bluuebunny/crossref_metadata_2025 huggingface dataset:
Ueber die Selbstaufladung korpuskular strahlender Koerper
Authors: Schweidler Von E.
Published: February 2008

Summary.—1. The observed phenomena, which have led to hypotheses regarding the existence of corpuscular cosmic rays, are briefly discussed and the importance is pointed out of deducing the theoretical consequences resulting from the charged state of the emitting cosmic bodies. 2. The characteristics of corpuscular rays are discussed, especially the “radiation potential,” P (quotient of the kinetic energy and the electric charge of a particle), and the magnetic deflectibility. 3. The stationary charge of a sphere, which spontaneously emits corpuscular rays into a surrounding vacuum, is computed; it is larger than the product Pa (“radiation potential” times radius of sphere), and increases with intensity of emission; the emitted particles are compelled to turn back at a distance A, the values of which are computed; numerical examples for the Moon, as the supposed source of radiation, are added. 4. The stationary charge during simultaneous spontaneous emission of positive and negative corpuscular rays is computed. 5. Analogous calculations are made on the assumption that a sphere with a strongly ionized surface emits a spontaneous radiation and hence on account of its charging, a compensating field‐driven ion‐radiation is emitted; in an equilibrium condition, therefore, at a great distance, there exist both positive and negative rays of equal average intensity and equal velocity; the results are applied to the case of the Sun and several numerical examples are given.
On the secular variation of the magnetic declination in Ekaterinburg and Siberia
Authors: Abels Robert
Published: February 2008

Using as a basis the magnetic observations made by Dr. A. Smirnow in 1900, 1901, and 1909, and those in 1916, by the author of the present paper, as well as the observations at the Ekaterinburg Observatory, it is found that the magnetic needle reached recently in Siberia its maximum eastern declination and that it has begun its reverse movement towards the west.

At Ekaterinburg, the north end of the needle, since 1761, when the first determinations were made, until the year 1916, has moved constantly towards the east with a mean annual change of about four minutes. In 1761 the value of the declination was 0°50′E; in 1916, 11°03.′8 E. For the year 1917, however, the annual mean value as obtained from the hourly observations at the Observatory, amounted to 11°03.′7 E and for 1918, 11°03.′4 E. Accordingly, the needle remained stationary during 1916–1917, and in the following year moved 0.′3 towards the west. It may be expected, therefore, that it will now continue to move toward the west.1
Preliminary report on the atmospheric potential‐gradient recorded at the Apia Observatory, Western Samoa, May 1922 to April 1924
Authors: Thomson Andrew
Published: February 2008

The paper gives preliminary summaries of the atmospheric potential‐gradient data from continuous records obtained, under the auspices of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, at the Apia Observatory for two years during May 1922 to April 1924. The diurnal variation in the potential‐gradient is determined from those days on which no negative potential occurred and its outstanding features are two maxima at about 8 a.m. and 7 p.m., local mean time.
Ueber schematische magnete
Authors: Schmidt Ad.
Published: February 2008

Für die genäherte Berechnung der Wirkungen eines regulären Magnets genügt es oft, ihn durch einen Elementarmagnet ersetzt zu denken. Eine engere Annäherung erhält man, wenn man statt dessen einen sogenannten schematischen, d. h. einen solchen Magnet wählt, dessen gesamte Magnetisierung in zwei Polpunkten vereinigt gedacht wird.

Der Gedanke liegt nahe, die Annäherung dadurch noch weiter zu treiben, dass man die Anzahl der Polpunkte vermehrt oder, was auf dasselbe hinauskommt, mehrere schematische Magnete verbindet. Dies kann in manchen Fällen — ein solcher hat die vorliegenden Ausführungen veranlasst — auch deshalb von Wert sein, weil sich die Wirkung eines Poles (im Gegensatz zu der einer stetigen Raumerfüllung) sehr einfach mit jeder geforderten Genauigkeit berechnen lässt.
Preliminary lines of equal annual change of the magnetic elements in 1915, for Latin America and adjacent waters
Authors: Fisk H. W.
Published: February 2008

Introduction.—Magnetic observations have been made by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, in some part of the area indicated in the title, every year since 1905. At the conclusion some time in 1925, of the work of an observer now in South America, the project undertaken in 1922, of reoccupying selected stations distributed with fair uniformity over the entire land area of the western hemisphere south of 33° north latitude, will have been completed, and a series of observations of recent date will be available for the study of secular variation. Before undertaking a mathematical discussion of this material, it is advisable to determine the general character of the lines of equal annual change of the three elements, declination, inclination and horizontal intensity, by a general review of the data, and the construction by simple graphical processes of preliminary charts showing the lines for some suitable epoch.
Results of magnetic observations made at the magnetic and meteorological observatory, Irkutsk, Asiatic Russia, 1916–1920
Authors: Schostakowitsch W. B. , Pödder A. I.
Published: February 2008

The results given in Table 1 are based on the observations made by the Magnetic Division of the Observatory, at a site 26 km. from Irkutsk, in latitude 52° 27′.6 N, and longitude 104° 02′.3 East of Greenwich.

