bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic declination and latitude observations in the Bermudas
Authors: Cole J. F.
Published: February 2008

At the wish of Prof. E. L. Mark, Director of the Bermuda Biological Station, the writer spent the three weeks from March 27 to April 17, 1905, in Bermuda for the purpose of making first, a general investigation of the distribution of the magnetic declination in the Islands, and second, a determination of the latitude at some station. Climatic conditions at that time of the year were very favorable for completion of the necessary work in a short space of time. Thanks are due to Mr. Goodwin Gosling, of Bermuda, for providing a horse and buggy and also charts of the Islands. Most of the instruments were the property of the writer.
The earliest values of the magnetic declination
Authors: Bauer L. A.
Published: February 2008

The exhaustive and painstaking researches of the late Timoteo Bertelli, on the discovery of the fact that a magnetic needle does not point precisely north and south, but makes an angle with the true meridian, appeared to have settled the question as to whom chief credit was to be given, viz., to Christopher Columbus.

While accepting Bertelli's conclusion, the noted meteorologist and bibliographer, Gustav Hellmann, reached the opinion in his “Die Anfänge der Magnetischen Beobachtungen, Berlin, 1897”1 from a study of early sun‐dials, that “it was the construction of sun‐dials which first brought those on land to a true perception of the declination of the magnetic needle from the astronomical meridian and not the discovery of Columbus, of which nothing appeared in print.”
The New Zi‐ka‐wei Magnetic Observatory
Authors: de Moidrey J.
Published: February 2008

Les tramways électriques de Shanghai ont commencé à fonctionner depuis quelques jours. J'ai éteint ce matin les lampes de notre vieil enregistreur; elles avaient été allumées par le F. M. Dechevrens, en février 1877: 31 ans.

Nous allous dans quelques jours nous transporter à la nouvelle station dont les constructions sont presque achevées, et nous y reprendrons les observations le plus tôt que nous pourrons.
Results of recent magnetic observations in Mexico (1906–'08)
Authors: Valle Felipe
Published: February 2008

I take pleasure in communicating to this Journal an abstract of the magnetic observations recently made in Mexico under the direction of this Observatory.1 The designations of the respective observers used in the tables are:

M. M. A.—Manuel Moreno y Anda.

A. D. C—Abel Diaz Cobarrubias.

V. G.— Valentin Gama.
The physical theory of the Earth's magnetic and electric phenomena: 5. On the formation of the Earth's magnetic field
Authors: Bauer L. A.
Published: February 2008

54. The opinion was expressed in §2 that it was doubtful whether “we should ever be able to solve the problem as to the origin of terrestrial magnetism until we had found out what, causes the Earth's magnetism to vary.” A general study of the time and spasmodic variations of the Earth's magnetic condition led to a relation which was put in the following tentative form (l. c.): “Alterations in the Earth's magnetic condition, whatever their nature or origin may be, appear to be distributed over the globe according to a law profoundly dependent upon that governing the distribution of the Earth's own primary magnetic forces.” The exemplification and deduction of the consequences of this law are reserved for a future number.

It seems advantageous at this stage to take up a study of possible disturbing forces which, operating on a simple, uniform magnetization of the Earth about some diameter, such as that of the axis of rotation, could change it into the heterogeneous or complex magnetic system of forces actually observed. The method of the Gaussian analysis results in a cumbersome mathematical expression embracing a large number of terms. Though it has been in use for three‐quarters of a century, and has counted among its devotees most eminent investigators, the precise physical interpretation of the harmonic terms beyond that of the first still awaits solution. Indeed, the general opinion has been that the departure from uniform magnetization is to be ascribed primarily to the heterogeneous structure and formation of the Earth's crust. A favorite theory referred the chief cause of irregularities in the distribution of the Earth's magnetic forces over its surface to the relative distribution of land and water.
The physical theory of the Earth's magnetic and electric phenomena, no. VI: On the origin of the Earth's magnetic field
Authors: Bauer L. A.
Published: February 2008

62. The results obtained in the previous number, if not considered as definitely proving that a part at least of the Earth's magnetism is in some manner dependent upon the Earth's rotation, gave strong indications that such, indeed, is the case. Perhaps the result of greatest importance was that the forces which cause the Earth's magnetization to depart from that of a uniformly magnetized sphere follow, as a first approximation, certain definite and comparatively simple laws. When, for example, the Earth's magnetic moment was obtained separately for each parallel of latitude from 60 N. to 60 S., on the assumption that the measured magnetic forces are those resulting from a uniformly magnetized sphere, a systematic increase in the value was found in both hemispheres with approach towards the equator. This fact, as will be seen, furnishes a crucial test of the sufficiency of the theories already propounded to account for the origin of the Earth's magnetism.
Radler de Aquino's newest navigation altitude and azimuth tables
Authors: Ault J. P.
Published: February 2008

The fact that this latest book by Lieut. Radler de Aquino, of the Brazilian Navy, offers ready solutions, without the use of logarithms, for nearly all the problems of navigation, that the method used is general for all solutions, and that it contains in compact form all the necessary tables, should make it popular, and especially so to the navigator who dislikes to use logarithms.

