bluuebunny/crossref_metadata_2025 huggingface dataset:
AMERICAN MAGNETIC CHARACTER‐FIGURE, CA, THREE‐HOUR‐RANGE INDICES, K, AND MEAN K‐INDICES, KA, FOR APRIL TO JUNE, 1943
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 Surveywith 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 April to June, 1943, are given in Table 1.
SITKA MAGNETIC OBSERVATORY APRIL TO JUNE, 1943
Authors: Pinckney Harold W.
Published: February 2008

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

April 10‐11—Beginning at 04h 30m GMT, April 10, slight disturbances of all elements became greater three hours later and again increased in intensity at 11h, but quieted rapidly after 13h and continued with small variations until 03h 28m, April 11, when sudden increases in all elements commenced a nine‐hour storm‐period which was severe between 06h 25m and 07h when a K‐index of 8 was recorded.
CHELTENHAM MAGNETIC OBSERVATORY APRIL TO JUNE, 1943
Authors: Hershberger John
Published: February 2008

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

April 2‐3—A minor disturbance began at 23h 11m GMT, April 2. The principal feature of the disturbance was a relatively deep bay in each of the three elements between 01h and 02h, April 3. A K‐index of 6 was recorded during this period. After 08h the activity was unimportant.
SUMMARY OF THE YEAR'S WORK, TO JUNE 30, 1943, DEPARTMENT OF TERRESTRIAL MAGNETISM, CARNEGIE INSTITUTION OF WASHINGTON
Authors: Fleming J. A.
Published: February 2008

The retarding effect of the war on the progress of geophysical research, indicated in last year's summary, continued to influence progress in geomagnetic and geoelectric research during July 1, 1942, to June 30, 1943. Difficulties of communication between countries have increased and scientific investigations have been largely turned toward developments more nearly connected with the requirements of modern warfare. Many established organizations and observatories, however, have found it possible to maintain at least part, if not all, of their programs so that the loss of continuity in accumulating data is not too serious. The war has, unfortunately, prevented the proposed cruises of the British Admiralty magnetic‐survey vessel Research and the resulting loss of additional observations over the oceans to determine those important changes with the years in the geomagnetic elements is most serious—the more so because of their need in maintaining isomagnetic charts so vital for purposes of navigation, and application in defensive and offensive operations.
AMERICAN MAGNETIC CHARACTER‐FIGURE, CA, THREE‐HOUR‐RANGE INDICES, K, AND MEAN K‐INDICES, KA, FOR JULY TO SEPTEMBER, 1943
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 1943,‐are given in Table 1.
WATHEROO MAGNETIC OBSERVATORY JULY TO SEPTEMBER, 1943
Authors: Parkinson W. C.
Published: February 2008

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

August 7‐9—A small magnetic disturbance began with a sudden commencement in H at 08h 20m GMT, August 7, with small but very rapid oscillations in all three elements. The traces were relatively quiet until 06h 55m, August 8, when larger fluctuations began without any special features except between 15h and 16h, August 8, when large bays and peaks appeared in all three elements. Between 21h, August 8, and 10h, August 9, the value of H was considerably below normal, but the traces then resumed their usual quiet values. Ranges: D, 20′.1; H, 124 gammas; Z, 124 gammas.
Sitka Magnetic Observatory, January to March, 1944
Authors: Pinckney Harold W.
Published: February 2008

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

February 7—A brief period of severe disturbance may be said to have had its commencement at about 05h 30m GMT, February 7, when slight deviations from an unusually calm condition became noticeable. A single large departure between 09h and 11h gave a K‐index of 7 for that period. At 12h large‐amplitude oscillations began which continued for an hour and then became progressively smaller during the succeeding three hours. A K‐index of 9 was recorded during the most severe phase.
Some Early Contributions to the History of Geomagnetism—VIII
Authors: Harradon H. D.
Published: February 2008

We present as the eighth contribution to the early history of geomagnetism extracts from the English version of the “Portuum investigan‐dorum ratio.”1 This work was written by Simon Stevinus (1548–1620), an eminent Dutch mathematician, at the instance of Count Moritz of Nassau, Prince of Orange, Admiral of the Dutch Fleet, who was convinced of the value of a knowledge of the magnetic declination for navigation. It contains the oldest list of values of the magnetic declination (43 stations), emphasizes the great importance of a knowledge of the declination to mariners, and contains an introduction to the determination thereof with the aid of the azimuth‐compass.

The booklet appeared simultaneously in Dutch, Latin, English, and French. P. Plancius, a Calvinist preacher and geographer, is mentioned as the authority for the declination‐values. It appears that he had collected these data for a geographic chart which he is thought to have prepared in 1592 but of which no copy is known to exist.
The Haven‐Finding Art
Authors: Stevinus Simon
Published: February 2008

Although the finding of the variation (whereof hitherto often mention has been made) is known to very many, yet we will in few words show this thing to them which as yet peradventure know not the manner thereof. For here is a question or demand how to find the declination of the magnetical needle. First, therefore, the north point must be sought out, that the pointing of the needle may be compared therewith. The finding thereof in a movable ship has no small affinity with the finding of the north point or meridian line on land, and may thus be shortly dispatched.
The Fiftieth Year of the Journal, 1945
Authors: Fleming J. A.
Published: February 2008

The JOURNAL begins its fiftieth year with this issue. Established in 1896 by the late Dr. Louis A. Bauer, it is unique in that it is the only International journal devoted solely to geomagnetism and its allied subjects of atmospheric electricity, earth‐currents, and aurora.

