bluuebunny/crossref_metadata_2025 huggingface dataset:
Sitka Magnetic Observatory January to March, 1935
Authors: Herschenberger John
Published: February 2008

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

March 14—This storm began about 6h, with a gradual increase of about 35′ in east declination, accompanied by small increases in the other elements, and followed by similar decreases in all the elements. About 8h.5 the fluctuations became violent, characterized by small, short‐period oscillations superimposed on slow, large movements. The severest part of the storm ended about 18h, but the record continued moderately stormy for about 24 hours longer. A lesser disturbance had occurred about 20 hours before the beginning of the storm, lasting for several hours. The ranges were: Declination, 99′; horizontal intensity, 786 gammas; vertical intensity, 528 gammas.
List of recent publications
Authors: Harradon H. D.
Published: February 2008

(Latitude 30° 18′.1 S., longitude, 115° 52′.6 or 7h 43m.5 E. of Gr.)

October 24, 1934—This small disturbance began with a sudden commencement at 1h 02m, G. M. T., the horizontal intensity showing a decrease of 5 gammas in two minutes. The declination changed 0′.7 westerly, while the commencement was not well marked in vertical intensity.
On the origin of the space‐charge in the atmosphere
Authors: Hansen W. W.
Published: February 2008

The purposes of the present note are to point out some of the errors in a paper by F. J. W. Whipple1 and to discuss qualitatively the space‐charge near the Earth's surface. This latter problem has been solved more exactly by W. F. G. Swann,2 E. R. von Schweidler,3 and others and the discussion to follow adds nothing essentially new to their results but is perhaps of interest because the main results are obtained by extremely simple considerations.

As Whipple says, the current at the surface of the Earth is carried entirely by positive ions. This is because the negative ions are removed by the field and none comes from the Earth to replace them. Thus a positive space‐charge exists at the surface of the Earth; and this conclusion holds irrespective of whether there is any diffusion or not. In fact if i is the air‐earth current, F is the field strength (normally positive), and w is the mobility of the positive ions, the space‐charge will be +(i/Fw); also dF/dx = +(4πi/Fw). These conclusions depend on the assumptions that all the current at the ground is carried by positive ions, that at x = 0 there is no space‐charge except that of the positive ions, that Poisson's equation holds, and that a steady state has been reached. Now Whipple's equations [either (9) or (11)] indicate that the space‐charge at the surface depends on his diffusion constant k, in fact, if k = 0 they lead to an infinite value for the space‐charge. The cause of this trouble is that Whipple's equation (2) is incorrect as is seen if we make k approach zero when it leads toi = (λ1+λ2) F which, as Wrhipple states, is incorrect at the Earth's surface. Thus Whipple's statement, “The accumulation of positive electricity near the ground on account of the interplay of conduction and diffusion is known as the electrode‐effect,” is entirely misleading. There is a positive space‐charge at the ground because the field carries the negative ions away and the conclusion is independent of whether there is or is not diffusion.
The electric current‐systems of magnetic storms
Authors: Chapman S.
Published: February 2008

1. This paper continues my discussion of the average characteristics of the field of geomagnetic disturbances or storms, given in two previous papers1 which will be referred to as 1 and 2; the irregular part of magnetic disturbance is not considered. A condensed representation of the main average features of magnetic storms is given in 1 (pp. 61–72) and 2 (pp. 242‐264), and evidence is described which supports the view that the type of the field remains fairly constant throughout a considerable range of intensity for the field as a whole.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

The activities of the Department of Terrestrial Magnetism during the report‐year July 1, 1934, to June 30, 1935, may be grouped under the following general divisions: (1) Reduction and study of accumulated observational data; (2) further development of technique and apparatus to record photographically the electrical conditions and variations in the ionosphere, and their investigation and correlation with other geophysical phenomena; (3) continued theoretical formulation and experimental investigation, in the laboratory, of basic aspects of nuclear physics and magnetism; (4) maintenance of observational program in the field to make for continuity of secular‐variation data and of recording at observatories of the Department the seasonal, diurnal, and irregular changes in the Earth's magnetic and electric fields.

As in past years, every opportunity has been taken to encourage and to cooperate with organizations everywhere engaged in geophysical research similar to that of the Department. This is in accord with the growing efforts toward world‐wide coordination sponsored by various international scientific bodies and congresses. Such coordination with studied and planned unification of methods and aims in attack is peculiarly necessary for advance in terrestrial magnetism and electricity.
Der zustand des netzes der magnetischen observatorien der U. d. S. S. R. und weitere perspektive seiner entwickelung
Authors: Rose N.
Published: February 2008

Bis 1917 zählte man auf dem Territorium der U. d. S. S. R. nur sechs magnetische Observatorien: Pavlovsk, Ekaterinburg, Sui (Irkutsk), Karsani (Tiflis), Kazan, und Odessa, wovon die letzteren zwei nur einige Jahre und zwar mit Unterbrechung arbeiteten; mit dem Beginn des Krieges 1914 hörte ihre Existenz auf.

