bluuebunny/crossref_metadata_2025 huggingface dataset:
Alibag Magnetic Observatory
Authors: Moos N. A. F.
Published: February 2008

Early in 1900 the city of Bombay finally decided to employ electricity as motive power for its street tram service. Magnetic work, hence, which had run uninterruptedly for over fifty years by then at the Bombay Observatory, was thus threatened by the proposed introduction of the. electric traction, and prompt action in the interests of the Observatory seemed essentially urgent. Efforts to find some modus vivendi which might allow this work to be continued at the Observatory without serious vitiation from the disturbing effects of the lines, having proved abortive, no alternative seemed possible but to remove the magnetic work to some suitable site in the neighborhood. It became imperative under the circumstances to make provision without delay for the establishment of the new Observatory at some protected site elsewhere, which might allow comparative observations for a fairly long period to be made at the old and new sites before the conversion of the ordinary tram‐lines into electric traction was completed, and enable, if possible, the continuity of the Bombay record to be preserved.
Ueber die gegenseitige Einwirkung zweier Magnete in beliebiger Lage: Schluss
Authors: Von Ad. Schmidt
Published: February 2008

Die Voraussetzungen, die den in der Praxis vorwiegend benutzten speziellen Fällen zu Grunde liegen, sind natürlich nie streng erfüllt. Man muss daher noch den Einfluss der möglichen Abweichungen untersuchen, einerseits, um festzustellen, unter welchen Bedingungen dieser Einfluss unmerklich ist, andererseits, um ihn eliminieren oder durch Korrektionen unschädlich machen zu können, wenn er nicht mehr vernachlässigt werden darf. Dazu muss man natürlich auf die allgemeinen Formeln zurückgreifen, und gerade darin liegt ein Hauptgrund dafür, dass man diese abtelten muss, obgleich anscheinend spezielle Formeln für alle praktischen Aufgaben genügen. Dieser Umstand hat keineswegs iraruer die gebührende Beachtung gefunden, und es ist ein besonderes Verdienst der Arbeit. von Leyst, dass diese darauf ausführlich und mit grundsätzlicher Betonung eingeht.
Preliminary isogonic chart of northern Asia for 1909.5
Authors: Weinberg Boris
Published: February 2008

This preliminary chart was constructed mainly for the purpose of elucidating the question in what directions it is desirable first to supplement the existing data by additional magnetic expeditions. It is based only on the observations made during the past 17 years, since, on account of the uncertainty in our present knowledge of the secular change, it is not deemed safe to make use of the data prior to this period.
Results of magnetic observations made by the United States Coast and Geodetic Survey at the time of the solar eclipse of June 8, 1918
Authors: Hazard D. L.
Published: February 2008

In response to the request of Dr. L. A. Bauer, director of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, for additional data for the study of the effect of an eclipse of the Sun upon the Earth's magnetism, the Coast and Geodetic Survey arranged to have special observations made at 3 field stations in the belt of totality. Eye readings of declination were made every minute for six hours beginning at 7 P.M., Greenwich mean time (Table 4). For a period of 20 minutes about the time of totality, eye readings were made every 30 seconds. Temperature readings were made every 5 minutes (Table 5).
The magnetic character for the year 1918
Authors: Van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1918 has been drawn up in the same manner as the preceding year. Thirty‐eight observatories contributed to the quarterly reviews; 34 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 on page 134.
Ein Mangel der erdmagnetischen Jahrbuecher
Authors: Schmidt Adolf
Published: February 2008

Um dem Verständnis und der Erklärung einer verwickelten Erscheinung, wie es der Ablauf der erdmagnetischen Vorgänge ist, näher zu kommen, hat man vor allem ihre Zerlegung in einfachere, wenn möglich selbständige, aus verschiedenen Ursachen entspringende Teile zu erstreben. Freilich setzt eine vollkommen zutreffende derartige Zerlegung schon die Kenntnis der doch erst das Endziel der Forschung bildenden Ursachen der Erscheinung voraus, so dass man sich auf diesem Wege anscheinend im Kreise bewegt. Aber bei zweckmässigem Vorgehen kann dieser doch zur Spirale werden, die sich dem Ziele mehr und mehr nähert. Das ist am ehesten möglich, wenn sich die Teilerscheinungen in ihrem zeitlichen oder räumlichen Charakter deutlich von einander abheben, so dass man sie zunächst wenigstens nach formalen Gesichtspunkten trennen kann.
The normal distribution of terrestrial magnetism over Siberia in 1910
Authors: Weinberg Boris
Published: February 2008

1. This article is based on my three unpublished investigations on the distribution of the inclination,21 of the declination,26 and of the horizontal intensity27 over Siberia, and is published in somewhat different form in Russian.30 The publication of the Russian abstract, instead of the three quoted articles in extenso, was necessitated on the one hand by my proposal of a magnetic survey of Siberia,29 and by the desirability of having data on the distribution of terrestrial magnetism over Siberia in connection with the actual conclusion of the general magnetic survey of the globe by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington on the other hand. If Asiatic Russia, which covers over a ninth part of the land area of the globe, occupies the last place in the list of the large continental countries as concerns magnetic surveys, this defect can partly be compensated for by summaries of all determinations of the magnetic elements thus far made and by theoretical investigations based on the results obtained. The paucity of distribution of magnetic stations over even such easily accessible parts of Siberia as the provinces of Akmolinsk and Semipalatonsk was shown by me in a special paper with its accompanying chart.8
Regarding magnetic work in Norway
Authors: Saeland Sem
Published: February 2008

I have the pleasure to give you the following information as to the present magnetic work in this country.