Its pages give a progressive record over the half‐century of the advance in knowledge of these subjects communicated in contributions from nearly all of their eminent investigators. The JOURNAL, to keep pace with the ever‐widening field, has gradually broadened its scope to include researches involving ionospheric, solar, and cosmic phenomena. During its lifetime the world‐wide magnetic survey on land and sea by the Carnegie Institution of Washington was successfully concluded and the results obtained during the Second International Polar Year were added to the great store of accumulated observational data. All these have made possible fundamental theoretical studies which find expression in various numbers of the JOURNAL along with agenda and decisions at, and results from, International scientific meetings, descriptions of improved instruments and methods as developed from year to year. Thus the JOURNAL constitutes a real source of reference for geomagnetism and geoelectricity during the past 50 years.
A Curious Effect in an Ionization‐Meter
Authors: Gish O. H.
Published: February 2008

While testing some ionization‐meters designed and constructed at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington for use in a project proposed by Dr. ,V. F. Hess [see 1 of “References” at end of paper], it was found by K. L. Sherman that the rate of ion‐formation per cc in these meters was more than three times that measured under similar circumstances with Kolhörster penetrating‐radiation meter No. 5658 made by Günther and Tegetmeyer in 1928 (GT 5658).

Perhaps the most convincing measure, of this contrast is provided by comparing the “Eve's numbers” (K), which were determined for the instruments.
Sitka Magnetic Observatory, January to March, 1945
Authors: Ludy Carl A.
Published: February 2008

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

January 15—A storm, beginning gradually at about 05h GMT, January 15, slowly increased in intensity until about 11h 36m when an abrupt decrease of 295 gammas in H was followed shortly by an equally abrupt increase and broader bays which increased in irregularity until about 19h 45m when the storm terminated abruptly. K‐indices of 7, 7, 6, 7 were recorded during the period.
On the electrical state of the upper atmosphere
Authors: Ferraro V. C. A.
Published: February 2008

(1) According to Ta‐You Wu, photo‐ionization of the negative oxygen‐ions in the E‐layer reduces their density well below that of the electron‐density and, consequently, the high value (10−8 cm3/sec) of the effective coefficient of recombinations, α, cannot be accounted for on the hypothesis of electron‐attachment and detachment. Wu suggests that the high value of α may still be explained if the usual assumption that the ionized layers are electrically neutral to a high degree of approximation is abandoned, and a high preponderance of positive oxygen‐ions O+ or O2+ over electrons, in the ratio of 108:1, postulated. Wu further claims that such a high concentration of positive ions is “consistent with what is demanded by the Stewart‐Schuster‐Chapman theory” for the diurnal variation of S.

The purpose of this note is to show that Wu's hypothesis is untenable, first as the space‐charge required by the dynamo‐theory of the S‐field is exceedingly small, the number of excess charges of one sign over charges of opposite sign being nowhere greater than about 0.1 ion in a column of one cm2 cross‐section drawn vertically in the layer, Secondly, such a large concentration of positive charges in the atmosphere as is postulated by Wu would produce electric fields so large that the atmosphere could not hold together under gravity against the mutual repulsion of its parts.
Cheltenham Magnetic Observatory April to June, 1945
Authors: Hershberger John
Published: February 2008

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

April 1–2—A moderate disturbance began rather definitely at 05h 00m GMT, April 1. For seven hours all three elements were fairly active. Thereafter the activity was limited mostly to short‐period oscillations in D and H. The storm ended at about 03h, April 2. Three K‐indices of 5 were recorded.
Huancayo Magnetic Observatory April to June, 1945
Authors: Ledig Paul G.
Published: February 2008

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

April 11—There was a short magnetic disturbance on April 11 beginning with a short sharp increase in H at 07h 27m GMT, followed by some rapid vibratory movements during the first two hours, but otherwise with only minor changes until 12h 55m. At that time there was a sharp bay followed quickly by a sharp peak and another bay and peak, with the maximum for the day at 14h 41m. There were a couple of low bays during the following night, but the real disturbance was ended by 18h, April 11. The range in H was 196 gammas, and D and Z were only mildly disturbed.
A study of auroral arcs and draperies
Authors: Harang Leiv
Published: February 2008

Summary—By means of parallactic photographs at Tromsö the heights and directions of auroral arcs and the heights of the draperies have been studied. The number of the pairs used is 355 for the arcs and 293 for the draperies. From the height‐statistics it is shown that the heights of arcs and draperies, according to classifications faint, medium, strong, and very strong, show a continuous decrease. For the auroras of medium intensity it is shown that there is definite evidence of a displacement of the height‐curves from ebb‐tide to flood‐tide conditions.