After the tables are once thoroughly understood and the various precepts remembered, they can be used very readily, being particularly valuable for star sights, when two or more stars are observed simultaneously, for star identification, and for obtaining corrections for variations in data.
Results of magnetic observations made by the United States Coast and Geodetic Survey at the time of the solar eclipse of October 10, 1912
Authors: Tittmann O. H.
Published: February 2008

These results were obtained in response to a circular letter received from the Director of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington requesting cooperation in magnetic and allied observations at the time of the solar eclipse of October 10, 1912.

The magnetic observers in charge of the observatories were directed to exercise especial care to have the magnetographs in good working order on October 10, and for several days before and after that date.
The magnetic character of the year 1912
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1912 has been drawn up in the same manner as for the preceding years. Forty‐three observatories contributed to the quarterly reviews; all of them sent complete data. According to a request from the Executive Bureau of the Commission on Terrestrial Magnetism of the International Meteorological Committee, the days, which seem especially suited to a reproduction, have been indicated on the quarterly publications. Table II of the annual review, containing the mean character,of each day and of each month, the list of “calm days” and the days recommended for reproduction, are reprinted here.
The measurement of atmospheric conductivity, together with certain remarks on the theory of atmospheric radioactive measurements
Authors: Swann W. F. G.
Published: February 2008

Perhaps the best‐known method of measuring the conductivity of air is that devised by Gerdien, in which air is drawn through a cylindrical condenser, and the rate of movement of the leaf of an electroscope connected to the inner cylinder is noted. Another method has, however, been developed at Potsdam, in which the conductivity is deduced by noting the rate of alteration of potential of a long charged wire, surrounded by an earthed netting. The fact that this method presents the very valuable feature of being readily applicable to automatic registration renders it desirable to form as close a scrutiny of it as possible from a theoretical point of view, in order to be able to predict more certainly its exact limitations. This is especially the case in view of the fact that the values of the conductivity as measured by this method at Potsdam are abnormally low, being only about 50 per cent of that found at other places.
The free and forced vibrations of a suspended magnet: Concluded
Authors: Reid Harry Fielding
Published: February 2008

Vertical Disturbance. In 1860 Melde1 showed that a stretched string could be set in strong transverse vibration by a longitudinal movement of its end with a period half that of the transverse vibration. Lord Rayleigh2 pointed out that this principle applied to many kinds of vibrations, and especially that a pendulum could be made to vibrate through a large arc by a properly‐timed vertical movement of the support. The period of the disturbance is half that of the vibration.
British Association meetings for the discussion of geophysical subjects
Authors: Chapman S.
Published: February 2008

The various branches of science which deal with the physical, metrical and dynamical properties of the Earth are in many ways closely inter‐related, both on their theoretical and observational sides. It has too long been the case, however, that workers in each branch have pursued their investigations without being able to maintain adequate touch with what is being done in the other sections of the science. This has largely been due to the lack of a common meeting‐ground at which investigators, and others who take interest in the subject, may read and discuss papers and reports, and in other ways contribute to the common advancement of our knowledge of the Earth. In order to remove this drawback the British Association for the Advancement of Science has recently appointed a Committee to arrange meetings in the coming year for the discussion of geophysical subjects, and also to co‐operate with existing committees in making recommendations for the promotion of the study of such subjects in the British Empire.
The magnetic storm of August 11–12, 1919, as observed at the Apia Magnetic Observatory, Samoa
Authors: Angenheister G.
Published: February 2008

[From a blue print transmitted to the Journal by Dr. G. Angenheister, the observer‐in‐charge, the following information has been obtained respecting the chief characteristics of the severe magnetic storm of August 11–12—the severest registered at the Apia Magnetic Observatory since the one of September 26, 1909. All the times given refer to Greenwich civil mean time; they are to be regarded as approximate, as also the absolute value of the magnetic elements; the scalings were made by the Department of Terrestrial Magnetism.]

Declination (D). No large perturbations occurred and there was no marked “sudden commencement” near 7h August 11. At about 7h 58m, there is a sharp rise of a few minutes, signifying diminishing east declination (D); the value of D at this point is about 10° 14′ E. A minimum D of about 10° 02′ E is reached at about 9h 53m August 11. The total range in D for August 11–12 is thus about 12′.
Concerning procedure at magnetic observatories
Authors: Chree Charles
Published: February 2008

From facts which have come to my knowledge since writing the note which appeared under the above title in the December, 1919, number, it seems to me desirable to amplify the statement made on page 158 that the use of 60‐minute mean ordinates tends “to give too small amplitudes for the Fourier waves, especially those of shortest period.” This is sufficiently obvious to the mathematician, when the question is presented as a mathematical problem; but it is apt not to suggest itself—I speak from personal experience—to one habituated to the use of the ordinary formulae, and concerned at the moment only with the physical aspect of the case.