The Haldde Observatory is regularly carrying on magnetic observations and photographic registrations, but no publication of the results has thus far appeared, and moreover I fear that the absolute measurements and the determinations of the constants of the instruments, as well as the value of the base‐line of the registration curves, have not been made regularly and with the accuracy demanded in modern magnetic work. The registration instruments used at Haldde are of the Eschenhagen type. As far as I know they have a double set of such instruments, but none for eye readings. For the absolute measurements the Haldde Observatory possesses an instrument from the firm Tesdorpf in Stuttgart; this instrument is designed, not as a first‐class station instrument, but for survey work.
Records of Principal Magnetic Storms and of earthquakes at the Watheroo Magnetic Observatory, April to June, 1924
Authors: Johnston H. F.
Published: February 2008

(Latitude, 30° 19′.1 S.; Longitude, 115° 52′.6, or 7h 44m E. of Greenwich.)
Note on a radio method of estimating the height of the conducting layer
Authors: Tuve M. A. , Breit G.
Published: February 2008

The method presented below has developed out of a discussion of a method which has been thought of and tried out to some extent by Professor W.F.G. Swann and Dr. J.G. Frayne at the University of Minnesota. The idea used by Swann and Frayne was to interrupt the continuous waves of a transmitting station and to interrupt the action of a receiving set in such a way as to have the receiver out of adjustment when the station is sending and to have it in adjustment when the station is not sending. With a suitable frequency of interruption the waves were expected to be received from the layer by the receiver when it was in adjustment even though there should be no waves directly from the transmitter. These experiments have not been carried to completion.
Principal magnetic storms at the Cheltenham Magnetic Observatory, October to December, 1924
Authors: Hartnell Geo.
Published: February 2008

The only notable magnetic disturbance during the quarter was that beginning October 23 at 17h G.M.T. and ending October 24 at 11h G.M.T., with ranges as follows: Declination, 25′.6; horizontal intensity, 119γ; vertical intensity, 113γ.
Observed sunspot relative numbers, 1749–1924
Authors: Wolfer A.
Published: February 2008

[The foregoing Table contains the final and revised numbers according to Wolfer, who kindly supplied also, in advance of regular publication, the final numbers for 1923 and 1924. For the general method of deriving these numbers, the interested reader may be referred to the various issues of the Astronomische Mitteilungen, begun by Wolf and continued by Wolfer. The Table is printed here in view of the numerous requests for the final values of these measures of solar activity,—Ed.]
The 27‐day recurrency in Earth currents
Authors: Peters W. J. , Ennis C. C.
Published: February 2008

Dr. Chree and others1 have shown by statistical investigations the recurrence of average high and average low values on the 27th day after days of selected highest and selected lowest in long unbroken records of magnetic measures, such as the international character numbers and the daily ranges in magnetic elements. The high correlation found by Dr. Bauer2 between the variations, diurnal and annual, in terrestrial magnetism, atmospheric electricity, and earth‐currents indicates the desirability of applying to these related phenomena the same statistical method of searching for a 27‐day recurrency.

Accordingly the subject of this paper is a description of the process as applied to the earth‐current observations published in the bulletins of the Ebro Observatory in Spain from 1910 to 1924 inclusive and the exhibition of the results.
Studies concerning the relation between the activity of the Sun and of the Earth'S magnetism:—No.III
Authors: Bauer Louis A. , Duvall C. R.
Published: February 2008

The annual variation of magnetic activity is investigated with the aid of various measures, chief of which is a quantity, F, giving the number of days per month of magnetically‐disturbed days from 1906 to 1924. The average number of such days per month, Fi, during the sunspot minimum years was 4.4, and during the years of sunspot maximum, Fx was about 10; hence, Fx was only 2.3 Fi. During a solar cycle there may be, on the average, about 7 magnetically‐disturbed days per month.