The diurnal variation of the direction of the arcs during 16h to 24h, MET, is demonstrated for Tromsö, and a secular change in the mean directions is demonstrated when compared with Bravais' determinations in Bossekop during 1839–40.
The spherical harmonic analysis of the Earth's magnetic field for the epoch 1945
Authors: Afanasieva V. I.
Published: February 2008

(1) In the year 1944 the world magnetic charts for declination, inclination, and horizontal intensity for the epoch 1945 were prepared by the Institute of Terrestrial Magnetism of USSR. They were based on the corresponding charts of the British Admiralty for 1942.5, USA Hydrographic Office for 1940.5 and as regards the territory of USSR on those of the Institute of Terrestrial Magnetism for 1940.5. Thus, for the first time, the data of general magnetic survey of the USSR comprising more than 23,000 magnetic determinations were used in the world magnetic charts. The new charts proved, as regards USSR, considerably different from all preceding world charts.
International scientific cooperation
Authors: Stratton F. J. M.
Published: February 2008

The gradual easing of restrictions on travel and on the general release of scientific discoveries has made it practicable once more to arrange international meetings of men of science. The General Assembly of the International Council of Scientific Unions will meet in London on July 22–24, 1946 [the last General Assembly of the Council was in London in May 1937; the next General Assembly was to have been held in Copenhagen in 1940, to be preceded by a meeting of the Executive Committee in October 1939, but the outbreak of the war necessitated that both these meetings be canceled]. Meanwhile its Executive Committee has held a meeting [December 4–5, 1945] in London, attended by representatives of most of the International Unions adhering to the Council. [The following members of the Council and guests were present: Dr. H. R. Kruyt of Holland (Vice‐President and President); Dr. J. A. Fleming of U.S.A.; Prof. B. Nemeč of Czechoslovakia; Sir Harold Spencer Jones of Great Britain; Prof. J. E. Proudman of Great Britain; W. D. Lambert of U.S.A.; Prof. E. de Martonne of France; Prof. M. J. Sirks of Holland; Prof. F. J. M. Stratton of Great Britain (General Secretary); Dr. Vranek and Mrs. Malterre of France (representing the International Organization for Intellectual Cooperation); and (during part of the time) Sir Henry Dale, past President of the Royal Society of Great Britain; Dr. A. V. Hill, Foreign Secretary of the Royal Society of Great Britain; Prof. P. M. S. Blackett of Great Britain; Dr. L. H. Lampitt of Great Britain; Prof. R. M. Field of U.S.A.; and Prof. J. M. Burgers of Holland. Apologies for absence were reported for Prof. M. S. Siegbahn of Sweden, Vice‐Président of the Council; Sir Edward Appleton of Great Britain; Commandant Dorsimont of France; Prof. A. Cotton of France; Prof. O. Bergstrand of Sweden; and Prof. F. Verdoorn of Holland, now resident in the U.S.A.]
Sitka Magnetic Observatory October to December, 1945
Authors: Campbell Joel B.
Published: February 2008

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

October 12—A short storm of moderate activity began at about 06h GMT October 12. At 1lh the activity began to increase and during the 13th hour a maximum of disturbance was reached when H decreased about 425 gammas. After 15h the storm gradually subsided; however, short‐period oscillations followed for several hours. K‐indices of 6 and 7 were recorded during the period of the storm.
The application of solar and geomagnetic data to short‐term forecasts of ionospheric conditions
Authors: Shapley A. H.
Published: February 2008

The program for the systematic collection of current solar and geomagnetic data coordinated at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington (DTM CIW), particularly for application to short‐term forecasting of magnetic and ionospheric disturbances, has been in progress since July, 1942. The ways in which recurrence‐tendencies of geomagnetic activity, reports of solar activity, and various solar‐terrestrial relationships are used in preparing the forecasts are described in this report. The forecasts issued by the Interservice Radio Propagation Laboratory (IRPL) in collaboration with DTM CIW are compared with magnetic activity for a 15‐month period and show that the forecasts are satisfactory about 70 per cent of the time. The correlation‐analyses of coronagraphic and spectroheliographic data with magnetic activity show that over a period of two years there was a decided tendency for disturbances to occur when solar regions identified by these observations were east of the central meridian of the Sun. Reductions of solar and geomagnetic data indicate that a minimum in solar activity occurred early in 1944, but that the minimum epoch of geomagnetic activity cannot as yet be defined. Reference is made to the application of visually recording magnetographs developed at DTM CIW.
Final relative sunspot‐numbers for 1945
Authors: Waldmeier M.
Published: February 2008

Table 1 contains the final sunspot‐numbers for 1945 for the whole disk of the Sun, based on observations made at the Zürich Observatory, supplemented by series furnished by other cooperating observatories. Table 2 gives the number of spot‐groups on each day for the year 1945. The yearly mean of the group‐numbers is 3.0. The yearly mean of the relative‐numbers is 33.2, against 9.6 in 1944.
Sitka Magnetic Observatory January to March, 1946
Authors: Campbell Joel B.
Published: February 2008