For the photographic registration of the magnetic elements there were in use the Edelmann magnetograph, with eye‐reading telescopes, and the Eschenhagen magnetograph. The activity of the Division was normal until 1919; thereafter, difficulties were encountered owing to lack of photographic paper, lack of petroleum for the motor used in the generating plane for the magnetograph electric lights, and gradual reduction of personnel. In consequence of these adverse circumstances, the activity of the Division was necessarily decreased.
Principal Magnetic Storms recorded at the Apia Observatory, January to June, 1924
Authors: Thomson Andrew , Westland C. J.
Published: February 2008

(Latitude, 13° 48′.4 S.; Longitude, 171° 46′, or 11h 27m.1 W, of Greenwich.)
A differential method for deriving magnetometer deflection‐constants
Authors: Fisk H. W. , Duvall C. R.
Published: February 2008

For the computation of the horizontal component of the Earth's magnetic field from the observed angle of deflection of one magnet by a second in Lamont's first position a factor, intrinsically a function of the dimensions of the magnets employed, is required to correct for these finite dimensions. The so‐called “distribution‐coefficients” concerned in this factor are generally determined by means of a rather tedious computation depending on the data observed at three deflection‐distances. Theoretically the ratio of the sines (or the difference of the logarithmic sines) of the observed angles of deflection for any two distances is constant for a given instrument and pair of magnets; differential methods based on this theoretical condition are developed which simplify the computations required.

The more exact form of the distribution‐factor, (1+Pr−2+Qr−4), is found to be less satisfactory in practice than the simpler form (1+P′r−2) for magnets which have been designed to make the value Q as small as possible (theoretically zero), on account of the greater sensitiveness to changes in the sine‐ratios of the factor containing both P and Q. The paper includes numerical examples and tabulations to show the application of the derived formulas to the determination of distribution‐coefficients, constants, and corrections on standard for a number of magnetic instruments of the Carnegie Institution of Washington.
Studies on terrestrial magnetism, resume of observations at Lukiapang Observatory, 1918, 1920, and 1924
Authors: de Moidrey J.
Published: February 2008

Not many magnetic stations—Pola, Bombay and perhaps a few others—have published a summary cf long series of observations. There is in general only the yearly bulletin, but to work up results from a set of many bulky volumes requires considerable labor. Lukiapang Observatory is carrying on compilations from the 50‐years' records at Zi‐ka‐wei and the present station (Lukiapang). These summaries are not arranged according to a predetermined scheme, but are detached studies.
Regarding abruptly‐beginning magnetic disturbances
Authors: Bauer Louis A. , Peters W. J.
Published: February 2008

Several recent investigations have indicated that the Earth's magnetic field has an appreciable effect on the electric waves used in wireless telegraphy and that there is a distinct relationship between terrestrial magnetic disturbances and certain radio phenomena. In view of these facts and of an action taken at the Madrid meeting of the International Section of Terrestrial Magnetism and Electricity, last October, a preliminary investigation was made by the authors regarding the outstanding question as to the simultaneity, or non‐simultaneity, of abruptly‐beginning magnetic disturbances, the definite settlement of which is likely to have an important bearing on the theory of the Earth's magnetic storms and their connection with the phenomena of radiotelegraphy, noted above. The present preliminary communication is an extension of the first author's investigations of 1910.

The present results apparently indicate that even with the aid of the magnetograms ordinarily obtained at magnetic observatories, appreciable differences in the absolute times of beginning of abrupt disturbances can be detected, which, on the average, increase with increasing magnetic latitude, the correlation coefficient being about 0.75. The average speed of progression, as derived from 30 abrupt disturbances, during periods of high and low sunspot activity, apparently would be 100 cm. per second, so that the uninterrupted progression of an average abrupt disturbance, from the magnetic equator to the magnetic pole, might take about 1.8 minutes. These results are regarded merely as a working hypothesis for further examination when more extensive data are available.
Declination results obtained at the time of the total solar eclipse, January 24, 1925, at Long's Corners, Ontario, Canada
Authors: French C. A.
Published: February 2008

The accompanying declination results were obtained at the time of the total solar eclipse of January 24, 1925, at Long's Corners, near Hamilton, Ontario. In addition to the declination values, the following data are applicable to the station: Latitude, 43° 12′N; longitude, 79° 51′W; inclination, 74° 22′N; and horizontal intensity, 0.16140 C.G.S.

The declination observations were carried out as nearly as possible according to the general scheme received from the Carnegie Institution of Washington (Department of Terrestrial Magnetism), just prior to the eclipse of 1925 and the more detailed scheme issued prior to the eclipse of September, 1922.
On the periodicity of magnetic storms at Irkutsk, Siberia
Authors: Pödder Arnold
Published: February 2008

The following investigation is based on the hourly readings of the magnetometers (1887–1905) and on the measurements of the Edelmann magnetographs (1906–1919) at the Irkutsk Meteorological and Magnetical observatory.