Fortunately it is easy to make the necessary allowance. The mathematical aspects are discussed in the British Association Report for 1883, page 98, as part of a report on harmonic analysis drawn up by the late Sir George Darwin. All that is necessary is to apply to the amplitude coefficients, calculated from the ordinary formulae, the following correcting factors (1 c. page 98):

24‐hour wave, 1.00286; 12‐hour wave, 1.01152; 8‐hour wave, 1.02617; 6‐hour wave, 1.04720; 4‐hour wave, 1.11072; 3‐hour wave, 1.20920

The phase angles are unaffected.
Magnetic storm of March 22–23, 1920
Authors: Hazard D. L.
Published: February 2008

A comparison of the records of the magnetic observatories of the United States Coast and Geodetic Survey shows that this storm, like the one of August 11–12, 1919, had the same general characteristics at all of the observatories, but had little correspondence in detail beyond the abrupt beginning. Because of the rapid motion and wide range of the disturbance, portions of some of the records were lost or rendered unintelligible; at Cheltenham, the decrease in H (horizontal intensity) was so great as to carry the magnet of the Eschenhagen variometer beyond the point of stable equilibrium. At Sitka, the observer, at the time of changing paper, noticed that a severe storm was in progress and widened the slit of the lantern so as to strengthen the photographic record. Greenwich mean civil time is used throughout this article.
Magnetic observations at Mauritius, May 28–30, 1919
Authors: Walter A.
Published: February 2008

In accordance with Dr. Bauer's circular letter of February 19, 1919, there are submitted the results of magnetic and meteorological observations made at the Royal Alfred Observatory, Mauritius, in connection with the solar eclipse of May 29, 1919, which it is hoped will be found serviceable. [Five‐minute values of D (declination), H (horizontal intensity), and Z (vertical intensity), from 10h to 16h 30m, G. M. T., were supplied for May 27, 28, 29, 30, and 31. Tables 1, 2, 3, and 4 were derived from these data. Geographic coordinates: Latitude 20°05′.6SN.; longitude, 57° 33′.2or 3h 50m.2E. —Ed.]
Records of earthquakes at Watheroo Magnetic Observatory
Authors: Kidson Edward
Published: February 2008

The following particulars are given of earthquakes recorded on the magnetograms of the Watheroo Observatory, Western Australia. All times refer to 120th east meridian standard time. The geographic coordinates are: latitude 30° 18′ S; longitude, 115° 53′ E. See previous issues for records of earthquakes already reported upon.
Some results of recent earth‐current observations and relations with solar activity, terrestrial magnetism, and atmospheric electricity
Authors: Bauer Louis A.
Published: February 2008

1. Renewed interest was aroused by the remarkable earth‐current disturbances of May 14 to May 20, 1921, and, as will be recalled, there were also at the time brilliant displays of polar lights, severe magnetic storms, and manifestations of pronounced solar activity. These disturbances and accompanying phenomena occurred over the entire Earth. Northern lights were observed in lower northerly latitudes than usual, and southern lights were seen as far north in the Southern Hemisphere as Apia, Samoa—a very unusual occurrence. In certain respects the disturbances, during the period mentioned, were similar to those which occurred August 29 to September 4, 1859.
Magnetic and atmospheric‐electric disturbances and auroral displays, Western Australia, January 1923
Authors: Wait G. R.
Published: February 2008

The records obtained at the Watheroo Magnetic Observatory show magnetic and atmospheric‐electric disturbances concurrently with auroral displays visible in Western Australia during January 1923.

The records for all magnetic elements show very irregular movements between 19h and 20h January 20, which continue until approximately 15h on January 21, when there is a gradual recovery from these irregular movements, which continues for several days.
Correlations between solar activity and atmospheric electricity
Authors: Bauer Louis A.
Published: February 2008

The question is revived whether atmospheric electricity is in any way dependent upon solar activity. The present investigation is based chiefly upon the accumulated data for electrically‐quiet days pertaining to the atmospheric potential‐gradient and its diurnal and annual variations. It is found that during the past two sun‐spot cycles (1901–1923), the atmospheric potential‐gradient and the amplitudes of the diurnal variation and of the annual variation generally increased with increased sun‐spot frequency; the increase in the particular electric element considered is about 20 to 35 per cent, on the average, for a change of 100 in the sun‐spot number. The correlation coefficient, on the average, is about 0.75.

If reliance can be placed on older series of atmospheric‐electric observations, made prior to 1901, then there are indications that during two periods, centering about 1855 and 1889, the reversed relationship applied, namely, that increased atmospheric potential‐gradient and increased amplitudes of diurnal and annual variation were associated with decreased sun‐spot frequency. The forthcoming sun‐spot cycle will afford opportunity to examine into this matter more thoroughly.