Nach der Revolution, besonders in den letzten fünf Jahren, beginnt eine rasche Entwickelung des Observatoriumnetzes und zur jetzigen Zeit zählen wir dreizehn funktionierende Observatorien und ausserdem fünf im Zustande der Uebertragung oder der Reorganisation. Beifolgende Tabelle gibt erschöpfende Auskunft über die Lage der Observatorien und die Dauer ihrer Arbeit.
The problem of Dirichlet for an ellipsoid
Authors: Sokolnikoff I. S. , Sokolnikoff E. S.
Published: February 2008

(1) Introduction—In a group of important problems in potential theory it is required to determine a harmonic function which takes on preassigned continuous values on the boundaries of some region R. Under the proper limitations on the geometrical characteristics of the region R, it is known that the solution of the problem of Dirichlet exists and is unique, but the actual task of determining such a function often presents enormous analytical difficulties even for relatively simple geometrical configurations.

An important type of Dirichlet's problem appears in a number of investigations in electrodynamics and geophysics, where the boundaries of the region are conductors and the boundary‐values assumed by the harmonic functions are constants. Recently C. M. Rigby1 determined the electrical field produced by a distribution of charge in equilibrium on a conducting sphere lying midway between two parallel conducting planes at zero‐potential. The present paper treats of a more general problem in which the sphere is replaced by either an oblate or prolate ellipsoid of revolution, and thus enables one to calculate the field due to a charged circular disc and thin rod lying between the infinite parallel earthed planes.
Coulomb wave‐functions
Authors: Yost F. L. , Wheeler John A. , Breit G.
Published: February 2008

It is well known that magnetism is closely related to the fundamental problems of physics and that even ferromagnetism cannot be understood without a rather thorough study of atomic phenomena. Nuclear studies are throwing a new and deeper light into the constitution of matter and one may hope that through a study of nuclear phenomena a proper understanding of magnetism and electricty will be reached.

One of the ways of learning the nature of nuclear binding‐forces consists in studying the rate of reactions caused by the bombardment of nuclei with charged projectiles such as protons, deuterons, and alpha particles. In order to interpret the experimental results in terms of nuclear binding‐forces it is necessary to take into account rather accurately the effect of the Coulombian repulsion between the nucleus and the incident projectile. It is usual to treat this part of the problem by approximate methods which may at times lead to misleading results because the effect of the Coulombian repulsion is large and a small error in its estimate may lead to a considerable error in conclusions about the nuclear structure. The object of the computations presented below is to remove these uncertainties and to provide accurate values for the wave‐functions which enter the calculations.
Sitka Magnetic Observatory, July to September, 1935
Authors: Hershberger John
Published: February 2008

No storms of importance were recorded at the Sitka Magnetic Observatory during the third quarter of 1935.
Cheltenham Magnetic Observatory July to September, 1935
Authors: Ludy Albert K.
Published: February 2008

July 24–26—A mild disturbance beginning July 21 reached storm‐proportions July 24, when, at 20h 33m, there occurred an abrupt decrease in horizontal intensity of about 22 gammas followed almost immediately by an increase of about 106 gammas. At the same time the declination also changed suddenly but through a small amplitude. The disturbance continued until 4h on July 26. There were three bays in all three elements on July 25 between 5h and 9h. The ranges during the storm were: Declination 31′; horizontal intensity 154 gammas; and vertical intensity 128 gammas.
Apia Observatory July to September, 1935
Authors: Baird H. F.
Published: February 2008

July 7–10—A magnetic disturbance commenced with a sudden rise in H of 16 gammas at 21h 07m July 7, to reach a value of 35051 gammas. After oscillating about this value the trace began to descend from about 5h 00m July 8 and reached a minimum of 34910 gammas at about 10h 10m July 8. The trace then rose slowly and continued more or less disturbed until July 10.

July 19–20—The H‐trace was slightly disturbed from early July 19 until July 20.
On small local rapidly periodic magnetic fluctations
Authors: Menaw Fares
Published: February 2008

Among the interesting minor phenomena of the Earth's magnetic field are the small periodic fluctuations, having periods ranging from a few seconds to several minutes, that are occasionally observed. The late Bruno Rolf1 showed that these fluctuations are at times fairly local.

A detailed examination of these fluctuations in the three field‐components for a number of observatories spread over the affected area would show whether the fluctuations originate above or below the Earth's surface. It seems most likely that their origin is external, though if so there will in addition be a secondary internal field due to currents induced within the Earth.
Intended substitution of the practical absolute system of electrical units for the existing international system
Authors: Kennelly A. E.
Published: February 2008

(1) In accordance with the authority and responsibility placed upon it by the General Conference of Weights and Measures in 1933, the International Committee of Weights and Measures has decided that the actual substitution of the absolute system of electrical units for the international system shall take place on January 1, 1940.