In Table 1 the number of magnetic storms, or of major disturbances, are tabulated according to months and years. In this connection, I have considered all the cases in which at least one of the following conditions for the range, or magnitude of the disturbance, is satisfied:D≧1°;H≧0.0500 C.G.S.;Z≧0.500 C.G.S.
Aurora, magnetic storms, and difficulties in radio reception, 1924–1925
Authors: Ulrich Franklin P.
Published: February 2008

The program of work covered by the report consists of 3 parts, namely, (a) the observation of aurora at the Sitka Magnetic Observatory of the U. S. Coast and Geodetic Survey, (b) reports of aurora observed and difficulties in radio and cable reception from the various radio and cable stations throughout Alaska, and (c) comparison of these observations and reports with the elements of the Earth's magnetic field as recorded on the magnetograph at the Sitka Observatory, during the period covered by the report, August 1924 to May 1925. The cooperating stations were as follows: 11 of the U.S. Signal Corps cable stations, 13 of the U.S. Signal Corps radio stations, and 7 of the U.S. Navy radio stations.

The several deductions based on the reports and observations for the period 1924–1925, together with a comparison of the deductions based on the corresponding data for 1923–1924, are summarized by the author as follows:
Magnetic observations by the Swiss expedition to Greenland 1912–1913
Authors: Mercanton Paul L.
Published: February 2008

Observations of the declination, D, were to serve especially to determine the route to be followed. It was sufficient to determine it to 0°.l. Besides since variations, or disturbances, may be of the order of a degree, or more, and as the Expedition could not refer its observations to a base station, more precise observations would have been illusory. The observations were made by means of solar azimuths taken with the portable Hildebrand theodolite and excellent chronometers.
Summary of the chief magnetic results of the GJÖA Expedition, 1903–06
Authors: Russeltvedt Nils , Graarud Aage
Published: February 2008

The following explanatory information may be given for Tables I–IX:

On his way to Gjöahavn, Captain Roald Amundsen made magnetic observations at the two stations, Godhavn and Beechey Island. During the stay at Gjöahavn the immediate neighborhood of the base‐station was closely surveyed. The mean values of the magnetic elements at these stations (Nos. 1–13) will be found in Table VIII. Near the Magnetic North Pole, Amundsen observed at three stations, Nos. II, III and IV; however, the region between 69°N and 70°N is represented by but a single station, No. I. The geographic positions of the stations and of the Magnetic North Pole are shown m Figure 1.
Magnetic storm of January 26, 1926, as recorded at the Sitka Magnetic Observatory
Authors: Jones E. Lester
Published: February 2008

The foregoing information regarding the magnetic storm of January 26, 1926, as recorded at the Sitka Observatory, has been prepared from the monthly tabulation of hourly values. The magnetograms have not yet been sent in, so that the exact time of beginning and more details regarding phases can not be given at present date (March 18).
Magnetic storm of January 26, 1926, at Apia
Authors: Westland C. J.
Published: February 2008

We had a rather spectacular magnetic storm on January 26 to 27, 1926. A part of the horizontal‐intensity record looks almost like a seismogram of a local earthquake. At one place there is a change of 100 gammas within 6 minutes. I had the same experience as in 1921.
Principal magnetic storms recorded at Antipolo, Rizal, near Manila, P.I., January to March 1926
Authors: Masó M. Saderra
Published: February 2008

(Latitude 14° 35′ 48′′N.; longitude 121° 10′ or 8h 04.m 7. of Greenwich.)

Besides the above, miner disturbances occurred as follows: January 18 at 9h to January 19 at 4h; January 22 at 15h 37m to January 23 at midnight; February 17 at 15h 36m to February 18 at 5h; March 5 at 10h 10m to March 6 at noon; March 9 at 5h 26m to March 10 at 8h 30m; and March 11 at 0h to March 12 at 4h 40m.
Request for literature on atmospheric electricity
Authors: Benndorf H. , Hess V. F.
Published: February 2008

We are planning to write an extensive treatise on atmospheric electricity which will be published next year.

On account of the well‐known shortage of funds of the libraries in Austrian Universities, it is extremely difficult for us to obtain foreign journals, especially the bulletins and proceedings of scientific institutions and societies in foreign countries.
Principal magnetic storms recorded at the Watheroo Magnetic Observatory for January to March, 1926
Authors: Johnston H. F.
Published: February 2008

(Latitude, 30° 19′.1S.; longitude, 115° 52′.6 or 7h 44m E. of Greenwich.)

January 22–23 and January 26–29,1926.—Notes on these storms are given on pages 23 to 25 of the March 1926 number of this Journal.
Note on magnetic storms of January 26–27, and April 14–16, 1926, at Irkutsk (Zouy) Observatory
Authors: Pödder Arnold
Published: February 2008

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

April 14, 1926.—A disturbance of considerable intensity began on April 14 at 14h 02m, with a sudden commencement. The horizontal intensity increased within six minutes of time by about 110γ. High values of H occurred at intervals until 20h with large fluctuations; within the next hour the force decreased greatly, the spot going beyond the limits of registration, remaining lost, except for brief periods, until 13h on April 15. A series of large fluctuations then brought the spot back to the paper, but the value remained low until the following day, when normal conditions were gradually resumed. The sudden commencement of this storm was also shown in the D and Z traces.
Études sur le Magnétisme Terrestre, 1877–1924, résumées par J.DE Moidrey, S.J.—Fascicule V
Authors: de Moidrey J.
Published: February 2008

Un nouveau fascicule vient continuer celui dont compterendu a été donné dans le Journal Tan dernier, p. 24.