For the period 1906–1924, F showed maxima values (about 9.2 days) in the equinoctial months and minima values (about 5.8 days) in the solstitial months; the ratio 9.2/5.8 = 1.6. The marked change in F from month to month cannot be successfully correlated with varying sunspottedness during the year. The correlation coefficient between the F‐measures and the cosine of the Sun's declination is +0.95, and that between F and the cosine of the Earth's heliographic latitude is −0.82; in the first case we have a direct (+) correlation, and in the second an inverse (−) correlation.
Preliminary comparison of atmospheric‐electric potential at sea with that under closely similar insular conditions at Apia, Western Samoa
Authors: Thomson Andrew
Published: February 2008

The electric potential of the atmosphere has been measured at Apia (latitude 13°.8S., longitude 171°.8W.) for 19 years1, and on account of the unique position of the Observatory on a small island in the Pacific Ocean, special interest has been attached2 to the results in giving information concerning the great water‐covered areas of the Globe. In order to approximate more closely to oceanic conditions, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington erected, in 1923, above the waters of the lagoon, a special observation‐house about 500 meters from the shore. The house is on the north side of the island, in a position exposed to the winds, but protected by a narrow ridge of coral reef from the action of the waves of the open ocean. The Southeast trades, shifted by local conditions so that they blow parallel to the north coast of the island3 have not passed over land before striking the lagoon house, and the atmosphere, being that of an oceanic island, is free from dust or pollution.
Principal magnetic storms recorded at the Apia Observatory, April to June, 1926
Authors: Thomson Andrew , Westland C. J.
Published: February 2008

(Latitude, 13° 48′.4S.; longitude, 171° 46′, or 11h 27m.1W. of Greenwich.)

April 14, 1926.—This storm is the largest experienced at this Observatory since May, 1921. A sudden commencement begins on April 14 at 14h 00m, Greenwich mean time, the maximum value of H being 35255γ at 14h 17m on April 14 and the minimum value, 34929γ at 7h 28m on April 15. About 15h on April 15 the curve becomes smoother. April 16 and 17 are both days of character 2, although the ranges on these days are not exceptional because the curve remains low all the time.
The times of recent “sudden commencements” of magnetic storms at Eskdalemuir
Authors: Absalom H. W. L.
Published: February 2008

The publication by Dr. R. Bock of the times of several recent “sudden commencements” of magnetic storms registered at Potsdam, by means of recording arrangements permitting a more accurate determination of occurrence than those in everyday use at most magnetic observatories, suggests that similar information from another observatory may be of interest.

Although there is at present at Eskdalemuir (lat. 55° 19′ N.; long., 3° 12′ W.) no means of obtaining continuous open time‐scale registration of the horizontal force or declination, it is possible to give for the last five of the Potsdam cases, and with at least as much accuracy, the times of the “sudden commencements” in the vertical component. These times are derived from records of the rate of change of vertical force, the records being obtained from a sensitive moving‐coil galvanometer connected to the ends of a coil of insulated wire resting in an approximately horizontal plane. The resistance of the circuit is such that the galvanometer is adjusted to critical aperiodicity. This method of registering small changes in vertical force was introduced at Eskdalemuir by Dr. A. Crichton Mitchell some eight years ago, but it is only since the end of January, 1926, that records have been obtained continuously. Particulars of the arrangements and a description of the changes in vertical force during a small “sudden commencement” at 1924, September 4, 5h 45.3m G. M. T., have already been published. For the present purpose it is sufficient to state that on the photographic record the time‐scale is about 10 millimetres to 1 minute, and that a deflection of about 6 millimetres is produced by a rate of change in vertical force of 10−7 c. g. s. per second. Short time‐gaps every minute, and somewhat longer gaps every hour, are made on both the base line and the trace of the galvanometer deflection by an electromagnetic shutter actuated by a contact‐clock which is rated from daily time‐signals from Greenwich. The time of occurrence of a reasonably well‐defined movement on the record can be assigned to well within 0.1 minute.
Eintrittszeiten erdmagnetischer Störungen, 1925 und 1926
Authors: Bock Von R.
Published: February 2008

Im Heft 3 des Bandes 31, in dem ich die Eintrittszeiten der erdmagnetischen Störungen aus den Jahren 1925 und 1926 nach den Potsdamer Registrierungen mitteilte, befinden sich gleiche Zusammenstellungen anderer Observatorien für das 2. Vierteljahr 1926, die zum Vergleich der angegebenen Zeiten anregen. Hierbei fällt nun besonders auf, dass das Apia Observatorium Samoa für die Störung vom 3. Mai als Ausbruchzeit 22h 50m angibt.
Latest annual values of the magnetic elements at observatories
Authors: Fleming J. A.
Published: February 2008

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Recent magnetic disturbances at Godhavn
Authors: la Cour D.
Published: February 2008

Dr. Olsen has sent me by wireless the times of commencement of some recent disturbances. I am unable at the present moment to give further details concerning the beginnings of the disturbances, but in view of the very exact times for which the information from Godhavn is given and considering the high magnetic latitude of that observatory and the lack of similar information from corresponding latitudes the whole minute of the times may already be of some preliminary interest.
Preliminary note on electromotive forces possibly produced by the Earth's rotating magnetic field and on observed diurnal‐variation of the atmospheric potential‐gradient
Authors: Wait G. R. , Sverdrup H. U.
Published: February 2008