(2) In collaboration with the national physical laboratories, the Committee is actively engaged in establishing the ratios between the international units and the corresponding practical absolute units.
Apia Observatory October to December, 1935
Authors: Baird H. F.
Published: February 2008

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

October 1—A slightly disturbed period commenced gradually at about 5h September 30 and continued throughout October 1.
An attempt to simplify magnetic charts
Authors: Ljungdahl Gustaf S.
Published: February 2008

Everyone who uses magnetic maps of the conventional type, where the magnetic elements are indicated by isomagnetic lines, may often meet difficulties in deciding how far the lines are sufficiently ascertained by observations, or merely obtained by interpolation, especially in incompletely surveyed or magnetically disturbed regions. The appreciation of the reliability of a map may, therefore, at times, be difficult without supplementary aid of tables containing the observational material, or of figures on the map, showing the corresponding values.

Figures are not perspicuous in the same degree as curves, and often encumber the form of the map, especially if the scale used is small in relation to the distance between the observed stations.
Maximum sensitivity‐setting of the dip‐needle
Authors: Fisher James , Service Jerry H.
Published: February 2008

Neglecting pivot‐friction and air‐resistance, the authors set up the equilibrium‐equation of moments for the common Gurley dip‐needle. By differentiation of this equation, expressions are obtained that give the best setting of the needle in any given area. In order to apply these expressions in a given area, it is necessary to know the normal inclination in the area and the approximate ratio of probable percentage increase in intensity to probable degrees increase in inclination. Graphs are given showing (1) variation of sensitivity with setting for various values of the above ratio and (2) variation of best setting with changes in the value of this ratio.
Der Tägliche Gang der Kosmischen Ultrastrahlung nach Sternzeit
Authors: Illing Wolfram
Published: February 2008

The existence of a regular diurnal variation of the cosmic‐ray ionization according to sidereal time—as postulated by A. H. Compton's theory of the extragalactic origin of the cosmic radiation—was tested by analyzing the registrations of the Cosmic‐Ray Observatory on the Hafelekar (7,000 feet above sea‐level) near Innsbruck, Austria, covering a period of three years with 21,000 hourly observations.

The triennial average‐curve giving the daily variations according to sidereal time as observed with the apparatus screened on all sides with lead (thickness 10 cm) is rather similar to Compton's theoretical curve while the observations with the apparatus unscreened from above give a different curve with two maxima at 8:30 and 19:30 sidereal time. The amplitude of the experimental curves (average of three years) is ≠0.03 per cent, somewhat less than the theoretical one (≠0.05 per cent) and much smaller than the amplitude of the daily solar‐variation (≠0.20 per cent). The observed variations according to sidereal time are of the same order of magnitude as the mean errors calculated for each point of the curve.

Although the general resemblance of the experimental and the theoretical curves seems to be an argument for the validity of Compton's theory, it must be kept in mind that an additional reduction of the experimental values on account of a slight relation between outdoor temperature and ionization might alter the appearance of the curve considerably as it was found by tentative corrections.

Final conclusions must be postponed until the correlation between outdoor temperature and observed ionization is more thoroughly investigated.
Provisional sunspot‐numbers for March to April, 1936
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, January, February, and March, 1936
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

No magnetic storm in which the horizontal intensity varied by as much as 100 gammas was recorded in the first quarter of 1936. On February 14 at 9h 24m, G.M.T., a sudden increase inH of 9 gammas was followed by feeble disturbances in the midst of which H decreased by 20 gammas in 15 or 20 minutes beginning at 15h 15m. A fade‐out in high‐frequency radio reception was reported to have occurred at exactly that time.1 On February 16 at 10h 58m a sudden increase inH of 21 gammas was followed by a very small magnetic storm.
Mount Wilson Observatory
Authors: Nicholson Seth B.
Published: February 2008

The number of sunspots depends largely on the definition of a sunspot. Each penumbral area may be considered as one spot regardless of the number of umbrae in it. According to this definition a sunspot may have several umbrae. Some observers call very small penumbral areas without an umbra “faint markings” but not spots.
Sitka Magnetic Observatory January to March, 1936
Authors: Hershberger John
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h01m.3 W. of Gr)

No storms of importance were recorded at Sitka during the first quarter of 1936.
Huancayo Magnetic Observatory January to March, 1936
Authors: Torreson O. W.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 75° 20′.4 or 5h01m.4 W. of Gr.)