La première Etude de cette fois a été plus particulièrement inspirée par différentes notes qui ont paru dans le Journal. C'est une revue détaillée de nos magnétogrammes de 1877 à 1924, au point de vue des marques qui sont dues ou ont pu être dues à des tremblements de terre. Les auteurs ne se sont pas limités au cas des macrosîsmes ni même à ceux où averti d'abord par les sismographes, l'observateur cherche si les magnétomètres ont aussi été agités. Tous les photogrammes ont été étudiés à la loupe avant aucun examen des sismogrammes. Il s'en est suivi une liste contenant des marques dont beaucoup sans doute n'ont rien de sismique. Mais nombre d'autres ont été relevées qui semblent dignes d'attention.
Some preliminary results of diurnal variation of magnetic inclination at field stations in South America
Authors: Fisk H. W.
Published: February 2008

The results of some of the field determinations of diurnal variation of inclination by means of observations with the earth inductor are reported; these show interesting characteristics at some of the stations along the Pacific coast of Peru and Chile. On January 27, 1917, which is one of the ten least disturbed days for the month, a total diurnal range of inclination of nearly 20′ was observed at Arequipa, Peru; observations in 1924 to 1926 show similar though somewhat smaller ranges at the same station and at other stations in the Andean region. An attempt to relate this unusual daily range to the altitude of the stations or to the nearness of high mountains has yielded only negative results. A method adopted for analyzing these partial daily curves by modification of Fourier series is described and illustrated; the resulting coefficients, though depending on Certain arbitrary assumptions, are useful in comparing curves from different stations and for transferring results to other stations where they are needed for correcting field observations to a common hour for secular‐variation discussions. By comparing the annual mean diurnal variation in inclination at the United States Coast and Geodetic Survey observatories with the field results here discussed, three zones for the American continents are shown within which the phase of the curves is reversed; because of the shifting of the times of maximum and minimum with the season, the central lines of these zones are only approximately determined, but they may be placed at about magnetic latitude 40° north, 0°, and 25° south.
Earthquakes registered on the Lukiapang Magnetographs in 1925
Authors: de Moidrey J.
Published: February 2008

The list of earthquakes contained in our last pamphlet (Études, XXIV) could not be kept in order without an amount of labor. Something like what is done at the Watheroo Magnetic Observatory would perhaps be acceptable. It is not yet time to give the epicenters, but we can supply the number of the Zikawei Bulletin and a calculated distance, also the phase which seems nearest.

The type can be given according to what is said (Études XXIV, p. ii, §iv).
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July to September, 1926
Authors: Hartnell Geo.
Published: February 2008

(Lat. 38°44′.0N.: long. 76°50′.5 or 5h07m,4 W. of Gr.)
Godhavn vertical‐intensity magnetometer
Authors: la Cour D.
Published: February 2008

Since the preparation of my article on this instrument, I have received a wireless report from Godhavn. Dr. Olsen states that from October 20, 1926, the new vertical‐intensity magnetometer has been in regular use. From October 20 to November 19 determinations have been made with the magnetometer on nine days at temperatures between +4°.2 and −10° Centigrade; on each day 6 readings were taken. Supposing the base‐line value of Z‐magnetograph constant during the 31 days, the means of the 6 readings taken each day show a mean departure from the (supposed) constant base‐value of 2.5γ (corresponding to a mean error of about ±0.8γ of the base‐line value for the 31 days).
Magnetic storm of March 5, 1926, at Godhavn Magnetic Observatory
Authors: la Cour D.
Published: February 2008

The following preliminary data apply to the setting in of the magnetic storm on March 5, 1926, at the Godhavn Magnetic Observatory.

(H = constant + tabular values; D = constant − tabular values.)
Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, January to March, 1927
Authors: Hartnell Geo.
Published: February 2008

(Lat. 38°44.′0 N.; long. 76°50.′5, or 5h07m.4 W. of Gr.)
Principal magnetic storms recorded at the Sitka Magnetic Observatory, January to March, 1927
Authors: Ulrich F. P.
Published: February 2008

(Latitude 57°03′.0 N.; longitude 135°20′.1, or 9h 01.3m W. of Greenwich.)
The aurora of September 20, 1926, Sitka, Alaska
Authors: Ulrich F. P.
Published: February 2008

One of the most striking auroras in recent years was observed throughout Alaska on the evening of September 20, 1926. This was pronounced one of the most beautiful ever seen in the Yukon valley where they are very frequent and where beautiful auroras are seen often. At Sitka, it is very seldom that one can see an aurora with so much coloring, such rapid changing and variations in form, and one that was so extensive that the whole sky was practically covered at times. Also, the coloring was very bright at times even though the Moon was full and shining brightly.
Computation of Fourier terms
Authors: Duvall C. R.
Published: February 2008