The first part of the paper contains a formal computation of the electromotive forces which would be induced, under certain hypotheses, at the magnetic poles of the Earth on account of the rotation of its magnetic field. Supposing that these electromotive forces act upon charged particles entering the upper atmosphere and coming from the Sun, it is possible to compute an incoming “current.” The principal assumptions are: (1) That charged particles of a given sign are accelerated towards the Earth when the electromotive forces have certain directions referred to the relative position of Sun and Earth, and (2) that the effect is of equal magnitude along the three rectangular axes. The “current” thus computed shows a diurnal variation and annual variations of phase‐angle and of amplitude which are in remarkable agreement with corresponding variations of the atmospheric potential‐gradient as actually determined from observations made at sea by the Carnegie, in the Arctic by the Maud Expeditions, and at certain land stations. This agreement appears too good to be accidental; it is difficult, however, to develop a physical basis to explain relation between the two phenomena.
Magnetic observations in Spitzbergen in 1927
Authors: Woolley R. v. d. R.
Published: February 2008

The following observations were made by the writer of this article while a member of a Cambridge University expedition to Edge Island, the southeast member of the Spitzbergen group, in July and August 1927. The instruments used were a Kew pattern unifilar magnetometer, by Dover, Charlton (No. 161), a 3‐inch theodolite (used in some of the declination observations), and a chronometer which was checked by wireless time‐signals.

Values of horizontal force were observed at six stations grouped round Stor Fiord, three on the islands and three on the mainland of Spitzbergen. The procedure adopted in every case was to perform successively vibration, deflection (30 cm.), deflection (40 cm.), deflection (30 cm.), and vibration experiments. Before leaving England the instrument was compared with the standard instruments at Abinger and a satisfactory agreement obtained. The declination was observed at seven separate stations, usually at intervals whenever convenient during the horizontal‐force experiment. Very little meaning can be attached to a single observation of declination in these latitudes, but by taking observations over two hours on a quiet day a mean value can be found. On very quiet days the needle may not move through more than three or four minutes of arc during two hours. The Sun was used for all azimuths, which were sometimes determined with the theodolite and sometimes with the magnetometer‐attachment.
Provisional sunspot‐numbers for May to December 1927
Authors: Wolfer A.
Published: February 2008

The provisional sunspot‐numbers for December, 1927, cover only twelve days; however, since these are fairly well distributed over the month, the monthly mean is probably not far from the truth, the fluctuations in activity being small. The yearly mean of the provisional sunspot‐numbers derived from 297 days for 1927 is 67.8, and is only about five units greater than the mean provisional sunspot‐number (62.4) for 1926.
The origin of the Aurora Borealis
Authors: Hulburt E. O.
Published: February 2008

A theory of the aurora borealis has been developed by Birkeland, Störmer, Vegard,1 and others on the assumption that the aurora is caused by charged particles emitted from the Sun which under the influence of the magnetic field of the Earth are diverted to the polar regions. There their energy is given to the atmosphere and by some process is converted partially or totally into the auroral light. In the theory a difficulty has existed for a long time which, it must be said, has not been very troublesome because of the rather tentative nature of the theory. If the charged particles are a‐particles or ions of some sort they do not combine a sufficient penetrating power with a sufficient magnetic deflectibility to explain the height and structure of the aurora,2 and if they are electrons their penetrating power may be too great.3
Note on some photographs of lightning‐discharges made at the Huancayo Magnetic Observatory
Authors: Parkinson W. C.
Published: February 2008

The photography of lightning‐discharges affords valuable data for the solution of some fundamental problems in atmospheric electricity. In this note description is given of the methods used to obtain photographs on motion‐picture film of lightning flashes at Huancayo, a location very suitable for this work. Specimen photographs are given and briefly discussed and the necessity for further work indicated.
Summary of magnetic‐survey work by the Carnegie Institution of Washington, 1905–1926
Authors: Fleming J. A. , Fisk H. W.
Published: February 2008

The general magnetic survey of the globe, to the accomplishment of which the Carnegie Institution of Washington, through its Department of Terrestrial Magnetism under the energetic guidance of Director Louis A. Bauer, devoted its energies for many years, has been completed for the major part of the Earth.1 While this task has been accomplished through the labors of the Department, these were directed chiefly to the ocean areas and to those countries or regions for which magnetic data would not otherwise be obtained promptly. In some regions, required magnetic surveys were accomplished by cooperation with existing organizations or with interested investigators. Valuable data in polar regions have been obtained by successful cooperation with the Peary Arctic Expedition, the Mawson Antarctic Expedition, the Amundsen Arctic expeditions, and the Baffin Land and North Greenland expeditions of Dr. Donald B. MacMillan.
Method for measuring the susceptibility of rocks
Authors: Koenigsberger J. G.
Published: February 2008

Lord Kelvin's mathematical method of electrical images applied to a magnet gives the susceptibility of a body haying a plane surface placed near the magnet. The different corrections for varying distance, finite surface area, and finite height perpendicular to the surface are discussed. The method is suitable for use in the field with a variometer to determine the susceptibility of samples of rocks. Crystalline schists and other rocks often exhibit a magnetic anisotropy. A provisional scheme for a magnetic‐geological classification of rocks based on remanent magnetism is given. The order of magnitude of remanent induced KF is compared with present values.
A leak‐free method of measuring air‐potentials
Authors: Gish O. H. , Sherman K. L.
Published: February 2008