January 24–25—This minor disturbance was conspicuous for its sudden commencement and for a very great decline inH directly following the commencement. At 16h 45m there was a sudden commencement in all three elements,H increasing 50 gammas in eight minutes andD andZ in the same interval increasing respectively two minutes and one gamma. At 16h 53m, immediately following the increase associated with the sudden commencement, there began a long steady decline inH which ended at 20h 38m after a decrease of 368 gammas. The value ofH at 16h 53m (approximately 29,800 gammas) was the maximum for the day and that at 20h 38m the minimum. Following the minimum,H gradually increased to normal value by 5h on January 25, there being minor fluctuations superposed on the general trend.D andZ, during the interval in question, showed numerous minor perturbations superposed on the usual diurnal trend. Throughout January 25 and 26 all three elements showed marked fluctuations without departing greatly from the usual diurnal curves.
The secret of Earth‐currents
Authors: Nippoldt A.
Published: February 2008

Most investigators who look for the secret of the earth‐current come from the study of terrestrial magnetism and hence it is easy to understand that they expect to find here analogous conditions. The first published curves of the diurnal variation of earth‐currents for a considerable period of time are the well‐known Berlin curves. These, indeed, have the appearance of some form of magnetic curves; some show changes during the night with superposition of a large variation during the daylight hours, very similar to the well‐known type of magnetic variations for the greater part of the Earth. Accordingly, it was erroneously expected in most cases, if not for the whole Earth, to find the same type of diurnal variation of earth‐currents as at Berlin, a similarity at the different observatories in terrestrial electricity as in terrestrial magnetism.
Cheltenham Magnetic Observatory April to June, 1936
Authors: Ludy Albert K.
Published: February 2008

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

April 17‐24—A period of disturbance, prolonged but not of great amplitude, began at 18h GMT April 17 and extended to the end of April 23. It had two outstanding features, (a) a bay lasting about an hour beginning April 18 about 5h when the declination increased 44′, the horizontal intensity 105 gammas, and the vertical intensity 116 gammas; (b) a time of short‐period fluctuations in declination and horizontal intensity lasting about thirty hours on April 21 and 22.
The magnetic character of the year 1935 and the numerical magnetic character of days 1935
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1935 has been drawn up in the same manner as for the preceding year1. Fifty‐one observatories contributed to the quarterly tables; forty‐seven of them sent complete data.

Table 1 (reproduced from Table II of the annual review) contains the mean character of each day for each month. The lists of calm days and disturbed clays, and the days recommended for reproduction are also reprinted here as Table 2.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

Terrestrial magnetism—Terrestrial magnetism and terrestrial electricity each present a basic problem, namely, that of the origin and maintenance of the Earth's magnetic and electric fields. Although the cause of the permanent magnetic field of the Earth has not yet been determined, definite progress has been made in the understanding of its fluctuations, all of which except those of long period—that is, the secular change—are demonstrably due to two causes; one acts above the Earth while the other acts within it. The more rapidly varying aspects of magnetic effects of internal origin seem attributable to induced electric currents circulating within the conducting substance of the Earth. Manifestations of these earth‐currents have been registered at the Department's observatories for more than a decade. Through cooperation with other organizations, similar registrations have been obtained from several other widely separated places. Thus, during the past year, it became possible to construct a world‐map of the electric currents circulating within the Earth and of their shift from place to place throughout the day.
Alfred Nippoldt, 1874–1936
Authors: Bock R.
Published: February 2008

Am 4. Oktober 1936 verschied plötzlich nach kurzer Krankheit der Direktor des Magnetischen Observatoriums der Universität Berlin, Prof. Dr. Alfred Nippoldt.

Noch wohlgemut hatte er die Reise nach Edinbourgh angetreten, um bei der Tagung der Union géodésique et géophysique internationale die deutsche erdmagnetische Forschung zu vertreten. Aber ein plötzlich auftretendes inneres Leiden zwang ihn, in London Heilung zu suchen und die Reise abzubrechen. Nach wenigen Tagen raffte er sich zur Rückreise in die Heimat auf. Die eingetretene Besserung war jedoch trügerisch, und nur zehn Tage liess ihn das unerbittliche Geschick freudvoll in seinem Heim auf Genesung hoffen.
Note on ionospheric disturbance of November 3 and 4, 1936
Authors: Seaton S. L.
Published: February 2008

An ionospheric disturbance in the F (highest) region of the ionosphere was observed by S. L. Seaton at the Watheroo Magnetic Observatory November 3 and 4, 1936. The disturbance apparently reached its maximum intensity November 4. On this date the critical frequencies for the F‐region remained below 6.2 megacycles per second throughout the day as compared to average values of more than 11.0 megacycles per second observed during the daytime on previous and following days. Because of the low values of critical frequency, it was impossible to determine whether the upper region observed was the F1‐ or F2‐region, but it is probable that the ionization of the F2‐region fell below that of the F1‐region during this period so that it was entirely unobservable.
Provisional sunspot‐numbers for December, 1936, and January and February, 1937
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
Huancayo Magnetic Observatory November to December, 1936
Authors: Davies Frank T.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 75° 20′.4 or 5h 01m.4 W. of Gr.)