The general Fourier term is expressed either by means of the amplitude cn, and phase‐angle ϕn, thus

urn:x-wiley:00968013:media:tma31209:tma31209-math-0001
or by means of the Fourier coefficients, an and bn, thus

urn:x-wiley:00968013:media:tma31209:tma31209-math-0002

It is customary to compute the ordinates of the terms at equally‐spaced intervals of the variable angle θ, and usually at the values of θ for which the observed ordinates are given. This computation may be made by either of the above two formulæ. The second, however, can be used to considerable advantage when the assumed zero‐angle of the analyzed ordinates coincides with the angle of one of the equally‐spaced ordinates to be computed. It is especially advantageous when this assumed zero‐angle is the actual zero‐angle of the desired ordinates, in which case a table of values of cos nθ and sin nθ may be constructed for values of θ at the required equidistant intervals, and for values of n from 1 up to the number of terms desired. Arrange cos nθ and sin nθ in parallel lines. If the first line is multiplied by an and the second by bn and the products written in parallel lines, the sum of two corresponding products will be the computed ordinate of the nth wave at the corresponding value of θ. In forming the products and sums, advantage is taken of the fact that each of the three lines is a sine curve repeated n times. The sum of corresponding computed ordinates of all the waves gives the computed ordinate of the sum curve corresponding to the observed ordinate at that value of θ.
Principal magnetic storms recorded at the Sitka Magnetic Observatory, April to September, 1927
Authors: Ulrich F. P.
Published: February 2008

Two very large magnetic storms occurred during this quarter, July 21–22 and August 20–22.

On July 21 from normal values and regular smooth curves at 19h 03m, D increased abruptly 18′, H increased 10γ, followed immediately by a sudden decrease of 90γ, and Z increased 4γ, followed by a sudden decrease of 36γ. The storm was moderate until 1h 55m July 22, when the elements began to move considerably. Although there was considerable movement of the spots a good record was secured except for a short period around 8h where the fast motion of the curves makes the interpolation rather uncertain. At 21h July 22 the curves are normal and almost smooth. This storm is peculiar because of the prolonged high values of H during the first half of the storm.
The magnetic and electric observations of the Maud Expedition during 1918 to 1925
Authors: Fisk H. W. , Fleming J. A.
Published: February 2008

It is well recognized that the accumulation of additional reliable data in terrestrial magnetism and electricity in the polar regions is of first importance to the definite solution of unsolved problems both from the statistical and laboratory method of approach. The increased world‐wide interest in polar exploration evidenced, for example, by the rapidly‐developing plans of the International Society for the Exploration of the Arctic by Means of the Airship (Aeroarctic) and of the Byrd Antarctic Expedition, besides the already crowing: importance of establishing air‐routes in these regions, emphasizes the value of intensive scientific effort.

The possibilities of obtaining valuable data on polar expeditions despite the unusual and extreme conditions encountered as well as the handicap of limited personnel are well illustrated by the recently published admirable reports1 on the magnetic and electric observations of the Maud Expedition in the second part of Volume VI of the “Researches of the Department of Terrestrial Magnetism.” These reports give the results and discussion of the data obtained through cooperation of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington with the Maud Expedition, organized and directed by Captain Roald Amundsen. The scientific work was in charge of Dr. H. U. Sverdrup throughout. Because of the interest of the results to the readers of the JOURNAL it is thought desirable to summarize briefly the operations of the Expedition.
Tentative magnetic values as recorded at the Apia Observatory for the year 1927
Authors: Thomson Andrew , Westland C. J.
Published: February 2008

Continuous records of the declination and of the horizontal component of the Earth's magnetic field were obtained during 1927 at Apia Observatory, latitude 13°48′ south, longitude 171°48′ west. Owing to the length of time which must necessarily elapse before publication of the hourly values of these elements, it is considered desirable to announce tentative values which, although subject to revision, will probably remain unchanged. These data, as given in the following table, are based on the means of all the hourly values during the month giving the so‐called “all‐days value” for the magnetic element concerned:
Aurora and low‐frequency radio reception, July 7 to 8, 1928
Authors: Pickard Greenleaf W.
Published: February 2008

The aurora observed at Newton Centre, Massachusetts, began at 20h 15m Eastern Standard Time, July 7, as a bright arch in the northeast. An hour later an auroral crown developed near the zenith, with descending rays which at one time nearly filled the hemisphere, and which were at times strongly colored with pink and yellow‐green. Broadcast reception from WGY at Schenectady, and KDKA at Pittsburgh, was greatly depressed during the entire evening, and did not rise appreciably above its normal low daytime‐level. Although the Harvard Astronomical Laboratory at Cambridge has not yet reduced its record of WBBM for this period, Dr. Stetson reports very low field‐values.
Principal magnetic storms recorded at the Huancayo Magnetic Observatory, May to July, 1928
Authors: Ledig Paul G.
Published: February 2008

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

May 10–12, 1928—This prolonged magnetic disturbance, hardly severe enough to class as a storm, began suddenly in all three elements, the horizontal intensity increasing 71 gammas in six minutes. There were periods of quiet during the three days of disturbance, but the horizontal intensity was subnormal during the whole period, and the fluctuations were marked during the daily maximum.
The magnetic character of the year 1927 and review of the years 1917–1927
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1927 has been drawn up in the same manner as the preceding years; moreover it contains a review of the collaboration of the observatories during the years 1917–1927.

