Eurasia Collision
Authors: Jolivet Laurent , Davy Philippe , Cobbold Peter
Published: February 2008

Right‐lateral shear along the eastern margin of Asia, from the Eocene to the Present has led to the opening of pull‐apart basins, intracontinental such as the Bohai basin, or oceanic such as the Japan Sea. We suggest in this paper that this right‐lateral shear is a consequence of indentation of Asia by India. As in small‐scale analog experiments, we conclude that antithetic wrench faults accommodate the counterclockwise rotation of large domino blocks between two major left‐lateral shear zones (Tien Shan‐Baikal‐Stanovoy for the northern one, and Qin Ling for the southern one). We discuss the compatibility of this mechanism, which involves a rather small amount of extrusion, with the fast eastward expulsion described for southeast Asia. We re‐emphasize the role played in the opening of marginal basins by the Pacific subduction as a free boundary to the east.
Regional aeromagnetic anomalies in Ellsworth Land: Crustal structure and Mesozoic microplate boundaries within West Antarctica
Authors: Maslanyj M. P. , Storey B. C.
Published: February 2008

The structural relationship between West Antarctic crustal blocks has remained uncertain due to a lack of information concerning sub‐ice crustal structure. A regional aeromagnetic reconnaissance of Ellsworth Land between 72 and 80°S and 65 and 100°W, completed as part of an integrated geophysical and geological investigation, provides the opportunity to study the ice‐covered area where several continental crustal blocks meet: Antarctic Peninsula, Thurston Island, Ellsworth‐Whitmore mountains and Haag Nunataks. The anomaly map is dominated by two major positive magnetic areas. Firstly, the Pacific Margin Anomaly (PMA) continues as a coastline‐parallel feature 100 km wide through Antarctic Peninsula and Thurston Island. The broad curvilinear anomaly with magnetic maxima of 200–600 nT is related to a mafic batholith and related intrusions and structures of the Pacific margin, mostly of Mesozoic age. Second, a zone of high intensity anomalies (200–1000 nT) of variable wavelengths (20–150 km) define an extensive area of highly magnetic Precambrian basement which is exposed at Haag Nunataks but is for the most part buried beneath ice and non‐magnetic cover. The geophysical data suggest that some of the crustal blocks have common structural features, their boundaries are more complex than originally thought and aeromagnetic provinces do not entirely correspond to the topographically defined boundaries of the crustal blocks. The Antarctic Peninsula and Thurston Island blocks are thought to have remained juxtaposed since the emplacement of the intrusive body related to the PMA. The Haag Nunataks Precambrian basement probably extends beneath the south and west margins of the Weddell Sea embayment and beneath the Ellsworth Mountains. The origin of long wavelength lineations beneath the Weddell Sea embayment is speculative. If they are related to Haag Nunataks Precambrian basement then the data offer insight into the trend of the Palaeozoic Ellsworth Mountain fold belt and support rotation models. Alternatively, if the anomalies are imaging break‐up related rifting trends, the lineations may provide extension and movement directions.
Evidence for a fossil transform fault in the Solund‐Stavfjord Ophiolite Complex: West Norwegian Caledonides
Authors: Skjerlie K. P. , Furnes H.
Published: February 2008

On the island of Tviberg, West Norway, a sheeted dike complex is rotated anticlockwise into parallelism with a zone of strong deformation hosting screens of sheared meta‐ultramafite. Incompatible element‐enriched high‐level plutonic rocks and two swarms of mafic dikes are intruded into sheared and unsheared meta‐ultramafites. Intrusion and sinistral shearing of the high‐level plutonic rocks and an old swarm of mafic dikes took place contemporaneously with sinistral shearing of the meta‐ultrabasites. These field relationships are interpreted to reflect magmatism within a transform fault, and the dike rotation is explained as fault drag along a strike‐slip zone in the transform. A younger swarm of mafic dikes, striking at a high angle to the shear zones, transects all tectonic structures and may reflect a second phase of magmatism within the transform. In fault contact with the transform fault related plutonic rocks and dikes, lenses of serpentine diatreme breccias and lenses of sediments composed of mafic and ultramafic detritus are hosted in a phyllonitic matrix comprising basic, ultrabasic and continent‐derived detritus. This rock unit is interpreted as an ophiolitic mélange, and it probably started to form when obduction of the ophiolite nucleated on the transform.
Is the principal source of the secular variation of the Earth's magnetism within or without the Earth's crust?
Authors: Bauer L. A.
Published: February 2008

In the papers on the “Distribution and the Secular Variation of the Earth's Magnetism,” presented before the Washington Philosophical Society in May, 1895, I showed that certain laws pertaining to the distribution of the magnetic elements over the earth's surface are similar to those pertaining to the secular variation as derived thus far. I shall refer to four of the deductions then made, as they will be found interesting in connection with some of the conclusions reached in this paper. These laws2 are:

I. The minimum range in declination along a parallel of latitude occurs near the equator, generally increasing upon leaving the equator. II. The maximum range in inclination along a parallel of latitude occurs near the equator, generally diminishing upon leaving the equator. III. The minimum average secular change in declination along a parallel of latitude from 1780 to 1885 occurred near the equator, the values generally increasing upon leaving the equator. IV. The maximum average secular change in inclination along a parallel of latitude from 1780 to 1885 occurred near the equator, the values generally diminishing upon leaving the equator.
Note sur une cause d'erreur dans la détermination de la déclinaison magnétique
Authors: Morize Par H.
Published: February 2008

La cause d'erreur causée par le défaut de paralléisme des verres de la bôite, existant dans l'emploi du magnétomètre du modèle de Kew (eten général dans tousles instruments avec lesquels le pointé sur le barreau aimanté est effectué différemment de celui sur la mire) a été signalée à 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 suggère une façon simple de vérifier lequel des deux verres qui ferment la boîte magnétique, dévie par son prismatisme le rayon qui le traverse.
Report on the observations of magnetic declination made at Sawah Loento, Sumatra, during total eclipse of May 17–18, 1901, by the party of the Massachusetts Institute of Technology, Boston
Authors: Hosmer G. L.
Published: February 2008

In selecting the station for the declination observations during the eclipse, unusual care was taken to avoid possible magnetic disturbances. The magnetometer was at first placed at a point about 350 feet from the camera and transit buildings, and series of readings were made to see if the needle was affected by the distant railroad trains. No effect was noticed in three days' observations. Nevertheless, it was thought that such disturbances might be possible, and also that the iron in the buildings might introduce a disturbance, so it was decided to move the magnetometer to the summit of a hill about 3,000 feet northeastward of former position and consequently farther from the railroad.
Magnetic observations in Southeast China
Authors: de Moidrey J.
Published: February 2008

The following magnetic observations are extracted from the “Atlas du Haut Yang‐tse‐kiang,” by the Rev. F. S. Chevalier, late Director of the Zi‐ka‐wei Observatory. The declination and the horizontal intensity were determined with a magnetometer of the Kew pattern, by Elliott, No. 49, and the azimuth of the mark observed with a theodolite by Brunner. The dip circle used is a Dover make.

The observations were made from May, 1897, to April, 1898, and reduced to January 1, 1898, by comparison with the Zi‐ka‐wei Observatory. To be sure, several of the stations were somewhat too far from the observatory for this purpose, but no other course was possible, Some of the results—for instance, those for Han‐kau—are the means of several observations taken at different times, and which were found to agree well. At other places—e. g., Wu‐hu—observations were also taken several times, but they happened not to agree and have therefore been omitted. The cause was afterwards ascertained to have been the proximity of a heap of old tin boxes. The declination in Chin‐kiang is much greater than could have been expected, but there is no reason to doubt the observations, which agree very well.
Messungen des electrischen Potentialgefälles auf Spitzbergen und Juist
Authors: Elster Julius
Published: February 2008

Im Sommer des Jahres 1900 bot sich mir Gelegenheit, in dem nördlichsten Teile von West‐Spitzbergen einige luftelectrische Messungen vorzunehmen. Am 5ten August, abends, ging unser Dampfer in dem unter dem 79° N. Br. gelegenen Virgohafen vor Anker. Das Wetter am folgenden Tage war schön, der Himmel bis auf vereinzelte Cirri wolkenlos ; an der Küste herrschte Windstille, in den freier gelegenen Teilen des Hafens frischte gegen Abend der Wind etwas auf. Als Standort für die Exner' sehen luftelectrischen Apparate wählte ich an Land eine frei gelegene Stelle unweit der Trümmer der Andre'schen Ballonhalle.
Paul Passalskij und sein letztes erdmagnetisches Werk
Authors: Leyst E.
Published: February 2008

Die erdmagnetische Wissenschaft verlor am 12/25. November 1900 durch einen plötzlichen Tod einen ihrer würdigsten Vertreter in Russland—Paul Passalskij. Ein reich begabter und äusserst thätiger Gelehrter ist nach kaum fünfjähriger, aber immense frucht: barer Thätigkeit in ihm zu Grabe getragen worden, im Alter von nur 29 Jahren. Sein äusserer Lebensgang ist daher in nur wenigen Worten zu schildern.
Note sur la variation séculaire de la déclinaison à Zi‐Ka‐Wei (Chine)
Authors: de Moidrey J.
Published: February 2008

La variation séculaire de la déclinaison magnétique à Zi‐ka‐wei présente, in 1878, 1888 et 1898, trois minimums accentués, sùr lesquels nous avions attiré l'attention dans la préface du Bulletin de l'Observatoire pour 1898 (p. iii).

M. Mascart écrivait en 1900: “Il semble que la période des taches solaires se traduit dans les valeurs successives de la variation séculaire.” (Traité du magnétisme terrestre, p, 284). Et il citait les observations de M. Moureaux au Parc St. Maur où la déclinaison, qui est occidentale comme ici, diminue plus rapidement les années où les taches sont importantes.
Atmospheric electricity and terrestrial magnetism at the British Association for the Advancement of Science 1903
Authors: Rotch A. Lawrence
Published: February 2008

These topics were more than usually prominent at Southport, on account of the joint meeting of the International Meteorological Committee under the presidency of Professor Mascart, by reason of the interest aroused by Sir Norman Lockyer's paper before the Physical Section of the Association and from the fact that the presidential address to the Geographical Section was delivered by a magnetician.

