bluuebunny/crossref_metadata_2025 huggingface dataset:
Tucson Magnetic Observatory, October to December, 1941
Authors: Nelson J. H.
Published: February 2008

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

October 11–12—A very moderate storm began about 06h GMT, October 11, and continued for approximately twenty‐seven hours. A considerable amount of short‐period activity was superimposed on a few long‐period variations in both D and H. Very little disturbance in Z was noted. Approximate ranges: D, 11′; H, 139 gammas; Z, 30 gammas.
Huancayo Magnetic Observatory, October to December, 1941
Authors: Ledig Paul G.
Published: February 2008

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

October 22—There was a moderate disturbance characterized by small and relatively rapid movements resulting in a number of peaks and bays in H between 13h and 21h GMT, October 22. D and Z were only mildly disturbed.
Final Relative Sunspot‐Numbers for 1941
Authors: Brunner W.
Published: February 2008

Table 1 contains the final sunspot‐numbers for 1941, for the whole disk of the Sun, based on observations made at the Zurich Observatory, supplemented by series furnished by other cooperating observatories for days (indicated by asterisks) on which no observations were possible at Zurich.

Table 2 gives the yearly means of the relative numbers, R, since the last minimum 1933 and the number of days without spots.
American URSI Broadcasts of Cosmic Data, Giving American Magnetic Character‐Figure, CA, for January to March, 1942, Three‐Hour‐Range Indices, K, and Mean K‐Indices, KA, for October, 1941, to March, 1942
Authors: Johnston H. F.
Published: February 2008

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

As set forth in this JOURNAL for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for January to March, 1942, are given in Table 1.
Adjustment of the Horizontal‐Intensity and Declination Variometers at the Magnetic Observatory, Hermanus
Authors: van Wijk A. M.
Published: February 2008

The Committee, which was appointed by the International Association of Terrestrial Magnetism and Electricity at the Stockholm Meeting in 1930 to consider existing and desirable distribution of magnetic and electric observatories, in its report invited attention to a subject which is as important as the establishment of additional observatories. It is that of the maintenance of proper adjustment of instruments, in particular, of variometers.

The magnetic observatory at Hermanus, which was built in 1940, to meet the needs of the African Continent, came into full operation in January, 1941. The variometer‐equipment consists of one set of Askania D‐, H‐, and Z‐variometers and two sets of la Cour D‐, H‐, and Z‐variometers (15 mm/hr and 180 mm/hr).
Cheltenham Magnetic Observatory, January to March, 1942
Authors: Ludy Albert K.
Published: February 2008

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

February 23–24—A moderate disturbance lasting about twenty‐one hours began at 13h 28m GMT, February 23, with a sudden small drop in H, followed by a gradual decrease during the following seventy‐five minutes, the total change being about 110 gammas. Thereafter irregular fluctuations continued until the end of the storm. Between 01h and 03h, February 24, there occurred a bay in west declination, which temporarily decreased about 24′. Another bay of about 20′ in the opposite direction occurred between 07h and 10h, just before the storm ended.
Magnetic Observatory, Hermanus, January to March, 1942
Authors: Ogg A.
Published: February 2008

(Latitude 23° 25′.2 S., longitude 19° 13′.5 or 1h 16m.9 E. of Gr.)

January 2–5—There were disturbances from 12h GMT, January 2, to 06h, January 3. The largest K‐number was 4, for the periods 12h–15h and 15h–18h, January 2 and 00h–03h, January 3. The disturbances began again at 10h, January 3 and continued until 24h, January 5. The greatest K‐number was 4 for the period 18h–21h, January 5.
Oscillations and pulsations recorded during the year 1941, at the magnetic observatory, Hermanus, South Africa
Authors: Ogg A.
Published: February 2008

The oscillations and pulsations, which are discussed in this report, are those which occur on days which are otherwise quiet. The small movements seen on quiet days have been termed “pulsations” by Dr. van Bemmelen [see 1 of “References” at end of paper].

Eschenhagen [2] was the first to investigate the smallest magnetic perturbations seen on magnetic records. These were fairly regular sinusoidal oscillations, which he called elementary waves.
Characteristics of magnetic storminess at Gjöahavn, 1904
Authors: Wasserfall K. F.
Published: February 2008

The present paper attempts an approximate derivation of the storm‐time part of magnetic disturbances at the station Gjöahavn (latitude 68°.6 north, longitude 264°.1 east), in north polar regions. This task is rendered difficult since the data for Gjöahavn extend over only about a year, whereas Moos [see 1 of “References” at end of paper] used data for the years 1882 to 1905, yielding over 300 storms, in effecting a determination of the storm‐time variation in equatorial regions.