In 1927, 43 observatories contributed to the quarterly reviews; 41 of them sent complete data. Table II of the annual review, containing the mean character of each day and each month, the lists of calm days and of disturbed days and the days, recommended for reproduction, are reprinted here. (It will be recalled that at the meeting of the Commission for Terrestrial Magnetism and Atmospheric Electricity of the International Meteorological Committee at Zürich, September 17, 1926, it was agreed that certain days included amongst the five most disturbed days of the month, should not be included amongst the days selected for the calculation of the diurnal irregularities. Days of character 2.0 should be excluded and other highly disturbed days, on which loss of trace has occurred.)
Method in oscillations
Authors: McFarland W. N.
Published: February 2008

The aim of this paper is to develop the best arrangement of the oscillation‐observations of the measurement of horizontal intensity, by consideration of the relative precisions obtained by varying the length of the series and the method of computation. The variation of precision in the final mean value with arrangement of the observational and computational work is shown by a figure, and the formula is stated for the propagation of this observational error into the computed value of the horizontal intensity.
Preliminary results of ocean magnetic observations on the Carnegie from Callao to Samoa, February to March, 1929
Authors: Ault J. P.
Published: February 2008

The Carnegie sailed from Callao Bay under her own power at 15h 20m, February 5, using the engine until the next morning on account of calm. Here the regular observational program began with an ocean‐station, and continued without interruption, except for a stop of one day at Amanu Island, until arrival at Papeete, March 13. The weather was excellent, with no storms and good breezes. The engine was not required except when the trade‐wind was interrupted among the Tuamotu Islands and during the squally weather approaching Tahiti.
The magneto‐chronograph and its application to magnetic measurements
Authors: McComb H. E. , Huff C.
Published: February 2008

The period of a magnet oscillating under the directive force of the Earth's magnetic field is a function of the strength of that field. Heretofore the estimation of the period has been accomplished by eye‐and‐ear readings but in the present method the personal equation is entirely eliminated. Light from an intense source such as an automobile headlight lamp is condensed on the glass‐scale end of a magnetometer‐magnet and after reflection is focussed on a slit in front of a photo‐electric cell. The reflected beam acts as an optical lever whose period is the same as that of the magnet but whose amplitude is twice as great. At each transit of the image across the slit current is passed by the cell and after passing through amplifiers is made to operate a pen on a chronograph. A chronometer in the circuit marks seconds on the record by the same pen. In this investigation the method was applied in the determination of the moment of inertia of a magnetometer‐magnet, estimation of personal equation in eye‐and‐ear readings, and in preliminary tests of the relative absolute magnetometer.
A preliminary list of arctic magnetic determinations
Authors: Weinberg Boris
Published: February 2008

One of the chief aims of science is the economy of time for obtaining knowledge, and this circumstance justifies the efforts of those who are making summaries of experimental or observational results.

The usefulness of a summary depends, however, in a great degree on its completeness, because this quality only permits avoiding the difficulty of recurring to the original investigations and the still greater task of finding them. In the case of the magnetic determinations the attainment of completeness is close to an impossibility. Indeed, such observations are often found in books and articles the titles of which suggest no idea that they contain magnetic determinations. Thus, for example, “Observationes meteorologicæ factæ Petropoli annis MDCCLV. et MDCCLVI. St. V. et consectaria. Auctore I A. Brovn” (Novi. Comm. Acad. Petrop., v. 7, 388–408, 1761) or “Extrait d'une lettre relativement à un tremblement de terre qui a eu lieu à Odessa le 14/26 novembre 1829, adressée au secrétaire perpétuel par M. Hauy, membre correspondant de l'Académie” (Mém. Acad. St. Pétersb., v. 1 (VI sen), Bull. Scient., 4–8, 1830).
Induction‐coefficients for magnetometer‐magnets
Authors: McComb H. E.
Published: February 2008

A special apparatus was designed for the investigation of induction‐coefficients of magnetometer‐magnets by Lamont's method. Maximum accuracy is secured when the vertical distance between magnets is equal to one‐half the horizontal distance. Tests were made over wide ranges of horizontal and vertical distances.
Magnetic work on the Latvian Coast and the Baltic Sea, 1927–1928
Authors: Slaucitajs L.
Published: February 2008

The Baltic Sea is known to be much disturbed magnetically. Measurements made on the coast while giving, of course, only the general picture, indicated some local perturbations. Progress in the magnetic investigation of the Baltic Sea is being made by the survey‐work of the Esthonian non‐magnetic yacht Cecilid. Such measurements by the Cecilie were also made on the coast of Latvia in the years 1927 to 1928.
Ions and electrical currents in the upper atmosphere
Authors: Hulburt E. O.
Published: February 2008

In a paper to be communicated to the American Physical Society it is assumed that the ionisation in the upper atmosphere is caused by the ultraviolet light of the Sun and that the ion‐ and electron‐densities at noon at the equator are those required by the theory of wireless wave‐propagation. From the laws of recombination of the ions and the diffusion and drift of the ions in the Earth's magnetic and gravitational fields, the distribution of the ions and electrons over the Earth is worked out. The distribution turns out to be that required by the diamagnetic theory of the solar diurnal‐variation of the Earth's magnetism (Gunn, Phys. Rev., v. 32, 1928 (133); Terr. Mag., v. 34, 1929 (17)). The gravitational drift‐currents are found to flow mainly along the parallels of latitude in the following way: On the daylight hemisphere (1) a current‐sheet flowing eastward in the levels above 150 km, which at the sunrise and sunset longitudes divides into two sheets; (2) one of these flows westward on the day side of the Earth underneath (1) in the levels below 150 km, and (3) the other sheet continues eastward in the upper levels around on the night side of the Earth.
Huancayo Magnetic Observatory, March to April, 1929
Authors: Ledig Paul G.
Published: February 2008