There were present a majority of the International Meteorological Committee, besides several members of two subcommittees, including the writer. The proceedings, so far as they related to the above subjects, were as follows: The Royal Saxon Academy of Sciences submitted the text of resolutions adopted by the Commission on the Physics of the Globe, regarding the scientific organization of investigations in atmospheric electricity, and it was decided that if these resolutions were approved by the International Association of Academies, the Committee would aid in having the investigations undertaken. Dr. Paulsen, of Copenhagen, exhibited an instrument for collecting atmospheric electricity by radio‐active salts. It was voted that Dr. Snellen, who had resigned the directorship of the Royal Dutch Meteorological Institute to take charge of the magnetic observatory at De Bilt, near Utrecht, be authorized to receive and distribute the observations on quiet magnetic days. The question proposed by Rev. J. de Moidrey concerning disturbed days was referred to the magnetic subcommittee. It was announced that Professor Rücker had consented to remain chairman of this committee, which would hold a meeting in conjunction with the British Association at Cambridge in August, 1904.
Early history of the mariner's compass and earliest knowledge of the magnetic declination according to Bertelli
Authors: Hazard D. L.
Published: February 2008

As early as 1866 P. Timoteo Bertelli began the study of the origin and early history of the mariner's compass. The results of his investigations were published in detail in 1893 in a paper entitled “Studi storici intorno alia bussola nautica.” His conclusions met the approval of most scientific men; but there were some prominent men in Italy who took exception to his views as to the compass being of Chinese origin and who maintained that the compass was invented as well as perfected at Amalfi, Italy. Bertelli's later contributions to the subject, in reply to these opponents, present the results of his more recent investigations, and treat some phases of the subject in greater detail than was the case in the earlier publications.
Magnetic survey of the Dutch East Indies
Authors: van Bemelen W.
Published: February 2008

It is obvious that the degree of detail of a magnetic survey, as determined by dividing the total area by the number of stations, should be in accordance with the general aims of the survey.

If the observer intends to investigate the relations between geological structure and distribution of the magnetic force, a dense network of stations is required. On the other hand, if he aims at a contribution to the knowledge of the general course of the iso‐magnetic curves over the globe, necessary for the derivations of characteristic functions, as for instance the potential function, a much smaller number of stations will suffice.
Note sur l'amplitude de l'oscillation diurne de la déclinaison magnétique et son inégalité annuelle
Authors: de Moidrey J.
Published: February 2008

Les moyennes mensuelles de l'amplitude de l'oscillation diurne fournissent une courbe d'une assez grande régularité, dont le maximum se présente en été et le minimum en hiver, dans notre hémisphère. Le contraire a lieu dans l'hémisphère sud.

On se borne en général à ce caractère principal de la variation annuelle. C'est celui par exemple qu'a envisagé M. Nordmann dans son essai récent, et fort séduisant, d'interprétation du magnétisme terrestre par les ondes hertziennes.
Principal magnetic disturbances recorded at Cheltenham Magnetic Observatory, Sept. 1–Nov. 30, 1904
Authors: Wallis W. F.
Published: February 2008

II. Began suddenly on September 24th, at 14h 44m, 75th meridian mean time, and ended on September 20th, at about 5h. The maximum and minimum ordinates are as follows:

1The times given, according to the information courteously supplied by the Superintendent .of the Sydney office, Mr. Young, applies to the 150th meridian, and is hence 10 hours ahead of Greenwich.
Some observations of the diurnal variation of the magnetic declination at Cuajimalpa near the city of Mexico
Authors: y Anda Manuel Moreno
Published: February 2008

The following observations were made on September 15, October 1 and 15, November 1 and 15, and December 1 and 15, 1902, at Cuajimalpa, situated about 11 miles southwest of the City of Mexico. The approximate geographical position of the station is: latitude, 19° 20′N., and longitude, 99° 13′ or 6h 37m, west of Greenwich.

The observations on the first four days mentioned were obtained with an Elliott magnetometer, whereas in those on the last three days a Mascart declinometer was used, referring the readings to the Elliott magnetometer. The mean results are contained in the following table. The mean of all the hourly readings gives the value D = 7° 27′.56 East. By subtracting this mean from the hourly values, the figures for the diurnal variation in the last column were derived, the sign + meaning hence an excursion of the needle to the east of the mean position.
Principal magnetic disturbances recorded at Cheltenham Magnetic Observatory, Dec. 1, 1904, to Mar. 1, 1905
Authors: Wallis Wm. F.
Published: February 2008

16. A moderate disturbance began on December 14th, at about 10h, and ended on December 16th, at about 15h. The maximum and minimum ordinates are as follows:
Earthquake disturbances recorded on the magnetographs at the observatories of the United States Coast and Geodetic Survey: No. 1
Authors: Burbank J. E.
Published: February 2008