In obtaining the storm‐time variation, which is the part of a storm proceeding according to time reckoned from the commencement of the disturbance, it is convenient in the present instance to remove first from selected days of storm the quiet‐day diurnal variation, the disturbance or storminess diurnal variation, and the influences of irregular disturbances or storminess.
Geomagnetic giant pulsations of March 1, 1942
Authors: La Cour D.
Published: February 2008

An intense sudden commencement was registered on the magnetograms of the Observatory of Copenhagen (Rude Skov) March 1, 1942, at 07h26m53s GMT. During the following disturbance—apparently related to the passage of a large sunspot—a giant pulsation was recorded in the afternoon hours (14h‐18h); as is apparent from the attached copies of magnetograms (Figs. 1 and 2), the amplitude and the period of these giant pulsations are abnormal and the details of the movements have been clearly recorded by the quick‐run recorder. It would be interesting to compare the registrations made of this phenomenon at various stations, and I take the liberty of asking that copies of similar registrations at other observatories be sent me.
Sitka Magnetic Observatory April to June, 1942
Authors: Gebhardt Robert E.
Published: February 2008

April 2—A small disturbance began gradually at about 08h GMT and continued until about 14h. A K‐index of 7 was recorded for the disturbance.

April 4—A small magnetic storm began abruptly at 04h 38m GMT, April 4, and continued with large bays and superimposed short‐period vibrations until the close of April 4. K‐indices of 8 were recorded for three consecutive three‐hour intervals.
Tucson Magnetic Observatory April to June, 1942
Authors: Nelson J. H.
Published: February 2008

April 2‐5—A moderate storm began on April 2 at 04h 38m, GMT, with moderate activity, principally long‐period oscillations. At 19h 18m, April 3, the activity increased somewhat; then the storm died out at about 12h, April 5. There were three abrupt changes in H during the course of the storm: One at the beginning when H increased 16 gammas in fourteen minutes; the second at 19h 18m, April 3, when H increased 29 gammas in seven minutes; and the third at 04h 38m, April 4, when H increased 28 gammas in 6 minutes. Ranges: H, 134 gammas; D, 20′; Z, 32 gammas.
Huancayo Magnetic Observatory April to June, 1942
Authors: Ledig Paul G.
Published: February 2008

Although there were several mild disturbances recorded during April, there was no storm showing characteristics sufficiently marked to merit description.

During May and June geomagnetic conditions as recorded at Huancayo were unusually quiet, especially so during May.
Committee on Coordination of Cosmic‐ray Investigations
Authors: Fleming J. A.
Published: February 2008

This special Committee (consisting of Dr. Walter S. Adams, Dr. Fred E. Wright, and the author) was appointed in December 1932 by Dr. J. C. Merriam, then President of the Carnegie Institution of Washington, to consider coordination of possible continued support by the Institution of research on cosmic rays. Various conferences of the Committee and consultations with interested investigators who had submitted proposals for research in this field were held. The first report of the Committee was submitted in January 1933 with various memoranda regarding possible procedure and estimates of funds required for the year 1933.

The Committee felt strongly that what may be called the geographical reconnaissance in cosmic‐ray research had yielded profitable results but that the principal need was more precise and continuous series of records at a selected number of stations (6 or 8). It seemed desirable that such stations should be well distributed both as regards latitude and longitude in order that the data obtained continuously and simultaneously at the various points for rather long periods might be subjected, to the most careful analysis from the statistical viewpoint. Thus the observations so far reported indicated features of the phenomena which, while infrequent and while differing materially from the majority of data obtained during short series, represented something definitely real. A correct interpretation of such features could not be expected from short series of observations at different seasons in different localities. Another feature was that of diurnal variation or change from day to night, regarding which available data were not conclusive, and which apparently could be thoroughly studied only through continuous photographic registration at several stations in high altitudes over long periods, supported by shorter series of continuous records at different altitudes in the neighborhood of the selected stations. In addition to continuous records at different altitudes at such fixed stations, it appeared desirable to augment data in the higher atmosphere, such as had been obtained by Regener in pilot‐balloons, by Millikan in airplanes, and by Kolhörster in manned balloons, although it is manifestly impossible to obtain continuous records for any great length of time at fixed altitudes by such means.
An investigation of the disturbance daily variations of magnetic storms at Cape Town (ϕ = 33°.9 S. λ = 18°.5 E. Φ= −32°.7)
Authors: Gotsman B.
Published: February 2008

In a previous paper, the disturbance daily variations for the period 1933–40 were derived by subtracting the five international quiet‐day variations from the five international disturbed‐day variations. In this note, however, the disturbance daily variations of the three elements H, D, and Z have been derived from 65 sudden‐commencement storms distributed throughout the same period.

The H‐ranges of the storms chosen‐exceed 100γ and the international character‐number of each day was greater than 1.5. Also the times of the commencement of these storms were fairly evenly distributed over the 24 hours of the Greenwich day.
American magnetic character‐figure, CA, three‐hour‐range indices, K, and mean K‐indices, KA, for July to September, 1942
Authors: Johnston H. F.
Published: February 2008

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

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

(Latitude 12° 02′.7 S., longitude 76° 20′4 or 5h 01m.4 W. of Gr.)