March 11, 1929—A severe magnetic storm began at 13h 53m on March 11 with a sharp decrease of 18γ in horizontal intensity and an immediate increase of 193γ the following four minutes. The declination and vertical‐intensity traces also showed distinct increases within the next three or four minutes. The storm was distinguished by rapid but moderate fluctuations in horizontal intensity during the daily maxima of March 11 and 12, and by subnormal horizontal intensities with much slower changes during the rest of the time. Declination and vertical‐intensity traces showed only moderate fluctuations during the storm, which ended at about 5h on March 13, at which time the horizontal‐intensity trace became practically normal again.
James Percy Ault, 1881–1929
Authors: Harradon H. D.
Published: February 2008

The Department of Terrestrial Magnetism of the Carnegie Institution of Washington has suffered an irreparable loss in the untimely death of Captain J. P. Ault, chief of its Section of Ocean Work and Commander of the non‐magnetic ship Carnegie. On November 29, 1929, while a supply of gasoline was being taken on board in the harbor of Apia, Western Samoa, an explosion took place as a result of which Captain Ault lost his life, and the vessel, together with all its instrumental equipment, was destroyed. Thus the extensive program of the seventh cruise of the Carnegie, which up to that time, under the able direction of Captain Ault, had yielded most valuable contributions to our knowledge of the oceans, was brought to an abrupt termination.

Captain Ault was born on October 29, 1881, at Olathe, Kansas, and educated at Baker University where he received an A.B. degree in 1904. Even while studying in the University he took an active interest in the work of the then newly established magnetic observatory of the United States Coast and Geodetic Survey at Baldwin, Kansas, where he served as observatory assistant from January 1901 to June 1904. In the latter month he was appointed as magnetic observer in the Department of Terrestrial Magnetism and the next year, after receiving the necessary preliminary training on the U.S. Coast Survey vessel Bache on a cruise from Baltimore to Panama, he was assigned to scientific work on the magnetic‐survey vessel Galilee where he remained until November 1906. During the next two years he was engaged at the office of the Department in Washington and on magnetic field work in Mexico and Canada, carrying out in the latter country a difficult exploratory trip in the course of which he secured magnetic results in territory where none had previously been obtained. In order to fit himself more thoroughly for a scientific career he next pursued postgraduate studies at Columbia University from which institution he received an A.M. degree in 1909. In view of his skill and experience gained on earlier expeditions, he was again, in 1912, placed in charge of field parties in Peru, Bolivia, and Chile, for the purpose of training new observers in making magnetic determinations under field conditions. In the course of the ever‐broadening scope of the Department's activities, special investigations were early instituted for determining possible variations in the Earth's magnetic and electric fields due to a total solar eclipse, and in the case of the solar eclipse of September 10, 1923, at Point Loma, California, and that of January 24, 1925, at Greenport, Long Island, it was Captain Ault who was selected to assume the responsibility of directing these delicate measurements.
Auroral observations, radio reception, and magnetic conditions at the Sitka Magnetic Observatory, July 1928 to June 1929
Authors: Ulrich Franklin P.
Published: February 2008

This report is a continuation of the reports, begun in 1923, of the investigation concerning the relation between aurora and the Earth's magnetic field, and the effect of the Earth's magnetic field upon radio reception.

This year the work is divided into three parts (a) The observation of aurora at the Sitka Magnetic Observatory with a comparison of the Earth's magnetic field; (b) a record of daily radio reception with a comparison of the Earth's magnetic field; and (c) a log of auroral frequency.
Note on the computation of the moment of inertia of a magnet and its suspension
Authors: Duvall C. R.
Published: February 2008

A method of computation of the moment of inertia of a magnetometer‐magnet is developed which gives a considerable saving of time over the method generally used. The reduction‐formula is transformed so that the whole computation may be made by differential method.
A theory of meteors
Authors: Maris H. B.
Published: February 2008

High Speed Molecular Impacts—The energy of impact between a molecule of atmospheric nitrogen and a meteor moving 4×106 em per sec is sufficient to vaporize 56 molecules of iron from the solid state to a gas at a temperature of 3000°K, or is equal to the energy of an electron dropped through about 200 volts. It is assumed that where such energies are involved, we should expect the impact to result in a miniature explosion, which would drive from 10 to 100 molecules out of the main mass of the meteor.

Total Energy of a Meteor—The energy of the average meteor is observed to be dissipated within roughly 1.5 seconds after entering the upper atmosphere. It is shown that the resistance of the air to the solid mass of the meteor can account for only about one per cent of the total energy loss, and that radiation from the surface of the meteor can account for less than one per cent of the total radiation. It is concluded that most of the energy of the meteor is dissipated and changed to radiant energy by the high energy atoms and molecules which escape from the meteor and communicate their energy to the air by collision with air molecules.