One of the earliest records of a disturbance of the Earth's magnetic elements by an earthquake seems to be that of Father Eschinardi, at Rome, in 1681.2

At the time of the Lisbon earthquake in 1855, Sarti is said to have observed a similar disturbance. On November 4, 1799, at Cuniana, in South America, Humboldt3 observed that while the declination and horizontal intensity were apparently unchanged by an earthquake, the dip was diminished 48′ from which value it slowly recovered. In October, 1802, Humboldt3 at Lima observed that a needle made 219 swings in ten minutes before an earthquake and only 213 swings in ten minutes after, indicating a decrease of about 5 per cent in horizontal intensity. The dip before the earthquake was 9°35′.4, after the earthquake g°07′.2. Similar results have not been obtained by magnetic surveys in Japan.
Inauguration of the magnetic survey of the North Pacific Ocean
Authors: Bauer L. A.
Published: February 2008

As announced in the previous issue, p. 103, the brig “Galilee” of San Francisco, a wooden sailing vessel built in 1891, of length 132.5 feet, breadth 33.5 feet, depth 12.7 feet, displacement about 600 tons, has been chartered by the Department Terrestrial Magnetism of the Carnegie Institution of Washington for the purpose of making a magnetic survey of the North Pacific Ocean. After the various necessary alterations, e.g. substitution of the steel rigging by hemp rigging, etc., etc., were made, the vessel entered upon her duties early in August. Magnetic observations were made at various places on the shores around San Francisco Bay and the most suitable place for “swinging ship” by their aid determined. The ship was “swung” with the aid of a tug on August 2d, 3d, and 4th in San Francisco Bay between Goat Island and Berkeley, California, and the various deviation co‐efficients were determined.
Magnetograph records of earthquakes with special reference to the San Francisco earthquake, April 18, 1906
Authors: Bauer L. A.
Published: February 2008

The San Francisco earthquake was one of several large earthquakes recorded the world over since the beginning of this year. The writer's prime interest in it as a magnetician is in the record it left behind on the magnetographs at various magnetic observatories of the United States Coast and Geodetic Survey.

It has happened several times within the last few years that earthquakes have occurred in this country which were not recorded for one reason or another, on the existing seismographs, but were indicated by the record of certain magnetographs. The most notable instance was the New England earthquake of March 21, 1904, at about eight minutes after one o'clock in the morning, Eastern time. Seismographs of the Milne type at Toronto, Canada, and Baltimore, Maryland, and of the Bosch‐Omori type at the Weather Bureau, Washington, D.C., failed to give any record of this earthquake, which was appreciably felt throughout the New England States. The magnetograph at the observatory, Cheltenham, Maryland, sixteen miles southeast of Washington, gave a distinct record at 1h 05m to 1h 17m eastern time. So there have been a number of earthquakes recorded by the magnetograph at Baldwin, Kansas, which were felt in the Middle States and reported in the papers. In fact, at this observatory, situated in a region where felt and unfelt local and regional earthquakes are comparatively frequent—note for example the many recent occurrences—more records of earthquakes are obtained on the magnetograph than at any of the other magnetic observatories.
Aggiunta alla nota “Sopra le perturbazioni magnetiche dovute al terremoto della Calabria dell'8 Settembre 1905”
Authors: Rizzo G. B.
Published: February 2008

Nella Nota sopra citata, sulla fede di una comunicazione ricevuta dal Signor Direttore della Sezione Geofisica dell' I. R. Ufficio Idrografico di Pola, ho scritto che ivi, fra le ore 1 e 2 (t. m. civ. Gr.) del giorno 8 settembre 1905, le curve magnetiche non presentarono traccia di perturbazione. Ed ho anche cercato di spiegare questa cosa singolare, che, ad una così piccola distanza dal l'epicentre del movimento sismico, non vi fosse stata una corrispondente perturbazione degli strumenti magnetici.

Ora, con una cortese lettera, della quale lo ringrazio, il Signor Direttore dell' I. R. Ufficio Idrografico di Pola mi informa come in occasione del terremoto della Calabria, che è oggetto del mio studio, fu invece registrata una cospicua pertubazione nella curva del declinometro che prima non era stata osservato a circa 1h 46m, cioè in corrispondenza alla fase principale del movimento sismico registrato dal sismografo “Vicentini.”
Distribution of electricity in the atmosphere
Authors: Homma Y.
Published: February 2008

INTRODUCTION.