The advantage of null methods of measurement is generally appreciated by physicists. Another device of great service in certain classes of electric measurements is the guard‐ring. These two devices were embodied in an arrangement designed by the senior author for the purpose of eliminating errors which are likely to arise in certain types of atmospheric‐electric measurements from inadequate insulation. These errors are difficult to detect unless they amount to 20 per cent or perhaps considerably more.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

The Department has suffered an irreparable loss in the death, December 24, 1928, of Dr. Sebastian J. Mauchly, Chief of the Section of Experimental Work in Terrestrial Electricity. Since 1914, he devoted his attention in the Department to problems of terrestrial electricity and the development of instruments and methods for measuring its elements. Among his important contributions is the discovery of the universal 24‐hour term in the diurnal variation of the potential gradient of the Earth's electric field, disclosed from discussions of the Carnegie results and confirmed by an extensive examination of records obtained at widely distributed land stations. Apart from his scientific attainments, his loss is also keenly felt by his colleagues and friends because of his attitude of helpful service and his charming personality.
Sitka Magnetic Observatory October to December, 1929
Authors: Ulrich Franklin P.
Published: February 2008

October 7–9, 1929—This magnetic storm might be classified as three separate storms as it was active at three different times with character 2 and curves of character 1 between them. The storm had a gradual beginning lasting a few hours, and from 11h 30m to 14h 30m the storm was very active with large ranges in all of the curves. This is followed by rapid fluctuations of smaller range for about seven hours. From 8h 30m to 12h October 8 the storm was active again and also from 8h to 14h October 9.
A note on two apparent large temporary local magnetic disturbances possibly connected with earthquakes
Authors: Chapman S.
Published: February 2008

(1) The two reports from ships, reproduced and discussed in this Note, were communicated to me by Professor H. H. Turner (President of the Section of Seismology of the international Union for Geodesy and Geophysics), with the suggestion that they were worth bringing to the notice of workers on terrestrial magnetism.

I—(From Seismological Despatches, Georgetown, U.S.A., 1926, August 3., S.S. West Holbrook.)

“While the above‐named vessel was entering the Gulf of Tokyo, 6:40 P.M. A.T.S. (apparent time of ship), on the above‐named date, a slight tremor was felt, as if vessel was grounding. Vessel shivering and a noise was heard, as if touching a rocky ledge, but no reduction in speed could be noticed.

“Vessel heading at the time 328° P.S.C., 319° true. Deviation 3.°6 west on course.

“Bearings were immediately taken of Suno Saki Light bearing north 26° east true, and Merano Hana Light bearing north 93° east true; which placed vessel in latitude 34° 55′ north, longitude 139° 43′ 30″ east, and by chart in from 46 to 50 fathoms of water.

“From the above position to Yokohama, the ship's compasses were acting queerly, having on northerly courses a deviation of 0°.5 west; where before there had been 3° west.

“Upon arrival in Yokohama learned that an earthquake had taken place.

“The following morning, August 4, azimuths were taken for recording deviation. The compasses were still found to be out. On August 5 azimuths were again taken and compasses were now found to be back to normal.”
Variation of the compass south of Franz Joseph Land
Authors: Collinder P.
Published: February 2008

When navigating northwest of Novaya Zemlya and south of Franz Joseph Land the masters of sealing‐ vessels do not correct their courses for variation of compass, as it is said that their dead‐reckoning will be erroneous by the amount of variation corrected for.

On the motor‐cutter Björnöy, when proceeding from Admiralty Peninsula to 77° 30′ north, 59° 00′ east, thence to 78° 30′ north, 45° 00′ east, and thence to 77° 50′ north, 40° 0′ east, no correction for variation was used, and the courses laid down agreed well with astronomical positions.
Results of Earth‐current observations at Huancayo Magnetic Observatory, 1927–1929
Authors: Gish O. H. , Rooney W. J.
Published: February 2008

The apparatus and equipment used and the natural features concerned with the measurement of earth‐current gradients at the Observatory maintained by the Carnegie Institution of Washington near Huancayo, Peru, are described. A dual system of electrodes is installed and the potential differences are registered by a recording potentiometer. Although the region embraced by the measuring system is fairly flat yet evidence is found which indicates that the general northwesterly direction of water‐course and mountain ridges here doubtless influences the direction of the electric currents.

The character of the diurnal variation, as derived from records for all complete days, is exhibited by means of charts and tables and the Fourier coefficients of the diurnal variation are given for the three‐year means, for the means of individual years, and for the three‐year means grouped by months. The mean diurnal‐range of the northward component is 2.83 mv per km. The maximum occurs at 9h, the minimum at 15h (75° west meridian mean time) and the amplitudes during the hours of darkness are relatively small. The same description applies to the component at right‐angles to this (values being considered positive for currents flowing eastward) except that the mean range (3.26 mv per km) is somewhat greater. The direction of the current is northwestward from 2h.5 to 12h.5 and southeastward the remainder of the 24‐hour period. The times of the daily maximum and minimum are constant throughout the year, whi:h is contrary to the findings at Berlin, Ebro, and Watheroo. However, in general agreement with the results at these other places, the mean diurnal‐range changes with season, the principal minima (northward 1.89 mv per km, eastward 2.18 mv per km) occurring in June and maxima (northward 3.50 mv per km, eastward 4.00 mv per km) in March and October.