July 11—This slight disturbance beginning at 00h GMT, July 11, was characterized by a complete absence of the normal daylight maximum in H and by irregular moderate‐size peaks and bays until after 22h. The effects on D and Z were very small. It was followed by two days of somewhat lower values in H.
Magnetic Observatory, Hermanus, July to September, 1942
Authors: Ogg A.
Published: February 2008

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

July 2—At 20h 35m GMT, July 2, small bays with small oscillations or pulsations began to form on all traces.
Tucson Magnetic Observatory October to December, 1942
Authors: Nelson J. H.
Published: February 2008

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

October 2–5—A moderate magnetic storm began at 02h 47m GMT, October 2, with a small but definite increase in H (about 17 gammas). The activity was slight until about 12h, October 2, at which time the disturbance became quite pronounced. The principal activity was over by 12h, October 3, but minor variations in D and H continued until about 14h, October 5. Ranges: D, 16′; H, 141 gammas; Z, 46 gammas.
Archaeologica Geomagnetica—II
Authors: Chapman Sydney
Published: February 2008

The second of this series of translations or reproductions of old classic works on magnetism is, like the first*, a translation, by, H. D. Harradon, of a work reproduced by G. Hellmann in his “Rara Magnetica.”** This is Chapter VIII of Part II of Francisco Falero's treatise “Tratado del Esphera y del arte del marear,” written in Spanish and printed in Seville in A. D. 1535 by Juan Cromberger.

Hellmann, who reproduced also the title‐page of this book, refers to it as the first real treatise on navigation; and in his article on the beginnings of magnetic observation,† he states that though it was printed in 1535, after permission to publish had been granted in 1532, it appears to have been written much earlier, before 1519, when Magellan seems to have taken a copy of it with him on his journey round the world.
Cheltenham Magnetic Observatory, January to March, 1943
Authors: Hershberger John
Published: February 2008

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

January 20–22—A moderate disturbance began with a small bay in each of the three elements at about 06h GMT, January 20, and appeared to have ended by 17h, January 21, except that there was a deep bay in D and H between 00h and 02h, January 22. The highest K‐index recorded during the storm was 6, for the first three‐hour period of January 21.
DER MAGNETISCHE CHARAKTER DES JAHRES 1941
Authors: Bartels Von J.
Published: February 2008

Die Zahl der Observatorien, deren Charakterschätzungen teils unmittelbar, teils durch Vermittlung des Chefs des Sekretariats der Internationalen Meteorologischen Organisation (Dr. Swoboda) verwendet werden konnten, war in Januar und Februar 58, im März 57, im April bis Juni 39, im Juli bis Oktober 33, im Oktober bis Dezember 38. Die stärkste Abnahme dieser Zahl tritt Ende März ein, durch den Ausfall der Meldungen von 16 russischen Observatorien. Wie im Vorjahre1 wurden die Internationalen Charakterzahlen C einfach als Durchschnitt aller verfügbaren Charakterschätzungen abgeleitet. Zwar hätte sich die Unstetigkeit zu Anfang April 1941 dadurch vermeiden lassen, dass man die russischen Schätzungen auch schon für das erste Vierteljahr 1941 ausgelassen hätte; dadurch würde die Unstetigkeit aber nur auf Anfang Januar 1941 vorverlegt, was für den Zweck von C kein Vorteil wäre.
COMMITTEE ON COORDINATION OF COSMIC‐RAY INVESTIGATIONS
Authors: Fleming J. A.
Published: February 2008

This special Committee (consisting of Dr, Walter S. Adams, Dr. Fred E. Wright, and the author) appointed in December, 1932, by Dr. J. C. Merriam, at that time President of the Carnegie Institution of Washington, to consider coordination of possible continued support by the Institution of research on cosmic rays, pursued its activities on a somewhat reduced scale during the year ended June 30, 1943. Although the greater part of the interested personnel was assigned to war‐reasearch problems, some progress was made.

There is only a remote possibility that research on cosmic rays may find application to war‐research problems. It is essential, nevertheless, in view of past experience, that as far as possible continuity of permanent records obtained with cosmic‐ray meters be maintained for future theoretical and statistical investigation. Under the general supervision of the Department of Terrestrial Magnetism the cosmic‐ray meters at Cheltenham Magnetic Observatory of the United States Coast and Geodetic Survey, Huancayo Magnetic Observatory (Peru) of the Carnegie Institution of Washington, Amberley Branch of the Christchurch Observatory (New Zealand), National Astronomical Observatory at Tacubaya (Mexico), and Godhavn Observatory (Greenland) of the Danish Meteorological Institute, were kept in operation.
SOLAR AND MAGNETIC DATA, JULY TO SEPTEMBER, 1943, MOUNT WILSON OBSERVATORY
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

During the third quarter of 1943 the Earth's magnetic field was moderately disturbed. Although disturbances lasting several days occurred, only two were called storms.