The distribution of electricity in the atmosphere has hitherto been calculated, so far as the author is aware, solely on the assumption that the portion of the Earth's surface considered is a plane, the equipotential surfaces in the atmosphere being planes parallel to it.2 This procedure, simple as it is, admits of only limited application of the results to the actual problems. In the following the calculation is based upon an assumption, which, while still decidedly too simple to cover all the details occurring in the exceedingly complicated field of atmospheric electricity, may be taken as sufficient for the standard case, before we are provided with more improved observational data from all quarters of the world.
Scientific results of the Ziegler polar expedition of 1903 to 1905
Authors: Fleming J. A.
Published: February 2008

The scope of the scientific work of the Ziegler Polar Expedition during the years 1903 to 1905, may be summarized by the following section headings of the results reported in the volume1 recently issued:

A—Magnetic Observations and Reductions;

B—Notes and sketches of the Auroræ Borealis ;

C—Meteorological Observations and Compilations;

D—Tidal Observations and Reductions ;

E—Astronomic Observations and Reductions, and

F—Map Construction and Survey Work.
The life and work of Maurits Snellen (1840–1907)
Authors: van Everdingen E.
Published: February 2008

MAURITS SNELLEN was born on April 1, 1840, in the village of Zeist, not far from Utrecht. After visiting the gymnasium at Gouda, he entered the University of Leiden and devoted himself to the study of mathematics and physics. As a result of this study, he obtained the degree of doctor of mathematics and physics in 1865. From 1863 to 1864 he was a teacher of physics and mechanics at Leiden, then from 1864 to '67, teacher of physics in the gymnasium at Groningen, and lastly from '67 to '73 teacher of mathematics at Delft.
Is the Earth's action on a magnet only a couple?
Authors: Bauer L. A.
Published: February 2008

If the action of the Earth on a magnetic needle does not consist solely in a couple, then, contrary to our usual ideas, the needle would be subject, not only to a motion of rotation, but also to one of translation. Accordingly a compass needle might be caused to press against the supporting pivot or a dip needle exert an additional pressure on the surfaces on which the pivots rest. In order to have only a couple acting on the magnet it is necessary that the following three conditions be fulfilled exactly:

a. That the forces acting on the two ends or “equivalent poles” of a magnet be opposite.

b. That they be equal.

c. That they be parallel.
Recent determination of the solar constant of radiation
Authors: Abbott C. G. , Fowle F. E.
Published: February 2008

The present volume1 is an account of the work of the Astrophysical Observatory of the Smithsonian Institution from 1900 to 1907, with details of the investigations made, the apparatus and methods used, and the results obtained.

Speaking broadly, the investigation relates to the intensity of the rays of the sun and the dependence of the Earth's temperature thereon. The subject is treated in three parts: First, the amount of the solar radiation as it would be found if measured outside the Earth's atmosphere, at mean solar distance, or, as is often termed, “the solar constant of radiation;” second, the dependence of the Earth's temperature on the amount of solar radiation; third, the difference in brightness between the center and edge of the sun's disk and its relation to the quantity of solar radiation received by the Earth.
Report on the atmospheric electricity observations made on the magnetic survey yacht “Galilee,” 1907–08
Authors: Dike P. H.
Published: February 2008

In addition to the magnetic work on board the “Galilee,” an attempt was made during her final cruise (Sitka, Honolulu, Marshall Islands, Christchurch, Callao, and San Francisco), 1907–08, to secure some observations at sea of the electrical condition of the atmosphere. These were intended to include potential gradient, conductivity, and the radioactive deposit on a charged wire.

The first, the determination of the potential gradient, after careful consideration of the conditions on board a sailing vessel, seemed quite impracticable, and no serious attempt was made to secure observations. The rolling of the ship, the flapping of the sails, and the varying positions of the yards and boom under various sailing conditions, all contributed to make the problem of reducing observations of potential gradient to a uniform basis too complicated to be undertaken. On board a steamer the conditions would be less variable and it might be possible to reduce readings to values for undisturbed sea by means of simultaneous observations in port with the vessel at anchor and the second collector and electroscope mounted on a raft at some distance from the vessel.
Sur le mouvement d'une aiguille aimantée librement suspendue
Authors: de Moidrey J.
Published: February 2008

Si on suppose une aiguille magnétique librement suspendue, et qu'on imagine un observateur placé au point de suspension et regardant le pôle nord, le Dr. L. A. Bauer a montré qu'en la plupart des stations le mouvement se produit dans le sens des aiguilles d'une montre. M. G. W. Littlehales a appliqué, ici même (vol. I, p. 62), ce théorème à Zi‐ka‐wei et à Hong‐kong, et proposé des formules empiriques pour représenter la variation séculaire de D et de I.

J'ai été conduit a revenir sur ce sujet et à ajouter une quinzane d'années aux listes dont disposait M. Littlehales. J'y ai joint Manille.
Magnetic observations in northeast Africa
Authors: Dehalu M.
Published: February 2008

You have heard, without doubt, that, according to the wish expressed by the Congress of Academies meeting at Vienna, July, 1907, England and Belgium decided to measure the arc along the 30th meridian in the vicinity of the equator forming the central frontier of Uganda and Belgian Congo.