November 2—This was a very brief disturbance with sudden commencement in all three elements. After 14h 20m GMT, H increased seven gammas in one minute, decreased 18 gammas in two minutes, increased 127 gammas in three minutes, and decreased 60 gammas to normal value at 14h 32m. After 14h 22m D decreased 1′ in two minutes, increased 3′ in three minutes, and decreased 2′ in five minutes to normal value at 14h 32m. After 14h 22m Z increased six gammas in four minutes and then decreased eight gammas in four minutes to normal value at 14h 32m. Prior to and following this 12‐minute interval of disturbance the magnetic records were undisturbed.
Watheroo Magnetic Observatory October to December, 1936
Authors: Green J. W.
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)

October 9–10—A minor disturbance was ushered in by a sudden commencement at 7h 26m 50s GMT, October 9, as shown by the record from the vertical‐intensity inductometer. Westerly D decreased 4′ in seven minutes, H increased 16 gammas in six minutes, and the numerical value of Z decreased 7 gammas in six minutes. The period of slightly disturbed magnetic conditions continued until 16h, October 10.
The electric current‐systems of magnetic storms
Authors: Goldie A. H. R.
Published: February 2008

In “Terrestrial Magnetism and Atmospheric Electricity,” Volume 40, No. 4 (December 1935), in a paper under the above title, Professor S. Chapman refers to some work on the same subject by the present writer. Besides replying to certain questions raised by Professor Chapman the writer would like to comment on features of interest and special difficulty.

(1) On page 365 Chapman notes that though his own results and mine are in general agreement and point to maximum currents of the same order, the values given by me for ten of the greatest storms of the year 1926 are about twice as great as those derivable from the storms dealt with in his paper No. 1. Later he remarks that if these ten storms were on the average twice as great as those dealt with in his paper, the difference in results would be natural.
Our knowledge of the lunar‐diurnal variation of the magnetic declination and new results obtained from observations at Mogadiscio
Authors: Bossolasco M. , Egedal J.
Published: February 2008

The opinion that the magnetic diurnal variations also depend on the magnetic elements in the place where they have been recorded, has been set forth by Ad. Schmidt; thereafter the question has been treated occasionally, most recently in a paper by A. G. McNish

For this question the magnetic observations made during the Polar Year at Mogadiscio are of special interest because the magnetic observatory there lay in the northern geographic but in the southern magnetic hemisphere, in other words, the Observatory lay between the geographic and the magnetic equators.
Magnetic secular change in Sweden, 1929–1936
Authors: Ljungdahl Gustaf S.
Published: February 2008

Preliminary values of the average secular change of declination, inclination, and horizontal intensity from 46 remeasured field‐stations are given as functions of geographical latitude and longitude.
The electrical characterization of days—The practice of the British Meteorological Office
Authors: Whipple F. J. W.
Published: February 2008

The subject of the electrical characterization of days was on the agenda of the Lisbon meeting of the International Association for Terrestrial Magnetism and Electricity in 1933. Two papers, one by O. H. Gish and the other by O. W. Torreson, were communicated and a Committee was formed to deal with the subject. In his paper Gish remarks (p. 225 of the Comptes Rendus) that the long experience in the use of these character‐numbers at the observatories of the British Meteorological Office would enhance the interest in a statement from that office regarding the full purpose and the merits of the scheme. The following note has been prepared in response to this suggestion.
Study of radio fade‐outs
Authors: Berkner L. V. , Wells H. W.
Published: February 2008

The radio fade‐out effect reported by Dellinger and Jouaust can be studied from the echo‐disappearance observed on the ionospheric traces during such disturbances. Twenty months of continuous data from Huancayo (Peru) and five months of data from Watheroo (Western Australia) are analyzed. The data are presented in more quantitative form than heretofore available. The results are in general agreement with the reports of Dellinger except that no recurrence or quasi‐recurrence tendency can be shown from the data available. It is concluded that the data support Dellinger's hypothesis of the origin of these effects in bright chromospheric eruptions and that the effect is an absorption of high‐frequency radio waves in the region between about 60 and 100 km because of increase of ionization. The higher ionospheric regions are apparently unaffected, indicating no appreciable absorption of the radiation causing the fade‐out, in these regions.
American URSI broadcasts of cosmic data, January to March, 1937
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant 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 Atmospheric 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 the mean value of k for Mount Wilson was 0.53 during 1936.
The aurora of February 2, 1937
Authors: Currie B. W.
Published: February 2008

A number of letters have been received at the University of Saskatchewan from persons located approximately in latitude 54° north and longitude 107° west, describing what was undoubtedly a red aurora on the night of February 2, 1937. The color of the aurora was described variously as red, crimson, and blood‐red. All reports emphasized the lack of the usual auroral colors. One correspondent, when he saw the display appearing on the horizon, thought that his neighbor's barn was afire and had gone to his assistance.
Auroral display of April 26, 1937, at Burlington, Vermont
Authors: Butterfield Arthur D.
Published: February 2008