Disturbances (variations of relatively short and irregular period with amplitudes considerably greater, in the average, than those of the diurnal variation) predominate during the daylight hours.
Geophysikalische warte gross‐raum der Universität Königsberg in Preussen
Authors: Errulat F.
Published: February 2008

Die im Jahre 1912 begründete Hauptstation für Erdbebenforschung in Gross‐Raum der Albertus‐Universität Königsberg ist durch Anlage eines erdmagnetischen Observatoriums wesentlich erweitert worden und führt nunmehr die Bezeichnung Geophysikalische Warte. Die erdmagnetische Station verfügt über die Instrumente, die gelegentlich der erdmagnetischen Landesaufnahme von Hessen durch K. Schering und A. Nïppoldt die Einrichtung der Basisstation am Forsthaus Apfelbachbrücke bildeten, und zwar zwei von O. Toepfer und Sohn in Potsdam nach den Angaben von A. Schmidt gebaute Registrierinstrumente für D und H und eine in den Werkstätten des Physikalischen Instituts der Technischen Hochschule Darmstadt nach den Angaben von Schering gebaute Z‐Wage (vgl. Schering‐Nippoldt: Erdmagnetische Landesaufnahme von Hessen, Darmstadt 1923). Es wird jetzt in Gross‐Raum fortlaufend D, H, und Z registriert. Die Skalenwerte der Instrumente sind für D ca 1min/mm, für H und Z 6γ/mm, die Registriergeschwindigkeit beträgt 8.5 mm/h; sie muss leider so gering gehalten werden, da die Entfernung der Station von Königsberg Bedienung und Streifenwechsel nur an jedem zweiten Tage ermöglicht.
A new theory of magnetic storms
Authors: Chapman S. , Ferraro V. C. A.
Published: February 2008

Part I—The initial phase (Continued)

8—The conductivity, thickness, and density of the current‐bearing layer
Ein Vorschlag zur Ergänzung der magnetischen Jahrbücher
Authors: Fanselau Von G.
Published: February 2008

Für sehr viele magnetische Untersuchungen, die auf die Originalangaben der magnetischen Jahrbücher zurückgreifen, ist es ein oft sehr störend empfundener Übelstand, dass die von einer festen Abzugszahl aus gerechneten, veröffentlichten Werte durch die Säkularvariation besonders für weit auseinander gelegene Zeitpunkte ihre Vergleichbarkeit verlieren. Auf diesen Übelstand ist vor allem von Ad. Schmidt aufmerksam gemacht worden, auf dessen Veranlassung hin im Potsdamer Jahrbuch wohl auch zuerst diesem Umstand Rechnung getragen wurde.

Den Verfahren zur Elimination der Säkularvariation liegt gewöhnlich die Annahme eines zeitlich linearen Ganges dieser Erscheinung innerhalb eines Jahres zu Grunde. Diese Annahme ist in voller Schärfe sicher nicht erfüllt, und infolgedessen muss ein solches Eliminationsverfahren notwendig einige Unsicherheiten in sich tragen. Die explizite Berücksichtigung des säkularen Ganges während eines Tages ist daher im allgemeinen wohl kaum erforderlich, ganz abgesehen davon, dass die dann vielleicht zu bildenden Stundenkorrektionen in der weitaus grössten Mehrzahl der Fälle so klein sind, dass sie weit unter der bisher zu erreichenden Genauigkeit liegen. Hinzu tritt noch die eben erwähnte tatsächlich vorhandene Unsicherheit in der Erfassung der Säkularvariation, deren wahre Grosse kaum sicher genug abgeschätzt werden kann. Im allgemeinen erscheint es daher angebracht bei den Säkular korrektionen nicht über die Tageskorrektionen hinaus zu gehen. Um hier nun ohne viel Aufwand an Arbeit dem Benutzer die Möglichkeit zu geben, sich über die Grosse des säkularen Ganges zu orientieren, schlage ich vor, dass die Observatorien in ihren Jahrbüchern laufend eine Tabelle bringen, die die Säkularkorrektionen der zur Veröffentlichung gelangenden drei Elemente enthält gültig für die Mitte des Monats. Ferner in einer weiterer Tabelle die Tageskorrektionen für die Tagesmitte bezogen auf die bereits angegebenen Monatskorrektionen. Als Genauigkeit dieser Korrektionen dürfte wegen der bereits genannten Unsicherheit der Säkularvariation im allgemeinen 0′.1 bei den Richtungsangaben und ein γ bei den Kraftangaben ausreichen. Solche Tabellen sind aus Anlass einer grösseren Untersuchung über die Nachstörung am Potsdamer Observatorium für eine ganze Reihe von Jahrgängen verschiedener Observatorien berechnet worden. Sie werden demnächst gesondert für sich zur Veröffentlichung gelangen, um die hier einmal geleistete Arbeit auch für andere Untersuchungen nutzbar zu machen.
Auroral observations at the Alaska Agricultural College and School of Mines, 1930–31—Concluded
Authors: Fuller Veryl R.
Published: February 2008

Aurora journal, November 17, 1930, to April 17, 1931—The following pages summarize the journal of the photographic work done. Many of the photographs taken were either spoiled due to the plate‐holders leaking light, too short an exposure, or to the unusability of the negatives due to indistinct outline.