I had the honor to be appointed a Belgian delegate to this geodetic mission, and I wished to take advantage of my sojourn in Africa to make there a good series of magnetic observations.
Discontinuance of the Baldwin Magnetic Observatory and establishment of the Tucson Magnetic Observatory
Authors: Faris R. L.
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.
Comparisons of magnetic observatory standards by the Carnegie Institution of Washington No. I
Authors: Fleming J. A.
Published: February 2008

The project of a general magnetic survey of the globe, undertaken by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, and co‐operating organizations, makes necessary the determination of possible instrumental differences existing between the standards used in different countries. The pioneer work of van Rijckevorsel, Solander, Rücker and Thorpe, Moureaux, Palazzo, Bauer, and others, called attention to the need of such instrumental comparisons, and so various resolutions on this subject were passed by the Magnetic Commission of the International Meteorological Committee, which have recently been put into effect by various countries. The present contribution records the results obtained by the Carnegie Institution of Washington in the course of its magnetic operations, and under the direction of Dr. Bauer. The accuracy here striven for is that which, in general, will be amply sufficient for ordinary magnetic survey purposes.
Die erdmagnetischen Elemente in Tsingtau, China
Authors: Meyermann B.
Published: February 2008

Die nachstehenden erdmagnetischen Elemente sind die ersten Resultate der Beobachtungen mit dem kürzlich hier eingetroffenen Stationstheodolit von Tesdorpf. Obschon es sich nur um einige Tagesmittel handelt, an die eventuell noch kleine Korrektionen anzubringen sind, möchte ich die Daten doch umgehend veröffentlichen, da sie vielleicht schon Verwendung finden können. Für Anfang März 1912 ist der Tageswert in:Deklination Inklination IntensitätDI Horizontal (H) Vertikal (Z)3° 59′.0 W 52° 05′.7 N 0.30886 0.39668
Regarding magnetic records obtained in co‐operation with Captain Scott's Antarctic expedition
Authors: Chree Charles
Published: February 2008

I have been instructed to request Directors of all observatories which have taken part in the programme of special magnetic observations on term hours between May 22, 1911, and January 26, 1912, agreed on with Captain Scott, to kindly send to Kew Observatory, Richmond, Surrey, England, copies (preferably photographic) of the records obtained during all the term hours. Directors are also requested to send information as to any errors in the time marks on the traces, and as to base line values and scale values with explanations of what increasing ordinate signifies in the several curves, and of how the curves should be measured (e.g., whether from the upper edge of base line to upper edge of trace, or otherwise). Information is also desired as to temperature corrections, if these vary sensibly during any of the term hours. It would also be a convenience to have any information that is readily available as to the changes to be expected (from the regular diurnal variation) on a normal day during the respective term hours.
On the moment of inertia of long magnet H26 at the Cheltenham Observatory
Authors: Faris R. L.
Published: February 2008

On pages 45–46 of the March 1912 number of this Journal, attention was called to the difference between the values of the moment of inertia of a magnet as computed from its dimensions and mass, and as determined experimentally with the aid of an auxiliary inertia weight, and the statement was made that in each of the four cases mentioned where such differences were shown the magnet house of the magnetometer used was of brass, so that any effect due to impurity or damping might affect the experimentally determined results.

At the suggestion of the Editor of this Journal it was decided to test this matter experimentally for the long magnet of Magnetometer No. 26, the standard instrument of the Cheltenham Magnetic Observatory.
The theory of the Earth inductor as an inclinometer
Authors: Dorsey N. E.
Published: February 2008

The earth inductor, in its most complete form, as used for the measurement of the magnetic inclination, consists essentially of a coil (Crpar; of insulated wire which can be rapidly and continuously rotated about an axis (ABrpar;, Fig. 1, which coincides with a diameter of the coil. The axis AB is capable of measured rotation about the two mutually perpendicular axes, one horizontal, DE, and the other vertical, V; by construction AB is perpendicular to DE. Thus the direction of AB can be made to coincide with that of any radius of a sphere having its center at the intersection of the three axes. In the future we shall speak of AB as the axis of rotation, of DE as the inclination axis, and of V as the azimuth axis, and shall call the plane which includes both AB and DE the “inclined plane” of the instrument.
Einige Bestimmungen der Aktivität der Luft in der Nähe der Südchilenischen und Argentinischen Küste
Authors: Knocke Walter
Published: February 2008

Von der Leitung des Department of Terrestrial Magnetism (Carnegie Institution of Washington) beauftragt, luftelektrische Messungen während der totalen Sonnenfinsternis im Staate Minas Geraes (Brasilien—10, Okt. 1912) auszuführen, bot sich mir—die Kordillereneisenbahn war wegen gewaltiger Schneefälle ausser Betrieb—willkommene Gelegenheit, auf der Dampferfahrt nach Rio einige Messungen der induzierten Aktivität der Luft auszuführen. Während ich im März‐Mai 1911 Gelegenheit hatte, derartige Bestimmungen auf einer Fahrt nach der Osterinsel,1 also in landfernen Gebieten zu machen, kamen diesmal küstennahe Gewässer in Frage. Um eine Vergleichbarkeit dieser Messungen mit den erwähnten zu erreichen, wurde ganz in der gleichen Weise mit den gleichen Instrument gearbeitet (auf der Brücke des P.M. S. Oronsa); ich brauche daher die Art der Messung hier nicht wiederholen.