The auroral display of April 26, 1937, was first noticed by a former student of mine, A. A. Hutchins, now living at Essex Junction, Vermont. At 22h 10m (75° meridian mean time) he happened to go outside his house and the peculiar appearance of the sky almost actually frightened him. The following is quoted from his description:

“I felt that I was inside a conical tent the top of which was just a little south of the zenith and from all around the horizon in a complete circle there were streamers ascending to the zenith. At first the color was like silvery white, then suddenly changed to a dark red for just a moment, and later to a greenish blue. At times the intensity would diminish a little on one side and then come in with greater intensity.”
Suggested magnetic nomenclature
Authors: Weinberg Boris
Published: February 2008

The introduction of the concept and the term “isopor” has so greatly increased the interest in studies of the secular variation of the geomagnetic elements that the time seems ripe to expand this concept. Therefore, I venture to propose designating the isopor of D, I, H, Z, etc., by “isallogons,” “isalloclins,” “isallodynams,” or specially “isallo‐H‐dynams,” “isallo‐Z‐dynams,” etc.

Perhaps it would be still more expedient to adopt a general name of “E′t‐isoline” for isolines of annual variation E′t of a geomagnetic element E or of gradients E′ϕ;, E′λ, E′h along the latitude ϕ, the longitude λ, and the height h above sea‐level.
Apia Observatory January to March, 1937
Authors: Dyer W. Ralph
Published: February 2008

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

February 2–5—A fairly intense magnetic disturbance commenced suddenly at 23h 02m GMT, February 2. The Z‐trace showed considerable fluctuations during February 3 but unfortunately records of H and D were not obtained until 20h, February 3. The H‐ and D‐traces were moderately disturbed during February 4 and 5 and gradually returned to normal.
Measurement of air‐potentials by the leak‐free and null method
Authors: Sherman K. L.
Published: February 2008

The purpose of this paper is to report further on a leak‐free and null method of making electrostatic measurements. The method and some results obtained when applied to observations of air‐potentials have previously been given. Whereas the leak‐free feature of the method was stressed in that report, it is desired now to emphasize some of its other advantages and to describe small, convenient units designed to replace the more cumbersome apparatus assembled in the laboratory for the preliminary trials.

Reports from persons who have used the method have consistently indicated that it is worth while adopting because of the ease of observation and reduction of the data even though the leak‐free feature is not used. Although the circuit is somewhat more complex than the conventional one and so requires slightly more time to prepare for an observation, the total time of a set of observations is less with this method because it saves the time required to calibrate the electrometer and to convert the electrometer‐readings to volts.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, April, May, and June, 1937
Authors: Nicholson Seth B. , Sternberg Mulders Elizabeth E.
Published: February 2008

The magnetic storm from April 24 to 28 could be described as a series of three storms separated by quiescent periods lasting a few hours. The second active period began suddenly at 15h 47m.5, April 25, the third at 18h, April 26. During these storms two sunspot‐groups were very active. The smaller one crossed the central meridian on April 23.3 in latitude 24° north, the larger on April 24.7 in latitude 19° north.

The storm of June 5 was probably caused by activity in the group which crossed the central meridian on June 4.8 in latitude 13° north.
Huancayo Magnetic Observatory May to June, 1937
Authors: Davies Frank T.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 75° 20′.4 or 5h 01m.4 W. of Gr.)

May conditions—The average character‐number for May was low, namely 0.1. Only three days during the month were classed as other than zero‐days. These were May 4, 5, and 28. May 5 was very disturbed. Two sudden commencements occurred during the month.
Watheroo Magnetic Observatory May to June, 1937
Authors: Green J. W.
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)

May 28—There was a sudden commencement at 01h 51m 50s GMT, May 28, as shown by the record of the Crichton‐Mitchell vertical‐intensity inductometer. D suddenly moved 1′ westerly, then 3′ easterly in about forty seconds, followed by a movement 5′ westerly in two minutes. H suddenly increased 5 gammas, then decreased 17 gammas in about forty seconds; these movements were followed by an increase of 18 gammas in two minutes. The numerical value of Z suddenly increased 4 gammas then decreased 13 gammas in about forty seconds; then followed an increase of 20 gammas in three minutes. The character of the trace was “1” during the next twenty‐four hours.
The heating of the ionosphere by the electric currents associated with geomagnetic variations
Authors: Chapman S.
Published: February 2008

§1. The transient geomagnetic variations (periodic and irregular) appear to be due mainly to primary electric currents flowing somewhere in the ionosphere, and in smaller degree to secondary currents induced within the Earth by the primary currents. These currents must heat the medium in which they flow, and the purpose of this note is to estimate the magnitude of this heating in the ionosphere.