November 17, 1930: The aurora was first seen at 18:00 rather dimly as a narrow arc. Observers went to Station 2 but no pictures were taken because the aurora was too weak. It died out completely at 23:00. The sky became overcast about 24:00 and continued so during the remainder of the night.
Problems in atmospheric electricity at Apia, Western Samoa
Authors: Sanderson K. C.
Published: February 2008

Determination of influence of height of tide on reduction‐factor of Lagoon‐Station, August 3, 1931

All previous determinations of the reduction‐factor for the lagoon‐station at the Apia Observatory have been made either at Watson's Island, about one‐quarter mile east of the lagoon‐house, or in the lagoon southward from the main observatory buildings. The actual places used were in the first case a flat rocky shelf and in the other a flat stretch of sand both of which are laid bare at low‐tide. Since the flat stretches are covered with water before half‐tide, observations have thus been confined to low‐water or thereabouts. It was thought that the rise and fall of the sea‐level with the tide had no influence on the reduction‐factor on account of the concrete platform about eight feet square beneath the collector, which formed a permanent earth‐plane.
American URSI broadcasts of cosmic data
Authors: Clarke Katharine B.
Published: February 2008

The data for terrestrial magnetism, sunspots, solar constant, and aurora are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g + s), where k for Mount Wilson is about 0.77. The sixth and seventh columns show (1) the value in calories of the solar constant, and (2) by letters s, f, and u, whether the determination was satisfactory, fair, or unsatisfactory, respectively.
Período diurno, anual y secular en las perturbaciones súbitas del campo magnético terrestre
Authors: Rodés Por Luis
Published: February 2008

Amablemente inivitado por el Director del Departamento Magnético de la Carnegie Institution a colaborar al numéro extraordinario de Terrestrial Magnetism and Atmospheric Electricity que dicha Institución quiere dedicar a la memoria del malogrado Director, Dr. Louis Agricola Bauer, y recordando su constante interés y extensos trabajos en el estudio de los comienzos súbitos de las tempestades magnéticas, me ha parecido tomar como tema de esta brève comunicación el estudio de la frecuencia periódica con que se producen los saltos bruscos de los imanes en el registre del campe magnético.

Como base del estudio, el P. Puig ha recorrido todas las curvas del archive del Observatorio, unas 10,000 en conjunto, y de ellas ha entresacado 218 saltos bruscos, los cuales, clasificados por el mismo Padre siguiendo las indicaciones del autor de estas lineas, son analizados en este trabajo. Conviene notar que la seleccion se hizo con un criterio del todo ajeno al fin a que se destinaban, para evitar asi toda influencia de ideas preconcebidas.
Cheltenham Magnetic Observatory July to September 1932
Authors: Hartnell Geo.
Published: February 2008

(Latitude 38° 44′.0 N.; longitude, 76° 50′.5 or 5h 07m.4 W. of Gr.)
The temperature of the atmosphere at levels accessible to air‐waves
Authors: Whipple F. J. W.
Published: February 2008

At the end of his valuable paper1 on “The temperature of the auroral region,” Professor Vegard devotes a paragraph to sound phenomena and atmospheric temperature. He expresses the opinion that the propagation of sound to great distances can not be due to the existence of a warm layer in the atmosphere at a height of about 40 km. The only substantial basis for this opinion is a laboratory experiment indicating that, when a loud‐speaker and a microphone are set up in a vessel which can be evacuated, the transmission of sound fails at a pressure of the order one cm of mercury. This is an interesting experiment but, to my mind, it tells us more about the efficiency of loud‐speakers than about the transmission of waves through the free atmosphere.
American URSI broadcasts of cosmic data
Authors: Clarke Katharine B.
Published: February 2008

The data for terrestrial magnetism, sunspots, and aurorae are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Electricity, (2) the type featuring the day other than normal by letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N=k (10g+s), where k for Mount Wilson is about 0.77.
The effect of a solar eclipse on the Earth's magnetic field
Authors: Chapman S.
Published: February 2008

Summary—The reduction of ionization in the E‐layer, at a point on the track of the total eclipse of August 31, 1932, has been measured by Henderson; the effect of this on electron‐currents flowing in the layer is here examined, and the corresponding magnetic effects are inferred. If this layer is the seat of the currents which produce the solar diurnal magnetic variation (S), the magnetic effects of an eclipse should, it is inferred, be apparent, and their nature is described. If, however, S is produced in the upper (F) ionized layer, the eclipse‐effects are likely to be too small for detection with certainty. The magnetic observations during eclipses are discussed, and the opinion is expressed that they show no regular magnetic effect of the type here predicted, and that therefore 5 is probably not produced in the E‐layer; but a final decision must await further observations.
Provisional sunspot‐numbers August to November, 1933
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
A possible test for theories of magnetic diurnal‐variations and of magnetic storms
Authors: McNish A. G.
Published: February 2008

Three plausible theories1 have been offered to explain the magnetic diurnal‐variations—the atmospheric‐dynamo theory as suggested by Balfour Stewart and extended by Schuster and Chapman, the diamagnetic theory as outlined by Gunn, and the drift‐current theory as developed by Chapman as a natural consequence of the conditions necessary to the diamagnetic theory. Regardless of the spontaneous merits of these theories, much information concerning their respective probabilities should be derivable from the study of radio‐wave reflections from the ionosphere.