An interesting correlation is exhibited by the atmospheric‐electric and magnetic data for 1893, which unite in showing a decrease in the electric and in the magnetic activity at the time of maximum sun‐spot frequency. There is thus an indication that the usual measures of solar activity are not always an adequate measure of such solar radiations and emanations as may affect the electricity of the atmosphere and the magnetic field of the Earth.

The hope is expressed that the results of the present investigation will contribute towards the multiplication of widely distributed atmospheric‐electric stations where all possible care will be taken to ensure continuity of strictly comparable data for a sun‐spot cycle, and longer.
The Kursk magnetic anomaly
Authors: Lasareff P.
Published: February 2008

In a previous note I gave the results of investigations carried out during 1921–1923, and in the present paper I propose to give the details of work executed in the period of 1923–1925. I have already indicated the dimensions and direction of the anomalous zone in the Kursk Government, Figure 1 is a general map of the anomalies of magnetism and gravity; it also shows the direction of the anomaly and the relative value of the vertical intensity Z, which has two maxima, one in the Stschigry district and the other in the Stary Oscol district.

The details of the variation of the vertical intensity along the anomaly are given in Fig. 2.
Principal magnetic storms recorded at the Huancayo Magnetic Observatory, July to September, 1926
Authors: Goddard Richard H.
Published: February 2008

(Lat. 12° 02′.7S.; long. 75° 20′.4 W. or 5h 01m W. of Gr.)

There were no magnetic storms during July or August.
Principal magnetic storms recorded at the Sitka Magnetic Observatory, October to December, 1927
Authors: Ulrich F. P.
Published: February 2008

October 9–11 1927.—This storm is peculiar because of the short rapid oscillations of the elements on October 10 at 13h to 23h. After 15h the mean values of the oscillations are about the mean values of the normal curves. The oscillations are so rapid that the curves are mostly spots up to 21h, but, each curve being separated, the path can be accurately determined.

October 12 1927—The motion of the curves is so rapid that in places the curves consist of spots only from 11h to 17h. At that time the trace was changed and the light increased. From 17h to 22h the curves consist of fairly large rapid oscillations.
Charles Chree
Authors: Chapman S.
Published: February 2008

Charles Chree, for many years one of the most eminent and indefatigable workers on terrestrial magnetism, died on August 12, 1928, after an illness, patiently and bravely borne, lasting for several months.

He was the second son of the Rev. Charles Chree, D.D., minister of Lintrathen in Forfarshire, a country parish a few miles from Kirriemuir—Barrie's “Thrums”; he was born on May 5, 1860. He was educated at the Grammar School, Old Aberdeen, and at the Universities of Aberdeen, where he gained distinction in classics as well as in mathematics and physics, and Cambridge. At the latter he was sixth wrangler in 1883, and also took a first‐class in the Natural Science Tripos, Part 2. In 1885, he was elected to a fellowship, extended in 1890 as a research fellowship, at King's College, where he had been a mathematical scholar. He worked in the Cavendish Laboratory, and wrote many papers, to which numerous references may be found in Love's treatise, on the mathematical theory of elasticity.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

The year covered by this summary (July 1, 1929, to June 30, 1930) has been a momentous one in the history of the Department because of the disaster to the Carnegie at Apia, November 29, 1929, in which Captain James Percy Ault, chief of the section of ocean work and commander and scientific leader of the Carnegie, lost his life. The scientific work of Captain Ault finds its chief expression in the achievements of the Carnegie, of which he had been the commander during the last fifteen years of her activity. To him is due in large part the continued success of the later cruises, and the unique series of observational records obtained during Cruise VII will henceforth serve as a basis for practical and theoretical studies in geophysics over the oceans. The general esteem in which he was held and the great loss not only to our own sciences of terrestrial magnetism and electricity but also to oceanography occasioned by his death is evidenced by the resolutions of condolence adopted by scientific organizations everywhere and by innumerable letters from investigators and national organizations interested in geophysics both in America and abroad.
Correction‐factors and corrected daily means of the solar indices as given in the International Astronomical Bulletins
Authors: Brown Howell C.
Published: February 2008

An attempt was made to use the solar character‐numbers, as given in the International Astronomical Union Bulletins, for correlation with radio‐fading. The daily reports from the cooperating observatories varied so greatly that it was considered necessary to make a corrected average.

The various stations were compared by groups, in three‐month periods when possible, but at times it was necessary to make use of a six‐month period. From these comparisons a multiplying‐factor was prepared and the daily reports thus corrected. The corrected figures were then averaged to obtain a new daily mean.

Some general comments on the use of standard plates are included.
Provisional sunspot‐numbers for December 1930 to February 1931
Authors: Brunner W.
Published: February 2008

(Dependent alone on observations at Zürich Observatory and its station at Arosa)
Magnetic secular variation for epoch 1930
Authors: Ennis C. C.
Published: February 2008

In the JOURNAL for September 1931 appeared a paper by J. Bartels on geophysical stereograms. It was the privilege of the writer to assist the computations incident to the construction of the various stereograms accompanying that paper, and it seems a worth‐while contribution in the field of magnetical investigation to make available the data employed in the construction of stereogram 8 which shows the secular variation of the magnetic field‐vector at the intersections of the meridians 0°, 20°, 40°, etc, with the circles of latitude 60°N, 40°N, . .40°S.