At the beginning of the storm of August 8‐9, group No. 7599 was 17° east of the central meridian. During the storm of August 28‐September 1, a small group of spots, 15° south, was observed on August 28 (35° west), 29, and 30 (65° west); no spots were seen on August 31 and September 1.
TUCSON MAGNETIC OBSERVATORY JULY TO SEPTEMER, 1943
Authors: Nelson J. H.
Published: February 2008

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

July 4‐6—Following several hours of slight activity a moderately severe storm began suddenly at 09h 54m GMT, July 4, with an increase of 40 gammas in H. Except for some short‐period activity superimposed on the longer‐period variations, there was no outstanding characteristic of the storm. The major disturbance ended late in the Greenwich day July 6. Ranges: D, 17′.5; H, 143 gammas; Z, 39 gammas.
HUANCAYO MAGNETIC OBSERVATORY JULY TO SEPTEMBER, 1943
Authors: Ledig Paul G.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 76° 20′.4 or 5h 01m.4 W. of Gr.)

August 28‐31—Several days of moderate magnetic disturbance began at about 4.5h GMT, August 28, with irregular changes in the H‐trace which developed to a sharp maximum at 08h and a deep minimum at 10h 12m, with a range of 251 gammas between the two, but no other marked large changes before quieting down again at about 19h. There was only very mild disturbance for two days until the late hours of August 30, when a series of slow deep bays and moderately high peaks began with a minimum at 01h 47m. At about 08h the disturbance quieted down until 11h.5. Thereafter a series of moderate peaks and bays were encountered until about 21h. There was only a slight decrease in H‐values after the storm and D and Z showed mildly marked variations only during the daylight hours of August 28 and 31.
Preliminary Summary, Auroral Observations, Meanook, Canada, December 1, 1932, to June 30, 1933
Authors: Vestine E. H.
Published: February 2008

1—Introduction; site of observations

Visual observations of aurora at Meanook (geographic latitude 54°.6 north and longitude 246°.7 east; geomagnetic latitude 61°.8 north and longitude 301°.0 east) were undertaken at 03h and 05h GMT, from December 1, 1932, to June 30, 1933. Observations at other hours and for other periods of the Second International Polar Year were made as opportunity afforded and were incidental to the regularly scheduled magnetic and meteorological observations. A continuous nightly watch was not maintained because of shortage of personnel. Many observations additional to those scheduled were undertaken, however, and a preliminary short summary is presented here for the use of those interested in the rough indications of the results, obtained for this geographic region.

The Meanook Magnetic Observatory is located on a plateau at the top of a hill some miles in cross‐section, approximately on the height of land separating the Saskatchewan and MacKenzie river‐systems. Northwards from the Observatory the land slopes downward about 120 meters in the 14‐km distance to the Athabasca River. To the east the land slopes off, more gradually at first, about 120 meters to the bottom of the sharply marked Tawatinaw Valley, running approximately north and south. In directions due south and to southwest there are gently rolling hills which obstruct slightly the view of the level horizon before the land again slopes downward over a distance of about 200 km. A shallow valley extends for some km immediately to the west. In directions northwest, north, and around to the southeast the view of the terrain is unobstructed for from 30 to 50 km; in other directions an adequate view of the level horizon is available.
A Theoretical Note on the Magnetic Field of a Circular Sunspot
Authors: Chapman Sydney
Published: February 2008

Summary—Calculations are made of the magnetic field at the sunspot ends of a semicircular electromagnet in the form of half an anchor‐ring: the results are compared with the observations of the magnetic field over sunspots.
An Estimate of the Trend of Solar Activity, 1944–50
Authors: Shapley A. H.
Published: February 2008

Summary—With formulas derived recently by Brunner, the epoch of the coming minimum and the succeeding maximum of solar activity as described by relative sunspot‐numbers is estimated as 1944.9 and 1949.6, respectively. The height of maximum is estimated at 80 as compared with 119 for the maximum of 1937.4. Curves are given showing how the above epochs may be expected to vary with the height of maximum and showing observed and predicted sunspot‐activity.
Five International Quiet and Disturbed days for July to December, 1943
Authors: Johnston H. F.
Published: February 2008

Reports of geomagnetic activity for the second half of 1943 have been received from a sufficient number of observatories so that the international quiet and disturbed days can be selected in accordance with the method outlined on pages 219–227 in the December 1943 issue of this JOURNAL. The selection is based on the reports of magnetic character on a scale of 0, 1, and 2 from 35 observatories and of K‐indices from 23 observatories.
Extracts on Magnetic Observations from Log‐Book of João de CastroASTRO, 1538–1539 and 1541
Authors: de Sampaio Ferraz J.
Published: February 2008

Lisbon to Goa, 1538

At dawn, on Saturday, April 13, we saw Palma, which is one of the Canary Islands, hastening to set up the dial‐plate and shadow‐instrument [1]a, a gift from the very excellent Prince, the Infante Dom Luiz, moved by the intense desire to ascertain two things: First, if on this island the needles varied or not [2], for many pilots usually found that in this place and meridian the needles sought the true pole of the Earth [3]; second, if the rule established by Doctor Pedro Nunes was true and accurate, that at every hour of the day in which shadows are obtainable, the altitude of the pole can be determined [4]. With which instrument were made the following observations, with no wind, so that the ship could not be steered all day.