§2. Schuster in his important 1907 memoir on S, the solar daily magnetic variation, remarked as follows on the heating of the atmosphere associated with S:
The heating of the Earth and oceans by induced electric currents
Authors: Chapman S.
Published: February 2008

§1. This note is a sequel to the preceding paper, in which the heating of the ionosphere by electric currents is considered. The ionospheric currents induce secondary currents in the Earth and oceans, whose magnetic effect appreciably modifies the transient magnetic variations at the Earth's surface. The possible interest of the heating‐effect of these induced currents was first drawn to my notice in 1935 by Drs. R. E. Gibson and F. E. Wright of the Geophysical Laboratory of the Carnegie Institution of Washington, who pointed out to me that if, as the analysis of magnetic records has shown, the main induced earth‐currents flow at a depth of 200 km or more, any heat there generated will have much difficulty in escaping; hence a very small rate of heat‐generation may be of importance. This led to my examination of the problem, with the result, perhaps to be expected, that the rate of this generation of heat is found in fact to be of too low an order of magnitude to be important, even if the heat accumulated without any escape, over the long life of the Earth, taken as 1010 years.
Provisional sunspot‐numbers for September and October, 1937
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
Remarks on Dr. Chapman's note on radio fade‐outs and the associated magnetic disturbances
Authors: McNish A. G.
Published: February 2008

It must be recognized that the special type of magnetic disturbance now known to be associated with radio fade‐outs and bright chromospheric eruptions was discerned as a special type of disturbance in Birkeland's masterful treatise on magnetic storms. The disturbance on October 6, 1902, which he designates as a “cyclo‐median storm,” is clearly of this class. The writer overlooked this discovery because 18 of the 19 perturbations described by Birkeland were characterized by auroral‐zone activity, and even the perturbation of October 6 was confused by representation of overhead currents at Axelöen, a high‐latitude station. Birkeland's remarkable insight caused him to point out in the description of the disturbance that the current‐flow over Axelöen was probably independent of that exhibited in low and middle latitudes.
Cheltenham Magnetic Observatory July to September, 1937
Authors: Ludy Albert K.
Published: February 2008

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

July 9–10—A mild disturbance began abruptly, but with small displacements, at 11h 43m GMT, July 9. It ended at 10h, July 10. Ranges: D, 27′; H, 128 gammas; Z, 45 gammas.
Huancayo Magnetic Observatory July to September, 1937
Authors: Davies Frank T.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 75° 20′.4 or 5h 01m.4 W. of Gr.)

July 9—At 11h 44m GMT, July 9, there was a sudden commencement with small increases in D, H, and Z.
Note on ionospheric disturbance at Watheroo Magnetic Observatory, June 23, 1937
Authors: Seaton S. L. , Hogan T. Kevin
Published: February 2008

Ionospheric observations of June 23, 1937, showed a disturbance of the F2‐region in the form of a rapid increase of ionization lasting for about 30 minutes. There was no apparent simultaneous magnetic effect. At 10:15, 120° east meridian time, a distinct weakening of echoes was observed. This was not any characteristic of the transmitter because normally echoes are stronger at six me per sec—the frequency observed at 15 minutes past the hour.
Apia Observatory, October to December 1937
Authors: Wadsworth J.
Published: February 2008

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

October 1–13—A magnetic storm commenced at 13h 44m GMT, September 30, with a sudden increase of 20 gammas in H, 6 gammas in Z, and a slight decrease in the easterly declination. This marked the beginning of a disturbed period during which there appeared to be four phases of activity. From the maximum at 15h 34m, September 30, H decreased through a range of 152 gammas to a maximum at 06h 43m, October 1. Another sudden increase of 22 gammas in H at 11h 21m, October 3, was the beginning of more intense activity and the rapid decrease in H on October 4 resulted in a minimum which was too low to be recorded, but the measurable range was 225 gammas. Unfortunately the Z clock stopped on October 3 and the record October 3–4 was missed. There was a period on October 6 during which H, D, and Z showed rapid oscillations of small amplitude which were well defined between 17h and 19h. Conditions appeared to be approaching normal when another disturbance commenced abruptly at 05h 21m, October 7. There was a range of 162 gammas in H associated with this storm. After a short lull, conditions again became disturbed on October 9 between 06h and 07h. The traces showed that the magnetic elements were relatively quiet by October 13 and there were no further disturbances of importance during the remainder of the quarter.
An electromagnetic method of determining induction‐coefficients of magnetometer‐magnets
Authors: Nelson J. H.
Published: February 2008

If a piece of iron or steel is placed in a magnetic field it is magnetized by induction. This is true whether the iron or steel is already permanently magnetized or not. Suppose that a permanent magnet is placed in a magnetic field parallel to the direction of the magnet, that is, so that no torque results from the action of the field on the magnet. The strength or magnetic moment of the magnet will be increased (or decreased, if the field of the magnet opposes the applied surrounding field) by induction.
The ionosphere at Huancayo, Peru, November and December 1937
Authors: Wells H. W. , Stanton H. E.
Published: February 2008