As the resulting salient features of the secular variation were pointed out by Bartels, it is intended herein to give only the data upon which the stereogram depends. These are embodied in Table 1.
Sitka Magnetic Observatory April to September, 1931
Authors: Ulrich Franklin P.
Published: February 2008

(Latitude 57° 03′.0 N.; longitude, 135° 20′.1 or 9h 0lm.3 W. of Gr.)

There were no major storms during the quarter April to June.
Terrestrial‐magnetic activity and its relations to solar phenomena
Authors: Bartels J.
Published: February 2008

A homogeneous series of monthly means of terrestrial‐magnetic activity for the years 1872 to 1930 is derived and extended backward, in annual means, to 1835. The annual variation of magnetic activity and of the relative sunspot‐numbers is discussed by means of new tests for periods. Only the semi‐annual wave in magnetic activity is recognized as physically significant. Its maxima prefer the times when the Sun is in the celestial equator, and not, as has been suggested, the times when the Sun's axis is most inclined towards the ecliptic. This view is supported by tests using the harmonic dial and the probable‐error circle, and several independent considerations.

The close relations between sunspot‐numbers and terrestrial‐magnetic activity in the annual and monthly means are discussed. Some general statistical aspects are given for the treatment of the correlation between such series with after‐effects, for which both solar activity and terrestrial‐magnetic activity are typical. The homogeneity of the whole available series for relative sunspot‐numbers and for areas of sunspots and faculae is tested; some inhomogeneities are found, apart from a general lag of terrestrial‐magnetic activity that has occurred in some sunspot‐cycles. A break in the homogeneity of the international magnetic character‐figures in recent years is discovered.

The individual 27‐day recurrences in terrestrial‐magnetic activity during 1906–31, and their relations to solar activity are discussed with the help of a graphical day‐by‐day record. They indicate the existence of persistent active areas on the Sun's surface, called M‐regions, which, in many cases, cannot be coordinated to such solar phenomena as are observable by direct astrophysical methods. This holds in particular for the new solar indices which are available for the years 1928–30, and which are found so closely correlated to sunspot‐numbers, that they fail to improve the correlation between solar activity and terrestrial‐magnetic activity. Observations of terrestrial‐magnetic activity yield therefore not only information about geophysical influences of such solar phenomena that may be traced in astrophysical observations, but supplement these direct observations themselves.
Cheltenham Magnetic Observatory October to December 1931
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 large magnetic disturbances during the quarter. A mild storm began at about 5h, G. M. T., October 29, and continued to about 22h, October 30; the ranges were 57.7′, 196γ, and 141γ in declination, horizontal intensity, and vertical intensity, respectively.
Provisional sunspot‐numbers for March to May 1932
Authors: Brunner W.
Published: February 2008

(Dependent alone on observations at Zürich Observatory and its station at Arosa)
Cheltenham Magnetic Observatory January to March 1932
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 magnetic storms recorded during the first quarter of 1932.
The development of the magnetic survey of Canada
Authors: Jackson W. E. W.
Published: February 2008

The untimely death of Dr. Bauer cast a gloom over the whole world of magnetism. His enthusiasm was contagious and had spread throughout all lands. We in Canada were early affected by his influence and are now happy to join in a “Memorial” fitting his achievements. He will always live in the minds and hearts of all who were privileged to have known him.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, October, November, and December, 1932
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

The only magnetic storm during the fourth quarter of 1932 in which the total range in H exceeded 100γ was on October 20 and 21. It was probably caused by the small group No. 4377 which crossed the central meridian 3° north of the center of the disc on October 20, 4h, G.M.T. Group No. 4379, which crossed the central mendian on October 24.3, G.M.T., was much larger than No. 4377, but was less active, as judged by the hydrogen spectroheliograms. The magnetic storm began October 20 at about 10h and ended about 12h the following day; the range in horizontal intensity was 128γ.
A new theory of magnetic storms
Authors: Chapman S. , Ferraro V. C. A.
Published: February 2008

10.1—The distortion of the front surface of the stream produced by the magnetic field as the stream advances towards the Earth has been described briefly in §§6.6 and 7.7; as was there mentioned, we have not discussed in detail the shape of the hollow formed, or the subsequent phenomena occurring therein. We defer this consideration until we have a clearer understanding of the mode in which the ions near the surface of the stream are able to advance into the Earth's field. But certain general features can be deduced, as has been pointed out already in §1.8; the hollow gradually shrinks at a diminishing rate, but we cannot say at present whether it ultimately closes in upon the earth. The preceding analysis suggests that once the velocity of the particles is diminished to, say, 1/10 of its initial value (108 cm/sec), the rate at which the hollow closes up becomes slow.
Apia Observatory October to December, 1934
Authors: Wadsworth J.
Published: February 2008

November 7—A slight disturbance began at 4h 50m, G.M.T., with a gradual increase of 6γ in H. It reached a maximum increase of 32γ at 8h 45m and afterwards fell by 24γ between then and 9h 10m. The corresponding movements in Z were much smaller, namely, increases of 2γ and 5γ and then a fall of 6γ.