First observation before noon

The Sun being in altitude 57°, the style cast its shadow at 71°, reckoning from north to west.
Cheltenham Magnetic Observatory, April to June, 1944
Authors: Hershberger John
Published: February 2008

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

April 1–3—A disturbance, which at first seemed insignificant, began near 18h GMT, April 1. At about 06h, April 2, the disturbance became more violent than any recorded here in some time. After 13h the storm again was of only moderate severity until it ended at about 09h, April 3. Two K‐indices of 7 were recorded during the most violent part of the storm; also an index of 6 for the first three‐hour period of April 3.
Tucson Magnetic Observatory, April to June, 1944
Authors: Nelson J. H.
Published: February 2008

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

April 1–3—A severe storm began suddenly at 23h 25m GMT, April. 1, with an increase in H of 22 gammas in about four minutes. Large‐amplitude swings in D and H, accompanied by some activity in Z, occurred during the 8‐hour period beginning at 05h, April 2. This was followed by rapid small‐amplitude variations for about sixteen hours, the storm ending about 08h, April 3. Ranges: D, 28′; H, 165 gammas; Z, 50 gammas.
Apia Magnetic Observatory, April to June, 1944
Authors: Sapsford H. Bruce
Published: February 2008

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

April 1–2—This storm began at 23h 31m GMT, April 1, and continued until 23h 50m, April 2. The maximum in H occurred at the beginning of the storm after which it decreased with fluctuations to a minimum at 08h 46m, April 2. Thereafter H increased with fluctuations until the end of the storm. Vertical intensity was disturbed over the whole period with a minimum at 08h 21m and a maximum at 14h 03m, April 2. Declination was only slightly disturbed during the period of the storm. Ranges3 H, 240 gammas; Z, 50 gammas.
Magnetic Observatory, Hermanus, January to March, 1944
Authors: Ogg A.
Published: February 2008

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

January 1—There were disturbances from 09h to 21h GMT, January 1. There was a K‐index of 5 for the fifth three‐hour period.
Committee on Coordination of Cosmic‐Ray Investigations
Authors: Fleming J. A.
Published: February 2008

This Committee (consisting of Walter S. Adams, J. A. Fleming, and Fred E. Wright) appointed in December, 1932, by Dr. J. C. Merriam, at that time President of the Carnegie Institution of Washington, to consider coordination of continued support by the Carnegie Institution of Washington of research on cosmic rays, continued its activities on a somewhat reduced scale during the year ended June 30, 1944. Despite the assignment of the interested personnel to war‐research problems, good progress was made by several of the groups with which the Institution has cooperated.

The operation of cosmic‐ray meters at Cheltenham, Huancayo, Teoloyucan, Christchurch, and Godhavn was maintained, almost without interruption by the collaborating agencies. The supplying of recording paper, replacement of batteries and parts, and filing and copying of records to make them promptly available for any current and future use were effected by the Department of Terrestrial Magnetism.
Mean K‐Indices from Twenty‐Seven Magnetic Observatories and Preliminary International Character‐Figures for 1943
Authors: Johnston H. F.
Published: February 2008

K‐indices have been received at the Department of Terrestrial Magnetism from 30 magnetic observatories for the year 1943. Owing to difficulties of communication or stress of other scientific activities due to the world conflict, the records are not complete from all. Those contributing were, in order of geomagnetic latitude: Godhavn; Ivigtut; College; Lerwick; Dombås; Meanook; Sitka; Eskdalemuir; Rude Skov; Agincourt; Witteveen; Abinger; Srednikan; Yakutsk; Cheltenham; Zaimishche; Vyssokaya Dubrava; Zuy; San Fernando; Tucson; Dusheti; Tashkent (Keles); San Juan; Honolulu; Huancayo; Apia; Hermanus; Watheroo; Toolangi; and Amberley. Newly contributing observatories are two from Greenland, six from the Union of Socialist Soviet Republics and Apia, Western Samoa. The lower limit of a K‐index of 9 is: 300γ at Tashkent (Keles) and Apia; 350γ at Zuy and Dusheti; 550γ at Srednikan, Yakutsk, Zaimishche, and Vyssokaya Dubrava; 2000γ at Godhavn and Ivigtut.
Solar and Magnetic Data, July to September, 1944, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

The magnetic storm of August 2 to 3 occurred during a quiescent period on the Sun. This storm began at 12h GMT, August 2, and ended at 10h, August 3, with a range in H of 185γ. On August 18, a magnetic disturbance occurred from 06h to 13h GMT (=GCT). The range in H was 75γ. No sunspots were observed from July 31 to August 4.
American Magnetic Character‐Figure, CA Three‐Hour‐Range Indices, K, and Mean K‐Indices, KA, for October to December, 1944, and Summary for Year 1944
Authors: Johnston H. F.
Published: February 2008