On November 17, 1937, at the Huancayo Magnetic Observatory, in Peru, of the Department of Terrestrial Magnetism, Carnegie Institution of Washington, continuous operation of recently‐developed ionospheric apparatus1 was started. (Identical equipment was installed at the Watheroo Magnetic Observatory in Western Australia during April and May 1938.) The new apparatus covers frequencies from 16.0 mc/sec to 0.516 mc/sec every 15 minutes, automatically registering the virtual heights of the ionospheric regions. It is a powerful tool for radio exploration of the Earth's outer atmosphere, and its continuous operation is likely to give an excellent picture of the ionosphere.
On the diurnal variation of the magnetic pole
Authors: Wasserfall K. F.
Published: February 2008

Introduction—When Roald Amundsen planned his Expedition with the Gjöa he studied the practical side of the earthmagnetic science at the Observatory at Potsdam, where Ad. Schmidt acted as his chief tutor. Professor Schmidt was personally very interested in this Expedition, especially because it offered the rare opportunity to obtain magnetic observations suitable for fixing the geographical coordinates of the magnetic pole.

For use during the Expedition Schmidt provided Amundsen with written instructions, which have been published in part in the magnetic results of the Expedition [see 1 under “References” at end of paper]. Here Schmidt writes: “For an approximate calculation we may accept the following values for the magnetic elements at the surface of the globe in the neighborhood of the magnetic north‐pole: Vertical intensity, V = 62000γ; inclination, I = 90° − 0′.5a, at a distance of a miles from the pole; horizontal intensity, H = 9 × aγ at a distance of a miles from the pole (one mile = 1.852 km). Thus we may, with sufficient accuracy, calculate horizontal intensity by aid of inclination or vice versa, since to each minute by which the inclination is less that 90°, corresponds 18γ, in the horizontal intensity, and we have accordingly Table 1.
American URSI broadcasts of cosmic data, April to June 1938, with American magnetic character‐figure CA, May to July 1938
Authors: Johnston H. F.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant 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 Atmospheric 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 foot‐note to the Table.
Soviet polar magnetic observatories
Authors: Harradon H. D.
Published: February 2008

The Union of Socialistic Soviet Republics is in an especially favorable situation for securing magnetic and other geophysical observations in the polar regions since it possesses an unusually great extent of territory lying within the Arctic Circle. That this opportunity is not being neglected is apparent from the fact that there are at present no less than five permanent polar magnetic observatories in the U.S.S.R., operated by the Central Administration of the Northern Sea Route, namely, Matochkin Shar, Calm Bay, Dickson, Cheliuskin, and Wellen. The establishment of these observatories took place at different times and under different conditions and hence they are not uniform as regards methods and arrangements for work.
Tucson Magnetic Observatory, April to June 1938
Authors: Hershberger John
Published: February 2008

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

April 13–15—A moderate storm began sharply at 11h41m GMT, April 13, with a sudden increase in H of 81 gammas, followed immediately by a decrease of 56 gammas. Numerous similar quick thrusts in H were the chief characteristic of the storm, which lasted until about 01h, April 15. H was somewhat depressed during part of the period, but not greatly at any time.
Apia Observatory, April to June 1938
Authors: Wadsworth J.
Published: February 2008

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

April 13–15—At 11h 42m GMT, April 13, a sudden increase of 34 gammas in H marked the beginning of a disturbed period which lasted until early on April 15. The range in H was 161 gammas.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

The year ended June 30, 1938 has been marked by energetic prosecution of experimental investigation and continued coordination and integration of various researches paving the way for more general formulation of geophysical facts. Good progress has been made in two major projects which open new fields of investigation and promise important advances. One of these is the completion of the Atomic‐Physics Observatory (see Fig. 1) and the considerable progress in the installation of the electrical equipment. The electrostatic generator and tube are designed to operate at potentials exceeding five million volts and offer unique opportunity for further studies in the expanding field of nuclear physics—a field to which we must look for additional understanding of magnetic phenomena.
Correlation of magnetic activity with disturbance of radio transmission
Authors: McNish A. G. , Johnston H. F.
Published: February 2008

Owing to their mutual dependence on conditions in the ionosphere a close connection between magnetic activity and radio transmission is expected. This connection is revealed by impairment of transmission on high frequencies during magnetic storms, ranging from complete failure of certain channels of communication during severe magnetic storms to minor vitiation during periods of lesser activity.

The first experimental evidence on the nature of the changes taking place in the reflecting properties of the ionosphere during a magnetic storm were supplied by Hafstad and Tuve (see 1 under “References” at end of this article) in 1929. Limitations in technique at that time prevented comprehensive observation of the changes taking place. Subsequent developments in methods of ionospheric research at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington and elsewhere, particularly the introduction of automatic multifrequency methods [2, 3] have afforded a clearer understanding of the phenomena.