December 1—A sudden increase of 22γ occurred in H at 4h 57m, G.M.T., and an increase of 5γ in Z.

December 11—A sudden increase of 15γ took place at 10h 34m, G.M.T., with an increase in Z of 3γ

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).
Concerning the magnetic numerical character‐numbers
Authors: Egedal J.
Published: February 2008

In a communication presented to the Assembly of the Association of Terrestrial Magnetism and Electricity held at Lisbon September 19331 the author gave the results of a comparison of numerical character‐numbers with international character‐numbers. It was shown that the numerical character‐number corresponding to the international character‐number 0.2 for the magnetic observatory at Rude Skov was about 120 in the winter (December) and about 240 in the summer (June).

In the present note the magnitude of the numerical character‐numbers for magnetically quiet days for observatories at different latitudes is examined. The numerical character‐numbers for the five international quiet days of June and of December for the years 1932 and 1933 are considered.
The hundredth anniversary of the Sverdlovsk Magnetic Observatory
Authors: Abels R. G.
Published: February 2008

Introduction—On January 1, 1836, in Sverdlovsk (formerly Ekaterinburg) regular meteorological and, at the end of that same year, magnetic observations were initiated. Accordingly we celebrated the hundredth anniversary of the Sverdlovsk Magneto‐Meteorological Observatory on June 25, 1936. The Anniversary Symposium of the Observatory published at that time contains the following articles dealing with the magnetic activities of the Observatory during the past 100 years.

G. F. Abels, Magnetic observations in Sverdlovsk (formerly Ekaterinburg).
Tucson Magnetic Observatory July to September, 1936
Authors: Joyce J. Wallace
Published: February 2008

(Latitude 32° 14′.8 N., longitude 110° 50′.1 or 7h 23m.3 W. of Gr.)

July 5–8—A moderate disturbance was characterized by an abrupt commencement in all three elements at 02h.5 GMT, July 5. H increased 29 gammas in six minutes. In general, the storm consisted of a series of long bays with a three‐hour interval of short‐period activity starting at 9h, July 6. The storm ended at about 3h, July 8. Total ranges: Horizontal intensity, 90 gammas; vertical intensity, 59 gammas; declination, 12′.
Apia Observatory April to June, 1937
Authors: Wadsworth J.
Published: February 2008

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h 27m.1 W. of Gr.)

April 12—A disturbance commenced suddenly at 08h 50m GMT, April 12, with an instantaneous increase in H equal to 12 gammas. The maximum value of H was attained between 11h and 12h and the minimum at 18h 25m. The range in H was 46 gammas.
Auroras of September 4 and 10, 1937
Authors: Brooks Charles F.
Published: February 2008

Douglas F. Manning of Alexandria Bay, New York, reported: “We had quite an active display of the aurora last night, September 4, 1937, around 9 p.m., Eastern Standard Time. A low greenish glow with sharply defined rays.” A later phase was observed at Lynn, Massachusetts, by Mrs. Anna P. Ricker, who, in a letter dated September 10, 1937, makes the following statement: “I was awakened about 3 a.m., September 5, 1937, and went to my window and saw these two great balls of fire about three feet in circumference to the naked eye and very close together; from each one several rays of light shot upwards, and these appeared three times in succession and from then on great waves of light at short intervals in a circular motion. These waves were about three or four feet wide and twice as long and in perfect dimension.
Natural residual magnetism of eruptive rocks
Authors: Koenigsberger J. G.
Published: February 2008

PART I—General

The study of the magnetic behavior of rocks under the influence of the Earth's magnetic field and of time, and the study of the history of terrestrial magnetism by aid of the rocks and minerals is facilitated by a knowledge of some new facts connected with physics, physical chemistry, mineralogy, and petrography. As the literature is scattered through many periodicals in various languages, the facts, which are not generally known, are summarized here. Some of these appear of interest in connection with the general theory of ferromagnetism.
Apia Observatory, January to March 1938
Authors: Wadsworth J.
Published: February 2008

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h 27m.1 W. of Gr.)