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

January 3–4—A severe storm began sharply at 07h GMT, January 3. Activity was moderate for the first three hours of the storm; however, at 10h 30m there was a marked increase in activity, resulting in an over‐all change of 149′ in D 1309 gammas in H, and 905 gammas in Z. The storm moderated at about 18h, January 3, and the activity which followed consisted chiefly of low‐amplitude oscillations superposed on small bays. At about 23h this type of activity was replaced with larger‐amplitude oscillations, which continued until the storm gradually died out at about 23h, January 4. K‐indices of 9, 7, and 8 were recorded between 09h and 18h, January 3.
American magnetic character‐figure, CA, three‐hour‐range indices, K, and mean K‐indices, KA, for April to June, 1946
Authors: Scott W. E.
Published: February 2008

Summaries of American URSI broadcasts have appeared regularly in this Journal since the issue for December, 1930.
Sitka Magnetic Observatory April to June, 1946
Authors: Campbell Joel B. , Cleven M. L.
Published: February 2008

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

April 9—A brief period of moderately disturbed conditions began shortly after 09h GMT and died out about 17h of the same day. K‐indices of 6, 7, and 7 were recorded with greatest disturbance occurring during 14h and 15h.
Cheltenham Magnetic Observatory April to June, 1946
Authors: Wiles William E.
Published: February 2008

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

April 15—Following a two‐day period of moderate disturbance in H and D, a storm of moderate intensity began with a disturbance in all three elements between 01h and 02h GMT, April 15, and ended about 2lh, April 15. The disturbance consisted of irregular oscillations of moderate amplitude and was greatest between 01h and 13h; after 13h all three traces began to reassume gradually their normal positions. Four K‐indices of 5 were recorded. Minimum H of 18060 gammas occurred at 12h 28m.
Hermanus Magnetic Observatory April to June, 1946
Authors: van Wijk A. M.
Published: February 2008

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

April 1–4—The minor disturbances recorded on these days were characterized by bays, each of K‐index 3, during the three‐hour periods (GMT) 00h–3h on April 1, 00h–03h on April 2, 21h–24h on April 2, and 21h–24h on April 4.
Records of the ionosphere during the total eclipse in the north of Sweden on July 9, 1945
Authors: Stoffregen W.
Published: February 2008

An expedition was sent from the Institute for High‐Tension Research, University of Uppsala, for ionospheric investigations together with research on thunderstorms and atmospherics during the total eclipse on July 9, 1945. The observations were made at Hörnsjö (latitude = 63°.82 north, longitude = 19°.56 east). The times of first contact, maximum obscuration, and last contact were 13h51m.6, 15h01m.5, and 16h07m.7, respectively. Hörnsjö is situated vertically below the central‐line of the eclipse at about 100‐km height of the E‐region.
Frequency of 12,330 measured heights of aurora from southern Norway in the years 1911–1944
Authors: Störmer Carl
Published: February 2008

(1) Since 1911, I have had at my disposition a network of auroral stations in southern Norway and about 32,000 usable auroral photographs have been taken. Among these are several thousand taken simultaneously from two or more stations to determine the height and situation of the aurora. The results obtained during 1911–22 are described in Geofysiske Publikasjoner [see 1 of “References” at end of paper]. Since 1922 only selected auroras have been measured.
The equilibrium of atmospheric sodium
Authors: Bates David R.
Published: February 2008

Consideration is given to the Na‐Na+ and Na‐NaO equilibrium in the Earth's atmosphere. It is probable that in the region of 100 km the free sodium is almost completely ionized and that the concentration of the ions relative to the main atmospheric constituents increases upwards. A possible interpretation to be attached to this is mentioned. It is pointed out that the current theory of the nocturnal emission of the D‐lines is not reconcilable with the measured altitude of the emitting layer.
Reminiscences of Sir Carruthers Beattie and Professor J. T. Morrison
Authors: Ogg A.
Published: February 2008

It is with regret that I have to report the deaths of Sir Carruthers Beattie and Professor J. T. Morrison—pioneers in geomagnetic surveys and investigations in Africa. The former died in September, 1946, and the latter in October, 1944, aged 82. We in Africa are indebted to these two men, not only for magnetic observations throughout Africa so generally known from the Royal Society publications, but also for the stimulus given by them in forwarding educational and scientific progress.

I was very fortunate in knowing both Beattie and Morrison intimately from the time I came to South Africa in 1905 until they died. There was no scientist for whom I had more respect than for Morrison. He did not appear in the public eye so much as Beattie did. For many years Beattie was chiefly interested in university development in South Africa. Such work appealed more to the general public than pure scientific research.
Cosmic‐ray research in B‐29 laboratory determines nature of secondary particles
Authors: Grosvenor Gilbert
Published: February 2008

Research in a B‐29 “flying laboratory” has contributed to knowledge of cosmic radiation by proving that a large proportion of mesotrons—a part of the rays in the Earth's atmosphere—are produced by electrically‐charged particles.