The atmospheric‐dynamo theory ascribes the magnetic variations to currents flowing in the ionosphere induced by the tidal motions of the air. Gunn2 has questioned the possibility of such currents because in the region of long free‐paths the average motion of the ions will be in the direction at right‐angles to the magnetic and electric fields present rather than in the direction of the induced electromotive‐force. This objection is in part unwarranted because in middle and high latitudes the ions, carried by the moving air‐masses, will have their motions diverted by the Earth's magnetic field exactly as if the induced electromotive‐forces, to which they presumably cannot respond, were acting upon them. However, in equatorial regions where the vertical component of the Earth's magnetic field is practically zero, this condition does not exist and the current‐systems cannot close in the regions of long free‐paths. An accumulation of charge would result, positive to the west and negative to the east of the noon meridian, and, in spite of the electrostatic field thus set up, no current would flow unless the mean free‐path of the ions is short as compared with the radii of curvature about the magnetic lines of force due to their gas‐kinetic velocities. From our facts and surmises concerning the ionosphere it follows that, although the diurnal‐variation currents in middle and high latitudes may have their seat in the richly ionized portion of the upper ionosphere, the closing of the current‐systems must occur much nearer the Earth's surface where the mean free‐path is short—presumably in the E‐layer.
Cheltenham Magnetic Observatory October to December, 1933
Authors: Hartnell Geo.
Published: February 2008

(Latitude 38° 44′.0 N.; longitude 76° 50′.5 or 5h 07m.4 W. of Gr.)

There were no marked disturbances recorded during October to December, 1933.
The association between relative humidity and the ratio of the number of large ions to the total number of nuclei
Authors: Wright H. L.
Published: February 2008

Theoretical reasons are advanced which support the observation, noted by O. W. Torreson, that the diurnal variation of the ratio N1/N closely resembles the diurnal variation of relative humidity. A formula is obtained which relates the ratio N1/N to the radius of nuclei.
Random fluctuations, persistence, and quasi‐persistence in geophysical and cosmical periodicities
Authors: Bartels J.
Published: February 2008

The statistical aspects of the application of harmonic analysis, introduced by A. Schuster in his famous paper on the investigation of hidden periodicities, are discussed on the basis of recent developments in the theory of probability. Between the two extreme cases of random fluctuations and persistent waves, hitherto discussed exclusively, the intermediate case of quasi‐persistence is introduced and recognized as a common phenomenon in the time‐functions of meteorology, geophysics, and cosmical physics. Statistical methods, based on the conception of the harmonic dial, are given for dealing with quasi‐persistence and its effect on tests for persistent waves, and they are generalized for the case of periodicities of other form than that of the sine‐wave. Typical examples are given illustrating various forms of random fluctuations, quasi‐persistence, and persistence, as well as questions related to harmonic analysis, such as the periodogram, non‐cyclic change, curvature‐effect, equivalent length of sequences, effective expectancy, random walk, interference, and the infective property of quasi‐persistence on adjacent periods (see summary at end of paper).
Aurora of January 27, 1935, at Alexandria Bay, New York
Authors: Manning Douglas F.
Published: February 2008

As the aurora has been a rather rare occurrence for several months, I thought the following report might be of interest.

Between 19h and 20h 30m January 27, a quite brilliant and active aurora was observed at Alexandria Bay, New York (latitude 44° 20′ north, longitude 75° 55′ west) beginning promptly at 19h. It started as a pale green arch, the lower segment of which was about 20° exactly over the northern horizon, and could be designated as HA (2) according to the Photographic Atlas of Auroral Forms, published by the International Union of Geodesy and Geophysics. It gradually became brighter and higher and was soon accompanied with streamers of greenish hue, RA (25–26 of the Atlas). At this time patches of intense green light would develop with tinges of pink and yellow, such bundles of rays seeming to turn and move rapidly about and to the west. All this time this aurora was working higher towards the zenith but never higher than 35° to 40°. At one time a patch of whitish light was seen in the east near the zenith but this soon died away. After considerable activity with constantly changing rays kindling and dying out with at times intense colors of greenish hue, the aurora gradually spread all over the northern sky and then finally died out entirely. At 20h 30m there was only a faint glow. At the time of observation the sky was absolutely clear with light northwest winds and the temperature — 18°F.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory January, February, and March, 1935
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

The storm of January 27 began with a sudden commencement in which the horizontal intensity increased by 20 gammas. No solar activity of an unusual nature was recorded during or immediately preceding either of these storms.