Development of the trail—The meteor flashes into view when the energy of molecules escaping from it is sufficient to support the radiation of the trail. Impacts between air‐molecules in the path of the meteor and escaping molecules prevent an increase in brilliancy as the meteor moves from the height of appearance to denser strata of air. At a height of about 60 to 80 km a compressed air‐cap is formed in front of the meteor which prevents further direct impacts between stationary air‐molecules and the meteor.
On the theory of solar corona
Authors: Hulburt E. O.
Published: February 2008

The outer atmosphere of the Sun is assumed to be composed mainly of charged particles, which are actuated by gravitation, radiation‐pressure, and the magnetic field of the Sun. By distillation along the lines of magnetic force the particles collect in the lower latitudes of the solar outer atmosphere and by their diamagnetism and drift‐currents reduce the magnetic field approximately to zero in this region, leaving a stray field at the poles. Thus the coronal streamers, prominent during sun‐spot minima, are regarded as owing their form to the magnetic field of the Sun. Whereas the wide‐spreading structureless coronal luminosity extending out from the lower latitudes is due to an accumulation of ionization which reduces the magnetic field to a low value and permits the radiation to blow the particles out to great distances.
Huancayo Magnetic Observatory, May to August, 1929
Authors: Ledig Paul G.
Published: February 2008

July 10, 1929—Beginning with a sudden increase of 64γ in two minutes in horizontal intensity at 11h35m and a sharp increase in declination at about the same time, there was a short magnetic storm on July 10, which was characterized chiefly by large rapid fluctuations in horizontal intensity, and by marked disturbances in declination and vertical intensity. The disturbance moderated at about 19h and ended before 23h.
Preliminary results of ocean magnetic observations on the Carnegie from Hawaii to Samoa, October to November, 1929
Authors: Ault J. P.
Published: February 2008

Leaving Honolulu, October 2, under tow, sail was set in a fair wind when three miles off the entrance to the harbor. For five days winds were fairly strong and favorable, from the east and northeast. On October 7 the trade‐wind went light and on the eighth it shifted to the southwest. The wind continued from the westward until October 18, when it shifted to the east and with only slight interruptions remained in that quarter until Pago Pago was reached.
The last cruise of the Carnegie
Authors: Fleming J. A.
Published: February 2008

On the afternoon of November 29, 1929, there ended tragically the last of the seven great adventures represented by the world‐cruises of the non‐magnetic ship Carnegie of the Carnegie Institution of Washington. Her design, construction, and instrumental appliances were based upon the work of the Institution's Department of Terrestrial Magnetism done on the chartered brigantine Galilee from 1905 to 1908 during three cruises (68,834 nautical miles in 897 days actually at sea) in the Pacific Ocean. Since her launching in 1909 she had successfully completed during 1909 to 1921 in six cruises the first magnetic distribution‐survey of that accuracy required for theoretical discussions and the first atmospheric‐electric survey of the oceans between latitude 80° north to 61° south. In this work she had traversed 252,702 nautical miles in 3,267 days actually at sea.1
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, November 1929 to January 1930
Authors: Nicholson Seth B.
Published: February 2008

For the investigation of the relationship between solar phenomena and certain terrestrial phenomena, it is important to have simple character‐figures to denote the daily intensity of the various phenomena of the Sun's surface. In the tabulation of. provisional character‐figures for the Mount Wilson Observatory the figures assigned are in accordance with those in the bulletin for character‐figures of .solar phenomena published by the International Astronomical Union. The figures for bright hydrogen‐flocculi, calcium‐flocculi, and dark hydrogen‐flocculi are assigned on a scale 0 to 5 referring to the area and intensity of the flocculi; thus 0 represents absence or rarity of flocculi and 5 extreme‐abundance and intensity. The numbers are given for the whole disc (column A in table) of the Sun and for a central zonewhichis a circular‐surf ace of a semi‐diameter of the Sun's disc (column B in table).
Cheltenham Magnetic Observatory October to December, 1929
Authors: Hartnell Geo.
Published: February 2008

(Latitude 38° 44′.0 N.; longitude 76° 50′.5 or 5h 07m.4 W, of Gr.]
Final relative sunspot‐numbers for 1928 and 1929
Authors: Brunner W.
Published: February 2008

The following table contains the final relative sunspot‐numbers for 1928 and 1929, for the whole disc of the Sun based on observations made at the Zurich Observatory, supplemented by series furnished by other cooperating observatories for days when no observations were made at Zurich. It will be noticed that the mean for the year 1928 (77.8) shows an increase of 8.8 over that for 1927 (69.0) whereas that for 1929 (65.0) indicates a decrease of 12.8 as compared with 1928.

The figures below give graphical representation of the daily relative sunspot‐numbers for 1928 and 1929, the times being plotted as abscissas and the relative numbers as ordinales. The limits of the successive solar rotations are indicated by vertical arrows in the upper edge of the figures. A preliminary consideration of the observed and smoothed numbers from 1923 to 1930 indicates the epoch of maximum near 1928.5.