Die Tabelle auf Seite 72 enthält in der ersten Spalte den ungefähren Schiffsort während der Beobachtung nach der Kartenskizze; sie enthält ferner das Datum, die Zeit der Exposition, den Elster und Geitelschen Wert A für 3 Min. nach Beendigung der Ladung, die Entfernung vom nächsten Landpunkt in km, Windrichtung und Stärke (Beaufort) und schliesslich f¨r einige Fälle das Resultat der Kurvenanalyse, d. h. den prozentualen Gehalt an Radium und Thoriuminduktionen.
On an auroral expedition to Bossekop in the spring of 1913
Authors: Störmer Carl
Published: February 2008

The following is a short account of a new auroral expedition which I made to Bossekop in the spring of 1913 for the purpose of completing the results of my expedition to the same place in 1910.

My assistant was the meteorologist, Bernt Johannes Birkeland, who also went with me in 1910, and is going with Roald Amundsen's expedition across the North Polar basin.
Magnetic and electric observations at Kew Observatory relating to the solar eclipse of August 21, 1914
Authors: Chree C.
Published: February 2008

The following data (magnetic and electric) relate to the solar eclipse on August 21, 1914, and adjacent days.

In what we did we were partly determined by the circular from Dr. Bauer, and partly by one on behalf of Mr. Carlheim Gyllensköld, who is also interested in the matter. We had only one Ebert apparatus available; our second one was temporarily at Eskdalemuir. It thus appeared best to limit ourselves to collections of positive ions. The Wilson apparatus, which was simultaneously under observation, was used to get a measure of the air‐earth current. The potential‐gradient data were derived from the water‐dropper curves. Normally we observe only at 3 p. m., with the Wilson and Ebert apparatus. But special observations were taken on August 17, 18, 19, 20, 22, and 27, covering the eclipse hours, so as to get comparative data.
Status of reduction and publication of the magnetic observations made on Amundsen's Northwest Passage
Authors: Steen Aksel S.
Published: February 2008

You ask to be informed how soon the magnetic observations made by Captain Amundsen on his Northwest Passage will be published. With the aid of two assistants, I am still working out the large mass of material, consisting of the absolute observations of the three magnetic elements and of the magnetograph registrations.

I intend to publish hourly values, local time, for H, D, V, obtained from the magnetograms, and the mean values of the ordinates for every one hour's interval, Greenwich time, 19 months at Gjöahavn, and 6 months at Kings Point. All of the magnetograms, 720 daily plates, will be reproduced in natural size.
Investigations with regard to the effect of the induced charge on the Ebert electrometer at Kew Observatory
Authors: Nichols E. H.
Published: February 2008

For a normal positive electric field surrounding any earthed body placed above the surface of the ground there is an induced negative charge on the body, increasing with its capacity and the potential gradient. Dr. W. F. G. Swann1 has attempted to estimate the effect of the induced charge on the Ebert electrometer. According to his reasoning, this decreases the measured ionic density of the negative ions, that of the positive remaining unaffected. He claims that with an air flow of 1.5 liters per second, and a potential gradient of 70 volts per meter, there would be an error of 26 per cent in the values obtained for the negative ions.
Magnetic observations at De Bilt relating to the solar eclipse of August 21, 1914
Authors: van Dijk G.
Published: February 2008

According to Dr. Bauer's circular of June 23, 1914, the following is a report on the observations at De Bilt (52° 06′ N, 5° 11′ E) during the solar eclipse of August 21, 1914. A method of illumination (see Terr. Mag., vol. 15, 1910, p. 31), differing from the usual one, is applied for the Adie‐magnetograph. A contact clock closes the circuit of a battery for two seconds every minute, the current lights a little glow‐lamp and thus forms a small line or spot, about 1/2 mm. long and 1/8 mm wide, on the paper. The recorded curve consists of a series of points 1/4 mm. apart; the time scale is 15 mm. to the hour.
On the conduction of electricity through an ionized gas, more particularly in its relation to Bronson resistances
Authors: Swann W. F. G. , Mauchly S. J.
Published: February 2008

In many radioactive investigations in which the measurement of small currents is involved, the principle of allowing the current to enter an electrometer and escape through a standard high‐resistance has been adopted, the deflection attained by the electrometer in the equilibrium state being the quantity which is directly measured, and which is proportional to the current sought, when the standard resistance obeys ohm's law. Bronson2 has developed a convenient type of resistance in which the air between two parallel plates is rendered conducting by covering one of the plates with a layer of polonium. These resistances obey ohm's law over a considerable range, but their magnitude is such that for plates of 5 or 6 sq. cm. cross‐sectional area they give currents of the order of magnitude of 10‐2 E. S. U. for potential‐differences of 3 volts. For some purposes very much higher resistances are required, as for example when the current to be measured is very small and the conditions are nevertheless such that it is undesirable to make the electrometer very sensitive.
Results of observations of earth currents made at Jersey, England, 1916–1917
Authors: Dechevrens Marc
Published: February 2008