The National Geographic Society, the Bartol Research Foundation, and the Army Air Forces joined last summer in an extensive series of B‐29 flights to record the number of mesotrons in the air [see Terr. Mag., 51, 303–304 (1946)]. Tests were made at altitudes ranging from one to more than six miles between southern Canada and the magnetic equator over northern Chile.
Cheltenham Magnetic Observatory October to December, 1946
Authors: Wiles William E.
Published: February 2008

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

October 26–28—A mild magnetic storm began between 21h and 22h GMT, October 26, and continued until about 01h, October 28. All three elements were disturbed, the greater disturbance occurring within the first twelve hours and consisting of irregular oscillations of moderate amplitude. For the remainder of the storm some short‐period motion and minor irregular oscillations appeared. Five K‐indices of 5 and four of 4 were recorded.
Hermanus Magnetic Observatory October to December, 1946
Authors: van Wijk A. M.
Published: February 2008

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

October 8–9—A disturbance of very moderate intensity began gradually at 22h GMT, October 8, and continued until about 24h, October 9. Small, sharp oscillations during the first five three‐hour periods of October 9 were followed by large, shallow bays between 22h and 24h.
Historical notes on the deviation of the compass
Authors: May W. E.
Published: February 2008

Few historians of the magnetic compass carry their story beyond the period of the birth of ocean navigation. To those interested in this fascinating instrument there are, however, many interesting lines of enquiry to be traced in the centuries which followed. These notes are the result of an attempt to investigate the beginnings of just one branch of progress.

During the Sixteenth, Seventeenth, and Eighteenth Centuries, when there were many who tried to solve the problem of finding the longitude at sea, one of the favorite methods proposed was the use of the variation of the compass. Of those who proposed this method one of the last was Ralph Walker, a resident of Jamaica, who, in the year 1793, traveled to England to lay his proposals before the Board of Longitude. It is not intended here to discuss his variation theory but to point out that, in addition to producing this theory, he designed a compass to enable the variation to be observed with greater accuracy at sea. This compass was sent for trial in H. M. Ships Invincible, Glory, and Lynx and it was this trial in the Glory which introduced her master, Murdo Downie, to fame among those who have written on the magnetic compass. In his report on Walker's compass Downie wrote [see 1 of “Authorities quoted” at end of paper]:

“It appears, that the variation observed at one view by Walker's compass, and that observed by the ship's compass by the bearing and altitudes, were generally very near the same. But it is evident, that the variations given by both compasses at different times and situations disagree very much: Whether any part of this disagreement may be owing to the time of the day the variations were taken, I cannot take on me to determine; but I am pretty well convinced, that the quantity and vicinity of iron in most ships has an effect in attracting the needle; for it is found by experience, that the needle will not always point in the same direction when placed in different parts of the ship: Also it is rarely found, that two ships steeling the same course by their respective compasses will go exactly parallel to each other; yet these compasses, when compared on board the same ship, will agree exactly.”
Tucson Magnetic Observatory January to March, 1947
Authors: Nelson J. H.
Published: February 2008

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

January 16—A moderate storm of only about 20 hours' duration began suddenly at 03h 30m GMT, January 16, with increases of 35 gammas in H and 4′ in eastward D. The greatest disturbance in D and minimum values of H occurred between 15h and 21h. Ranges: H, 135 gammas; D, 18′.
Huancayo Magnetic Observatory October, 1946, to March, 1947
Authors: Ledig Paul G.
Published: February 2008

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

October 20—There was mild magnetic disturbance on October 20, characterized chiefly by having a “sudden commencement” in H at 03h 08m GMT, two small peaks between 15h and 16h, and a small peak and bay near 19h D and Z were only very slightly disturbed by small movements.
Untersuchungen über die 27‐tägige Welle der kosmischen Strahlung
Authors: Gheri Von H. , Steinmaurer R.
Published: February 2008

Zusammenfassung—Die Untersuchung der harten Komponente der kosmischen Strahlung (kS) während der Sonnenrotationen Nr. 1410–1448 Bartelsscher Zählung nach modernen Methoden der Periodenforschung zeigt das Vorhandensein einer persistenten Welle der kS, deren Amplitude mit der von Vallarta berechneten im wesentlichen übereinstimmt. Die Welle tritt in Zeiten sehr starker Sonnentätigkeit hinter Störungen zurück, die mit dem Passieren von grösseren Fleckengmppen durch den Zentralmeridian der Sonne und mit magnetischen Stürmen parallel gehen.
Facilities provided by the Kensington Magnetic Laboratory
Authors: Ramsay B. P. , Yost F. L.
Published: February 2008

(I) Introduction

During World War II a number of educational and scientific institutions entered into contracts to cooperate with the Naval 0rdnance Laboratory (NOL), and contributed in large measure to the success of NOL activities. Contract NOrd‐392 between the Bureau of Ordnance, Navy Department, and the Carnegie Institution of Washington (CIW) stipulated, among other things, that the Department of Terrestrial Magnetism (DTM CIW) provide and operate certain facilities for NOL.