January 16‐18—A sudden commencement occurred at 00h 44m GMT, January 16, when H increased 56 gammas. After this the traces were only slightly disturbed until 22h 37m when rapid oscillations in H and Z were recorded. H fell gradually through a range of 281 gammas until 18h 52m, January 17, when it returned to normal values though it continued to show slight disturbances. Ranges: Z, 32 gammas; D, 9′.
Scattering of radio waves by the F‐region of the ionosphere
Authors: Booker H. G. , Wells H. W.
Published: February 2008

Records are reproduced showing diffuse echoes from the F‐region of the ionosphere received continuously at night in equatorial regions over a wide range of wave‐frequency. Tney are interpreted as due to Rayleigh scattering by spatial irregularities in the distribution of electron‐density at or above a definite level in the F‐region. Because of the highly dispersive nature of the ionosphere, there is no marked dependence of Rayleigh scattering upon wave‐frequency such as there is for a non‐dispersive medium. According to this interpretation, variation of the maximum wave‐frequency to which diffuse echoes can be followed has nothing to do with variation of the maximum electron‐density of an ionospheric region, but merely indicates variation in the size of irregularities in electron‐density. Scattering of this type may have some bearing upon the phenomenon of persistence of E‐region echoes to wave‐frequencies greater than the critical penetration‐frequency of the E‐region.
Cheltenham Magnetic Observatory October to December, 1938
Authors: Ludy Albert K.
Published: February 2008

October 7–9—A storm occurred between 06h 15m GMT, October 7, and 02 h October 9. The oscillations were irregular and the larger ranges took place between 22 h, October 7, and 08h, October 8. Ranges: D, 47′; H, 225 gammas; Z, 238 gammas.

October 23–28—After a period of slight disturbance beginning October 23, there gradually developed a mild storm which lasted several days until October 28. Although the ranges were not great there was continmd activity during this time.
Cheltenham Magnetic Observatory July to September, 1939
Authors: Ludy Albert K.
Published: February 2008

July 3–4—A sudden commencement occurred at 00 h 39 m GMT, July 3, and was followed by a period of moderate disturbance lasting until 06 h, July 4. Ranges: D, 28′; H, 298 gammas; Z, 150 gammas.

July 4–6—After an interval of about eight hours of quiet conditions a storm began at 14 h 07 m GMT, July 4. All three elements were active until 05 h, July 6. Ranges: D, 61′; H, 424 gammas; Z, 426 gammas.
Apia Observatory, April to September 1939
Authors: Sapsford H. Bruce
Published: February 2008

April 16–17—A sharp rise of 22 gammas in horizontal intensity between 21h 29m and 21h 35m GMT, April 16, was followed at 01h 58m April 17, by a further sudden increase of 45 gammas. The maximum of the disturbance occurred at 02h 04m and after that time the horizontal intensity decreased 295 gammas rapidly to a minimum at 08h 39m. Vertical intensity was correspondingly affected but owing to the diurnal variation the maximum during the disturbance was not recorded until 15h 47m, April 17. Declination showed slight variations during the period of the storm.
Tucson Magnetic Observatory October to December, 1939
Authors: Hershberger John
Published: February 2008

October 3–4—A storm began very indefinitely about 08h GMT, October 3, but did not become severe until about 01h, October 4, although in the meantime average H had decreased considerably. Between 01h and 05h, H executed a fairly deep bay, while the other elements were moderately disturbed. Except for a continued low H, the storm ended at about 05h.
Auroras, radio field‐strengths, and recent solar activity
Authors: Stetson Harlan T.
Published: February 2008

Of the many suspected relationships between observable terrestrial phenomena and solar activity, as marked by sunspots, those longest recognized are the variations in the characteristics of the Earth's magnetic field and the occurrences of auroras. The advent of radio communication in recent years has opened up a new field for the investigation of conditions of ionization in the Earth's upper atmosphere and affords a new source of observational data for the study of solar‐terrestrial relationships. The simultaneous occurrence of radio fade‐outs, solar eruptions, and violent changes in the Earth's magnetic field have received wide attention. The more general changes in radio transmission with the occurrences of auroras, and geomagnetic fluctuations accompanying increased sunspottedness are of a more gradual nature and probably follow in a somewhat different category from phenomena of the eruptive fade‐out.
Huancayo Magnetic Observatory October to December, 1939
Authors: Wells H. W.
Published: February 2008

October 1–2—Abnormally large diurnal bays in H occurred on both October 1 and 2 with respective ranges of 326 and 314 gammas.

October 3–4—A magnetic storm featuring large fluctuations in H began at 12h GMT, October 3, and ended at 05h, October 4. Ranges: D, 13′.7; H, 465 gammas; Z, 67 gammas.
A significance‐test for ellipticity in the harmonic dial
Authors: Mauchly John W.
Published: February 2008

(1) Introduction—The Fourier coefficients obtained from harmonic analysis of observations of periodic or quasi‐periodic phenomena may be conveniently exhibited as points in Euclidean space. As a simple illustration, the 12‐hour oscillations in barometric pressure, which have occurred at any one station on N different days, may be represented both in amplitude and in phase by N points in a plane. This device has been used by Bartels [see 1 and 3 of “References” at end of paper], Chapman (who gave it the name “harmonic dial”), and others, in studying atmospheric tides, magnetic variations, and similar phenomena. As an example, Figure 1 by Bartels is here reproduced [1].
Apia Observatory January to March, 1940
Authors: Sapsford H. Bruce
Published: February 2008

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h 27m.1 W. of Gr.)