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

As set forth in this JOURNAL for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for October to December, 1944, are given in Table 1.
Recombination‐Processes in the E‐Layer of the Ionosphere
Authors: Wu Ta‐You
Published: February 2008

It is shown that photo‐ionization of the negative ion of oxygen leads to a low value for the ratio λ of the concentrations of the negative ion and the electron ([O−]/[e]). Hence the observed high value ∼10−8 cm3/sec (compared with the theoretical value ∼10−12 cm3/sec) for the daytime effective recombination‐coefficient a′ in the E‐layer cannot be ascribed to a high value of λ ≃ (102 – 103). It is suggested that in order to explain the observed a′, one abandon the usual assumption that the E‐layer is electrically neutral and postulate instead a preponderance of positive over negative charge so that [O+] or [O2+]≃103[e]. Such a concentration of positive ions is consistent with what is demanded by the Stewart‐Schuster‐Chapman theory for the diurnal variation of terrestrial magnetism. Night‐time conditions in the E‐layer are also discussed. The rise of electron‐density before sunrise is explained.
The General Isogonic Map of the Katanga for Epoch January 1, 1941
Authors: van der Straeten J.
Published: February 2008

The general isogonic map of the Katanga, on the scale of 1:5,000,000, was prepared by using the observations of magnetic declination which were made at most of the triangulation‐points established during 1919 to 1942 by the “Service Géographique et Géologique du Comité Spécial du Katanga.” The observations made by the Lemaire Mission (1899–1909) were also used.

The declination‐measures were made with the magnetic needles with which every theodolite in use by the Service is fitted. These measures were corrected as follows:
Solar and Magnetic Data, October to December, 1944, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

No solar activity was identified with the magnetic storm of October 11.

The great magnetic storm of December 15–18 began when a complex bipolar sunspot‐group, Mount Wilson No. 7695, was 1.6 days past the central meridian, in latitude 22° south. This group, the largest of the new cycle thus far observed, was first seen at the east limb on December 8, having developed on the other side of the disk. Solar flares were observed near It on December 10 and 13.
Sitka Magnetic Observatory, October to December, 1944
Authors: Ludy Carl A.
Published: February 2008

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

December 16—A storm beginning gradually at about 10h GMT, December 16, become violent at 13h. During the 18th hour the storm moderated and ended during the 22nd hour, Kindices of 9 were recorded for two three‐hour periods. The storm was accompanied by an aurora.
Apia Observatory, July to December, 1944
Authors: Sapsford H. Bruce
Published: February 2008

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

August 2–3—The H‐trace became slightly disturbed at about 12h GMT, August 2, and continued so until 02h 09m, August 3, when large fluctuations commenced and continued until 10h 24m, August 3, after which the trace gradually returned to normal. The maximum and minimum in horizontal intensity occurred at 09h 16m and 03h 22m, August 3. Vertical intensity was disturbed over the same period with a minimum at 02h 42m and a maximum at 09h 12m, August 3. There were only very slight disturbances in declination. Ranges: H, 104 gammas; Z, 26 gammas.
Alexander Neckam on the Compass‐Needle
Authors: Bromehead C. N.
Published: February 2008

The four‐hundredth anniversary of William Gilbert's birth has been commemorated by a special meeting of the Royal Society of Medicine on April 5; an address was given by Professor Sydney Chapman on “William Gilbert and the Science of his time,” and has been published in Nature [154, 132–136 (1944)]. His work, “De Magnete,” first published in the year 1600 and made readily accessible by the translation issued for the Gilbert Club in 1900, is well known to all who are interested in the history of the magnetic compass and of terrestrial magnetism. It is regrettable that the “De Naturis Rerum,” by Alexander Neckam, written about 1190, seems to be known to few, since it contains an account of the use of the directional property of a magnet as early as any in Europe. Full credit is however given to Neckam by A. Crichton Mitchell in his “Chapters in the history of terrestrial magnetism” [Terr. Mag., 37, 105–146 (1932)].
Cheltenham Magnetic Observatory, January to March, 1945
Authors: Hershberger John
Published: February 2008

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

January 15—A moderate disturbance began very indefinitely in the beginning hours of January 15, GMT, and ended roughly at the end of that day. A K‐index of 6 was recorded for the seventh three‐hour period of the day.
Watheroo Magnetic Observatory, January to March, 1945
Authors: Parkinson W. C.
Published: February 2008

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

March 12–13— This small disturbance began with a movement which was sudden in H at 09h 46m GMT, March 12, It was a more gradual beginning in D and Z. Irregular fluctuations of generally small magnitude ensued during the next fifteen hours, none of which is worthy of special mention except for a sharp double wave between 00h 40m and 00h 50m on March 13. The range of the double wave was 6′.6 in declination, 20 gammas in H, and 28 gammas in Z. The disturbance ended at 0lh 10m, March 13. Ranges: D, 16′.3; H, 83 gammas; Z, 103 gammas.
Magnetic Observatory, Hermanus, October, 1944, to March, 1945
Authors: Ogg A.
Published: February 2008

(Latitude 34° 25′.2 S., longitude 19° 13′.5 or 1h 16.9m.9 E. of Gr.)