Under the directorship of Dr. John A. Fleming, DTM CIW operated these facilities, which were known as the Kensington Magnetic Laboratory (KML), from March, 1943, to July, 1946. These facilities were housed in frame buildings, such as those shown by Figure 1. The buildings were erected at Kensington, Maryland, under terms of the contract. Six additional buildings of the same general type were provided by NOL at various locations in Maryland, North Carolina, New York, and the District of Columbia. The specifications for these buildings required that the materials used be nonmagnetic and nonmetallic so far as possible. Copper nails and brass screws were employed, copper gutters were specified, and no steel was employed for reinforcing of concrete floors and foundations. The company to which the erection of the Kensington buildings was entrusted submitted a bid “for the construction of a nonmagnetic laboratory”.
Critical survey of recent theoretical work on the ionosphere
Authors: Pande A.
Published: February 2008

Introduction

In recent years a number of theoretical papers have been published on the ionosphere by workers all over the world. From time to time reviews of the theoretical, as well as practical, works have been written by eminent workers [see 1, 2, 3, 4 of “References” at end of paper] in the form of reports. After a study of these papers one finds a certain number of inconsistencies in the various results and assumptions. The purpose of this article is to point out these facts in detail in the form of a review and draw the attention of the workers in this field for solving some of the fundamental problems without which the theoretical work is much handicapped at the present stage.
Provisional sunspot‐numbers for April to June, 1947
Authors: Waldmeier M.
Published: February 2008

(Dependent alone on observation at Zurich Observatory; see notes on page 398)
Cheltenham Magnetic Observatory April to June, 1947
Authors: Wiles William E.
Published: February 2008

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

April 8—A minor disturbance began with a sudden commencement in all three elements at 21h 49m GMT, April 8. H suddenly decreased 50 gammas and then increased 148 gammas, both changes taking place in about two minutes. Irregular oscillations of moderate amplitude appeared in all three elements. The disturbance subsided by 14h. Two K‐indices of 6 and two of 5 were recorded.
Tucson Magnetic Observatory April to June, 1947
Authors: Nelson J. H.
Published: February 2008

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

April 8–9—A storm of only about eighteen hours' duration began suddenly at 21h 50m GMT, April 8, with an increase of about 55 gammas in H and corresponding changes in D and Z. Except for the magnitude of the initial displacement of the traces, the storm‐intensity was quite moderate, with no unusual characteristics. Ranges: H, 131 gammas; D, 13′.
Zô‐Sè Observatory April to June, 1947
Authors: Burgaud M.
Published: February 2008

(Latitude 31° 05′.8 N., longitude 121° 11′.2 or 8h 04m 45s E. of Gr.)

April 3—A minor disturbance began with small abrupt beginning of 15 gammas at 23h 02m GMT. A small solar effect was noted a few hours before.
Watheroo Magnetic Observatory April to June, 1947
Authors: Wood F. W.
Published: February 2008

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

April 8–10—A moderate disturbance commenced suddenly at 21h 49m 30s GMT, April 8. H increased by 30 gammas in less than a minute and then decreased by 22 gammas in the following two minutes, D swung west by 2′ and then 4′ east by 21h 52m. Z increased by 13 gammas and then decreased by 40 gammas in the same time. The movements in all three elements were fairly rapid but not of very great amplitude, and these continued until 16h, April 9, with only a slight depression in H. For the following sixteen hours the elements were somewhat unsteady and the storm can be considered as ending at 08h, April 10, Ranges: D, 20'; H, 120 gammas; Z, 79 gammas.
Solar and magnetic data, April to September, 1947, Mount Wilson Observatory
Authors: Nicholson Seth B.
Published: February 2008

During April (and also March) the Earth's magnetic field was remarkably calm for an equinoctial month in which very large spots were present on the Sun. Although the huge complex bipolar group, No, 8478, which crossed the solar disk from March 30 to April 14, covered a large area and had complex magnetic fields, it produced only a few flares, all of those observed at Mount Wilson being small. This group, a return of the large spot of March, was the largest ever recorded, even surpassing the great group of February, 1946.

The magnetic storm of April 8–9 occurred when the great group was 1.8
Preliminary report on the magnetic results of a journey to Sikkim and Southern Tibet
Authors: Wienert K.
Published: February 2008

Summary—The main result is a table giving declination, horizontal intensity, and dip for 55 stations in Sikkim and Southern Tibet, reduced to the epoch 1939.0. The data were obtained by the author on the Schaefer Expedition in 1938–39. Details are given on the instruments used, and the manner of reduction. Linear formulas for a smoothed normal field in the area are derived for D, H, I, and Z. Numerous observations of vertical intensity with an Askania field‐balance are used for a preliminary description of local anomalies.
Sitka Magnetic Observatory July to September, 1947
Authors: Campbell Joel B.
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 01.m3 W. of Gr.)