March 23—A minor disturbance began at 06h 15m GMT, March 23 with a sudden increase in H of 21 gammas and in Z of 6 gammas. The H‐trace then fell to a minimum at 09h 22m through a range of 81 gammas. The corresponding range of Z was 16 gammas. D was only slightly affected. The trace returned to normal level shortly after 10h but small rapid oscillations continued.
Secular Change at Cheltenham, Maryland
Authors: Howe H. Herbert
Published: February 2008

It will be remembered that about 1933 a phenomenal change took place in the rate of secular change of declination at Cheltenham, Maryland. Within about a year the rate changed from an increase of 4 minutes per year to zero. This change of rate has persisted, the present rate being a few tenths of a minute per year, decreasing. (4′ per year means about 21γ per year)

Recently a larger and nearly as abrupt decrease has taken place in the rate of secular change of horizontal intensity. Determination of a rate of secular change for short periods is complicated by the annual variation, which has an amplitude of some 20γ. Plotting monthly means and drawing a smooth curve, the following were obtained as approximate rates of secular change (in gammas per year, decreasing) for the middles of consecutive years from 1933 to 1940: 54, 50, 47, 44, 41, 32, 21,3.
Watheroo Magnetic Observatory, April to June, 1941
Authors: Parkinson W. C.
Published: February 2008

April 24–25—A small magnetic disturbance began with a sudden commencement in all three elements at 07h 20m GMT, April 24. For the following 24 hours the traces were only moderately active, the most important features being: (a) A gradual decrease of H between 08h 30m and 09h 40m of 134 gammas; (b) a small rapid double oscillation shown in all three elements at 13h 30m. By 08h, April 25, the traces had regained the normal characters. A small group of sunspots was observed on both days but no activity was seen during the periods of observation.
American magnetic character‐figure, CA, three‐hour‐range indices, K, and mean K‐indices, KA, for October to December, 1942, and summary for year 1942
Authors: Johnston H. F.
Published: February 2008

Summaries of American URSI broadcasts have appeared regularly in this JOURNAL since the issue for December, 1930.

As set forth in this JOURNAL for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for October to December, 1942, are given in Table 1.
Magnetic activity at Dombås based on absolute storminess for the horizontal component
Authors: Wasserfall K. F.
Published: February 2008

Introduction—Absolute storminess, AS, means the diurnal sum of positive and negative storminess, and is one of the best expressions for magnetic activity. Since 1916 daily values for AS, for D, H, and V, have been published in our year‐books, but so far no attempt has been made to make further use of these valuable data, except that AS for D has been regularly used as the basis for our contribution to the international character‐number, C.

For various reasons it has been considered desirable to devise a new international measure for magnetic activity in addition to the character‐number, C. There is no doubt that AS would be a good basis for this new international measure except that few observatories compute data for AS. For this reason the Assembly at Washington in September 1939 decided to base the international cooperation, not on AS, but on the so‐called three‐hour‐range index K. As the work required for deriving the K‐index is much less than that connected with working out data for AS, this scheme for international cooperation seems to have been generally accepted, and—judging from results already published—there is every reason to believe that the K‐index more or less covers what is required for the new measure for magnetic activity.
Magnetic Observatory, Hermanus, October to December, 1942
Authors: Ogg A.
Published: February 2008

(Latitude 34° 25′.2 S., longitude 19° 13′.5 or 1h 16m.9 E. of Gr.)

October 2–5—A sudden‐commencement storm began at 02h 46m GMT, October 2. H increased 21 gammas in five minutes. At first the disturbances were small and were characterized by pulsations and oscillations on all traces from 08h to 19h, October 2. The intensity of the storm gradually increased until bays of K‐index 6 were formed on all traces at 20h to 21h, October 2. On October 3 at 01h and 04h, bays of K‐index 4 were formed on all traces. Disturbances continued until 01h, October 5.
Brief Compendium on the Sphere and Art of Navigating
Authors: Cortes Martin
Published: February 2008

Chapter 3—On the virtue and property of the lodestone

The lodestone according to the Cardinal Cusanus has essence, virtue, and operation. The virtue is engendered by the essence; from the essence and virtue is born the operation, so that the stone communicating its virtue to the iron for this reason causes the iron to move although between them there be a silver dish or plate or something similar. The attractive force of the lodestone causes the nature of the iron to join with it and at rest so much that although heavy and weighty it does not fall because the nature of the iron does not remain in it but joins with the nature of the stone which seems to extend whence we see that by this union it happens that it not only attracts this iron but this to another, and another to another and thus is formed a chain* as experience has shown. St. Augustine was surprised as he has written in the books of “De Civitate Dei”1 because on a plate he saw a bit of iron agitated when the lodestone was moved about under the plate.
Sitka Magnetic Observatory, October to December, 1943
Authors: Pinckney Harold W.
Published: February 2008

Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 01m.3 W. of Gr.]

October 1–4—The disturbance in progress at the end of September continued with diminishing intensity through the night of October 4.