September 30–October 1—A small gradual‐commencement storm, which began about 09h GMT, September 30, continued until 24h, October 1. The maximum K‐indices were 5 for the periods 12h‐15h and 21h‐24h, September 30.
Radio‐echo observations at Tromsö during the solar eclipse on July 9, 1945
Authors: Harang Leiv
Published: February 2008

Summary—The critical frequencies of the ionized layers were determined during the partial eclipse at Tromsö. The maximum obscuration was 92 per cent. For the F1‐ and E‐layers a symmetrical decrease and increase of the critical frequencies and the corresponding maximum electron‐densities were observed during the eclipse. For the F1‐layer the maximum electron‐concentration decreased from 3.47 to 1.48 × 105 electrons/cm3, that is, by 57 per cent. For the E‐layer the maximum electron‐concentration decreased from 2.04 to 1.04 × 105 electrons/cm3, that is, by 49 per cent. For the F2‐layer the commencement of the eclipse was followed by a sudden decrease in the ionization‐curve, the latter having a minimum at about the time of maximum obscuration. But after the eclipse the previous conditions of the F2‐layer seem not to have been restored. From the observations it seems to be evident that the eclipse has an effect on the F2‐layer but that this effect is masked by vertical movements and the slower recombination‐processes.
Solar and magnetic data, July to September, 1945, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

No magnetic storms were recorded at Mount Wilson during July, August, and September. The mean number of sunspot‐groups observed daily in July, 4.4, was the highest monthly mean since the last minimum, which occurred about 1944.2. Sunspot‐groups large enough to be seen without a telescope crossed the Sun's central meridian on July 15.3, August 13.4, and September 23.6, in latitudes 20° south, 23° north, and 19° south, respectively.
American magnetic character‐figure, CA, three‐hour‐range indices, K, and mean K‐indices, KA, for July to September, 1945
Authors: Johnston H. F.
Published: February 2008

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

As set forth in this Journal for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for July to September, 1945, are given in Table 1.
Hermanus Magnetic Observatory July to September, 1945
Authors: Ogg A.
Published: February 2008

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

The disturbances during July and August were mostly of small range. There was one K‐index of range 6 for the three‐hour period 03h‐06h on August 28, and seven K‐indices of range 5 for the periods and dates as follows: 15h‐18h, July 1; 03h‐09h, July 6; 18h‐21h, July 17; 21h‐24h, July 23; 15h‐8h, August 22; and 00h‐03h, August 28.
Solar and magnetic data, October to December, 1945, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

When the magnetic storm of October 23 began, Mount Wilson sunspot‐group No. 7864, latitude 28° south, was 23° west of the central meridian and No. 7867, 29° north, was 14° west. No sunspots were east of the central meridian.

During the storm of December 13 and 14, several small spot‐groups were present on the Sun, but no exceptional activity was observed.
A possible atmospheric solar effect in both geomagnetism and atmospheric electricity
Authors: Wulf Oliver Reynolds
Published: February 2008

In the course of investigations into the relation between geomagnetism and the circulatory motions of the air in the atmosphere [see 1 of “References” at end of paper] the author has called attention to what appears to be a universal‐time dependence at Cheltenham and Tucson of a maximum in the average summer form of the daily variation of the horizontal force. This may be seen in Figure 3 of reference [1] but also in the original source of this figure, namely Figures 9–12 of the publication of the United States Coast and Geodetic Survey, Serial 663, by A. K. Ludy and H. H. Howe, entitled “Magnetism of the Earth.” In Figure 11 Of this latter, the correspondence in universal time of the maximum at Cheltenham and at Tucson, can be seen by displacing the Cheltenham curve two and one‐quarter hours to the left, which places it on Tucson local time.

Indication of a similar thing is contained, furthermore, in the curves for the Honolulu Observatory which are also given in this Figure 11. In all three seasons—winter, equinoctial, and summer—the daily variation at Honolulu is characterized by a midday maximum, but in the change from equinoctial to summer the indication of a subsidiary maximum, in the distortion of the summer curve at about the 10th hour can be clearly seen. The Honolulu curves may be brought approximately to Tucson time by displacing them three hours and ten minutes to the right. If such is done it can be seen that the subsidiary maximum, indicated in the Honolulu summer curve, comes at closely the same Tucson time as do the maxima at Tucson and Cheltenham.
Notes on meeting of Executive Committee of International Council of Scientific Unions
Authors: Fleming J. A.
Published: February 2008

It was agreed that countries that have paid no subscription since 1936 be invited to send delegates to the General Assembly in 1946 but that they should be informed that arrears up to and including 1939 must be paid before their delegates could attend and vote.