The results were obtained by making electrical connection, through a galvanometer, between the gas‐pipe system of the city of St. Helier, Jersey, and the water system (800 or 900 meters of galvanized iron pipe) of the Observatory St. Louis. The galvanometer used in the observations for the year 1916–1917 was of the moving‐coil type and was constructed at the Observatory. The resistance was about 150 ohms. At a distance of 30 cm from the mirror, a deflection of 1 mm corresponded to a potential‐difference of 0.002 volt between its terminals.
Instructions issued by France and United States concerning protection of Cook's third expedition, returning to England
Authors: Edmonds H. M. W.
Published: February 2008

The following extracts from Arthur Kitson's book “Captain James Cook, R. N., F. R. S. The Circumnavigator,” pages 355–356, will be of interest:

“It may conveniently be noted here that, on the arrival of the Resolution and Discovery at Macao, on their way home in 1780, they were informed that England was at war with France and the American colonies; so to preserve a record for the Admiralty in case of capture, Burney made a copy of the whole of his log on thin Chinese paper. This copy is in the British Museum, and is written on both sides of sheets of paper, folded many times, in a clear hand, but so small as almost to require a magnifying glass to decipher it. This precaution was in reality unnecessary, for on the declaration of war the French Minister, M. de Sartines, wrote the following instructions to the Navy:
The secular variation of terrestrial magnetism in Siberia
Authors: Weinberg Boris
Published: February 2008

There exists no summary of magnetic determinations actually made in Siberia. Hansteen's “Untersuchungen ueber den Magnetismus der Erde” is now quite out of date, and Sabine's classical “Contributions to Terrestrial Magnetism,” No. XIII, did not comprise the considerable amount of observations made in the first half of the seventies of the last century by Fritsche, Miller, and Scharnhorst, and, in this century, by Voznesenskij, Smirnov, the Author and his co‐workers, and by other observers.

The insufficiency of even Sabine's work now can be easily seen, for instance, from Table I, which gives the number of magnetic observations in the zone of Siberia between parallels of latitude 45° and 60° North and between the meridians 60° and 135° East of Greenwich, either published or in press; D denotes the magnetic declination, I, the inclination, and H, the horizontal intensity.
Results of atmospheric‐electric observations made at Sobral, Brazil, during the total solar eclipse of May 29, 1919
Authors: Mauchly S. J. , Thomson Andrew
Published: February 2008

1. In accordance with the general plan of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington for making magnetic and atmospheric‐electric observations to determine the nature and magnitude of the respective effects associated with solar eclipses, parties equipped for this purpose were sent by the Department to several points located in the belt of totality of the solar eclipse of May 29, 1919. One of these parties, in charge of Mr. D. M. Wise, proceeded to northeastern Brazil, where it was thought possible, from a consideration of the various factors entering into the matter, to find a suitable location. Fig. 1 shows the general relation of this region to the eclipse and especially to the belt of totality.

LOCATION OF STATION AND LOCAL CIRCUMSTANCES OF ECLIPSE.
Concerning magnetogram‐scalings at Lukiapang Magnetic Observatory
Authors: de Moidrey J.
Published: February 2008

1. In January, 1917, we began scaling our magnetograms with mean scales very similar to those described by Mr. Fleming.1 The 60‐minute interval is counted from 0h 0m. But unfortunately, owing to the lack of personnel, it has been necessary to diminish the work. In consequence, the day is not divided into 24 hours, but into six intervals of 4 hours, the centers of which are 2h, 6h, 10h, 14h, 18h, and 22h.
Magnetic observations at Bulawayo, May 28–30, 1919
Authors: Goetz Rev. E.
Published: February 2008

Below are given the results of the magnetic observations which I took on May 28, 29, and 30, 1919, in connection with the solar eclipse of May 29, 1919, and in accordance with the program and forms received from the Department of Terrestrial Magnetism.

I think I made a mistake in undertaking too much. After sixteen years of continued stay in this country one ought not to do things which are quite possible to a younger man and not expect to feel it. On the 29th I was very tired. I had given up the idea of taking contact observations. At the last moment a friend offered to take them, and I tried to get my telescope ready for him. Unhappily the 29th turned out to be a cloudy day. From 9 to 11 o'clock (local time), I tried in vain to focus my telescope for him at rare moments when I got a fleeting glimpse of the Sun. At eleven I gave it up and went back to my magnetic hut. I found the fiber broken. I had prepared for this emergency. But as the morning was very windy the new fiber developed a twist which took the better part of the hour to get rid of. In consequence I fear my preliminary determinations were rather hurried.
Magnetic observations at Agincourt and Meanook, May 29, 1919
Authors: Stupart F.
Published: February 2008

[The data supplied for the Agincourt Magnetic Observatory, near Toronto, Canada, consisted of eye‐reading values of magnetic declination (D), horizontal intensity (H), and vertical intensity (Z), for every minute, 9h 58m to 16h 32m, Greenwich civil mean time, May 29, 1919. For the Meanook Magnetic Observatory similar data could be supplied only for D. Tables 1 and 2 contain the derived five‐minute means. Furthermore, the mean diurnal variation for May 28 and 30, 1919, was transmitted (Table 3). Later were received also the hourly magnetograph values for May 28–30, 1919, from which Table 4 was derived.