July 17–23—Climaxing a short period of very quiet magnetic conditions a fairly severe storm began abruptly at 17h 50m GMT, July 17. During the first fourteen hours activity was limited to short‐period, low‐amplitude oscillations; however, at about 08h, July 18, this activity was replaced by rather deep bays of short duration. Between 10h and 13h a very deep bay occurred in H, which gave a K‐index of 8; however, the most violent activity of the storm took place during the fourteenth hour of July 18 when there was recorded short‐period, large‐amplitude oscillations producing a K‐index of 8. The intensity of the storm began to diminish at about 18h, July 18, but moderately disturbed conditions continued until about 18h, July 20. During the following three days only slight disturbances occurred but at about 06h, July 23, activity began to increase. For the period 09h‐12h, July 23, a K‐index of 7 was recorded. The storm may be said to have ended at 12h, July 23, but lesser disturbances were recorded for several days following.
Tucson Magnetic Observatory July to September, 1947
Authors: Nelson J. H.
Published: February 2008

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

July 17–20—A sudden increase of 18 γ in H beginning at 10h 39m GMT, July 17, probably was the beginning of a moderately severe storm, although the six and one‐half hours immediately following the sudden commencement were quiet. Rapid changes in D and H were in evidence during the four hours beginning at 17h 48m, July 17. The balance of the storm was characterized only by moderately rough magnetic weather, ending about 16h, July 20. Ranges: D, 23′; H, 193 γ; Z, 91 γ.
Account of the Antipolo Magnetic Observatory
Authors: Repetti W. C.
Published: February 2008

Magnetic work was carried on in the grounds of the Manila Observatory from 1888 to 1904. The installation of an electric street‐railway system in the latter year set up magnetic disturbances which rendered the station useless. An isolated location in the country had to be found and attention was first turned to Baguio, but tests proved this to be unsatisfactory and finally a site was found near the town of Antipolo. This is 16 miles by road east of Manila with an elevation of 710 feet above sea level.
Cheltenham K‐indices for January to March, 1948
Authors: Gebhardt Robert E.
Published: February 2008

In continuation of data on geomagnetic activity at the Cheltenham Magnetic Observatory [see Terr, Mag., 52, 403–409 and 522 (1947)], the K‐indices for January to March, 1948, as determined from the photographic records, are given in Table 1.
Cheltenham K‐indices for April to June, 1948
Authors: Ledig Paul G.
Published: February 2008

In continuation of data on geomagnetic activity at the Cheltenham Magnetic Observatory [see Terr. Mag., 52, 403–409 and 522 (1947), and 53, 166–167 (1948)] the K‐indices for April to June, 1948, as determined from the photographic records, are given in Table 1.
A note on the relationship between the horizontal components of Dm and Dst
Authors: Cynk B.
Published: February 2008

Introduction

By DmiH is designated the difference obtained by subtracting the daily mean value of horizontal magnetic intensity, H, on five international quiet days from the corresponding value on five international disturbed days in each month. This difference represents in average a certain storm‐time effect of 5, or less, strongest disturbances occurring in each month, but it lacks an exact physical meaning. It might be only said that DmiH is a result of the storm‐time changes of H being of a form similar to that expressed by the curves given by Chapman as the average effects of 40 moderate magnetic storms [see p. 276 and Fig. 4 of 1 of “References” at end of paper], because a local‐time effect and that of an irregular part of storms included are removed in DmiH by averaging. Let Chapman's curves be designated by fcsH(t) and the storm‐time changes, if referred to the storms occurring on international disturbed days, by fisH(t). DmiH is somewhat associated with fisH(t) but it is not quite clear what relation DmiH exists to any element defined on the basis of fisH(t), which is derived from the same storms as DmiH.
K‐indices and sudden commencements, April to June, 1948, at Abinger
Authors: Jones H. Spencer
Published: February 2008

I enclose the lists of K‐indices of geomagnetic activity and of sudden‐commencement phenomena at Abinger for April to June, 1948, in Tables 1 and 2.
Selected days, preliminary mean K‐indices and C‐numbers for first quarter, 1948
Authors: Johnston H. F.
Published: February 2008

The table (page 320) gives mean K‐indices from the reports from 23 observatories and character‐figures, C, from twenty‐eight. The quiet and disturbed days have been selected by the method outlined on pages 219–227 of the December, 1943, issue of this Journal, which is preferential selection based upon the C‐numbers, sums of the eight daily mean K‐indices, the greatest daily K‐index, and the sums of the squares of the eight daily mean K‐indices.
Ionospheric effects noted during dawn observations on solar noise
Authors: Payne‐Scott R. , McCready L. L.
Published: February 2008

The possibility of using extra‐terrestrial sources of radio waves to investigate the structure of the ionosphere has been discussed at some length in a recent paper by Bailey [see 1 of "References" at end of paper]. The measuring technique he suggests is based on that devised in this Laboratory [2] to determine the location on the Sun of the source of "solar noise". We suggest here a slight modification better suited to such investigations and give some results obtained both at relatively quiet periods and at periods of sunspot‐activity.