It was agreed to start subscriptions from 1946, but to invite the remaining adhering organizations to pay their contributions as from the last date of payment up to and including 1945 and in any case up to and including 1939.
Five international quiet and disturbed days for January to June, 1945
Authors: Scott W. E.
Published: February 2008

Reports of geomagnetic activity for the first six months of 1945 have been received from a sufficient number of magnetic observatories so that the international quiet and disturbed days can be selected in accordance with the method outlined on pages 219–227 in the December 1943 issue of the Journal. The selection is based on the reports of magnetic character on a scale of 0, 1, and 2 from 37 observatories and of K‐indices from 31 observatories.
Watheroo Magnetic Observatory October to December, 1945
Authors: Parkinson W. C.
Published: February 2008

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

October 23–25—A period of moderate disturbance began with a small, but clearly marked, “sudden commencement” at 23h 40m GMT, October 23, the H‐trace showing a sudden increase of 5 gammas. During the ensuing ten hours on October 24 larger movements began, the maximum activity on October 24 being between 10h and 20h. From 01h to 03h, October 25, some rapid, but generally small, fluctuations appeared, and thereafter until 20h, October 25, when the disturbance ended the movements were more leisurely but never of any great amplitude. Ranges: D, 17′.6; H, 137 gammas; Z, 133 gammas.
Two electric generators suitable for the measurement of magnetic intensities and their variations and for other purposes
Authors: Barnett S. J.
Published: February 2008

Introduction

Rotating coils with their terminals connected through commutators or slip rings to electric measuring devices have often been used for measuring or detecting magnetic intensities. For high sensitivity, it is desirable that the rotating coil be wound, of very fine wire, which is a disadvantage, particularly at high speeds; and mechanical and electrical difficulties are often caused by the sliding contacts with the brushes.
The solid angle of the corpuscular solar radiation
Authors: Gnevishev M. N. , Ol A. I.
Published: February 2008

Summary—In this paper an attempt is made to determine the value of the solid angle of the Sun's corpuscular streams. This value has great importance in investigations of the influence of the solar activity on the nature of the active processes on the Sun. The solid angle of the corpuscular solar radiation may be evaluated by using data on: (1) The duration of the magnetic storms; (2) the increase of geomagnetic activity during the equinoctial seasons; (3) the correlation‐coefficients between magnetic activity and area of sunspots in the central zones with different radii; (4) the lag of the 11‐year variations of geomagnetic activity in comparison with the solar index owing to Spörer's law.The researches show that the solid angle of the solar corpuscular streams is from 8° to 9°.
Annual variation at Honolulu
Authors: Omer Guy C.
Published: February 2008

The annual variation of the Earth's field at Honolulu was determined for the X‐, Y‐, and Z‐components. This was a necessary preliminary for a forthcoming study of the local volcanic variations at Honolulu.
A prediction of the next maximum of solar activity
Authors: Waldmeier M.
Published: February 2008

In a recent issue of this Journal A. H. Shapley has given a prognostic of the Sun's activity up to the year 1950, according to which the next maximum will occur in 1949.6 and be characterized by the highest smoothed monthly relative number RM = 80. But as this prognostic is based on the assumption of alternating maxima and moreover makes use, not of the well‐defined minimum, but of the much less accurately observable starting point of a new cycle, it should hardly be able to represent the approaching period of solar activity in a satisfactory manner.
Provisional report of the Secretary, International Association of Terrestrial Magnetism and Electricity for the period 1939–45
Authors: Goldie A. H. R.
Published: February 2008

War history—The Secretary had been due to sail from England for U.S.A. on August 26, 1939. A few days before that date the intended sailing of various British delegates, including the Secretary, was cancelled owing to the imminence of war. All papers for the Washington Assembly had been made ready and had previously been sent on to Washington, and Dr. Joyce acted as Secretary during the meetings.

Executive Committee—Dr, G. van Dijk died during the war. No information is available yet about Professor Tanakadate. The other members, so far as is known, are well.
Solar and magnetic data, January to March, 1946, Mount Wilson Observatory
Authors: Nicholson Seth B. , Sternberg Mulders Elizabeth
Published: February 2008

The magnetic storm of January 3 occurred when only small sunspots were present on the Sun.

The very great magnetic storm of February 7 began when the immense sunspot‐group, Mount Wilson No. 7943, the largest ever recorded (see Pub. Astr. Soc. Pacific, 58, 86–88 and 168, 1946), was 2.0 days past the central meridian, its minimum distance from the center of the solar disk having been 34°. The group consisted of two large spots, each with multiple umbrae, accompanied by several much smaller spots. The over‐all length was 192,000 miles. The area, which changed little during the passage of the group across the Sun, was approximately 5400‐millionths of the Sun's visible hemisphere. As seen projected on the Sun's image, the group covered almost one per cent of the solar disk. The magnetic polarities of the group were normal, but with some complications in the following spot. The umbrae of the preceding spot all had S (negative) polarity; those of the following spot (the largest single spot on record), N (positive) polarity, with the exception of the preceding umbrae and of a small umbra near the following edge. On February 6, brilliant solar flares of intensity 3 were photographed throughout the group from 16h 28m to 18h 38m, GCT. A flare of intensity 3 was observed on February 11 from 00h 00m to 00h 35m.