Our original technique [2] consists briefly in receiving simultaneously for about an hour after sunrise the direct radiation from the Sun and that reflected from the sea's surface about 300 feet below the receiving point. From the resulting interference‐pattern one can determine the apparent elevation of the source at any time. By correcting for atmospheric refraction the actual elevation of the source is found, as long as there is no further source of refraction. At the frequency originally used, 200 Mc/s, ionospheric refraction is normally only a few minutes of arc and can be ignored, so that the true position of the source can be found.
The Geophysical Observatory, University of Alaska
Authors: Bunnell Charles E. , Seaton S. L.
Published: February 2008

The University of Alaska has been engaged since 1929 in arctic research embracing many of the departments of natural science and in particular the field of geophysics. The term geophysics is taken to mean earth physics generally. The University is located at latitude 65° north and longitude 148° west, near Fairbanks, Alaska.

In the earlier years this research took the form of isolated projects and of specialized individual studies. Early in 1941 the Carnegie Institution of Washington, in co‐operation with the University of Alaska, instituted a broad attack on arctic physical problems embracing studies of the ionosphere, of long‐distance, radio‐wave propagation, measurements of zenith auroral intensity, continuous determinations of the Earth's magnetic field, and a continuation of seismological studies. This broader program was well in hand when World War II started.
Historical note on the denomination “Geomagnetic tides”
Authors: Schneider Otto
Published: February 2008

Readers working on daily magnetic variations will be interested in the following note quoted from Alexander von Humboldt's “Kosmos”, where the denomination of “magnetic tides”, recently used by Bartels and Johnston appears to have been introduced for the first time.

In note 53 [p. 117, vol. IV], Humboldt mentions a letter to Hansteen, dated Rome, June 22, 1805, and later reproduced in Hansteen's “Magnetismus der Erde” [p. 459, 1819], in which he describes the daily variation of D as producing “four movements of the needle, four magnetic tides, as it were, analogous to the periods of the barometer”.
Cheltenham Magnetic Observatory July to September, 1948
Authors: Ledig Paul G.
Published: February 2008

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

August 7–10, 1948—Following a mild disturbance, which began at 03h 1lm GMT, August 7, with a sudden decrease‐increase in H of 45 gammas and lasted until about 14h, a prolonged and severe magnetic storm began with a sudden commencement in all three elements at 23h 00m on the same day. H decreased 48 gammas and increased 151 gammas in one minute, then decreased gradually, exhibiting irregular oscillations of moderate amplitude until 07h 22m, August 8, when it decreased 238 gammas in twenty‐five minutes, and after this deep bay showed rapid oscillations superimposed on frequent peaks and bays until about 16h, reaching its minimum of 17,991 gammas during this period at 09h 21m. The rapid oscillations continued as H increased irregularly with only one deep bay to its maximum of 18,408 gammas at 21h 22m, August 8. After another hour, activity diminished to a mostly mild disturbance except for two deep bays between 06h and 09h, August 10, and a high peak at 18h 31m during another similar disturbance between 17h and 19h, also on August 10, after which the storm gradually died down during another two and a half days of irregular oscillations.
Tucson Magnetic Observatory July to September, 1948
Authors: Nelson J. H.
Published: February 2008

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

July 28–31—A moderate storm began about 17h GMT, July 28. The variations were small and irregular for the first twenty‐four hours. From about 17h, July 29, until about 17h, July 30, magnetic conditions were quiet. Another 24‐hour period of moderately rough, irregular variations occurred, with the end of the storm coming about 18h, July 31.
Zô‐Sè Observatory July to September, 1948
Authors: Burgaud M.
Published: February 2008

(Latitude 31° 05′.8 N., longitude 121° 11′.2 or 8h 04m 45s E. of Gr.)

August 4—At 09h 48m GMT, there was small, abrupt beginning with slight activity during six hours.
Watheroo Magnetic Observatory July to September, 1948
Authors: Wood F. W.
Published: February 2008

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

There were no marked disturbances recorded during July.
Old magnetic declinations
Authors: van Bemmelen W.
Published: February 2008

On account of the renewed interest being paid to old magnetic observations, I should like to inform you that I am continuing my researches, the results of which I published in my paper, “De Isogonen in de XVIde en XVIIde Eeuw, Utrecht, 1893.”

The large number of old ship journals, in the government archives at The Hague, furnished me with a thousand new declinations, which enabled me to draw isogonic maps for the period 1540–1680, given in the above publication. From journals of later date, particularly for the years 1630–1720 and of the travels from Holland to the Cape of Good Hope, also found in the government archives, I have made extracts. There are, besides still older journals there, which were not used in the maps referred to. Among others, the independent observations made on four ships that sailed in company from India to Holland in the year 1677, are very valuable.
On the existence of vertical Earth‐air electric currents in the United Kingdom
Authors: Rücker A. W.
Published: February 2008

In a paper by Dr. Adolph Schmidt, read before Section A of the British Association at Oxford (Report Brit. Assoc., 1894, p. 570), the author stated that he had expanded the components of the Earth's magnetic force in series, and had deduced expressions, two of which give the magnetic potential on the surface of the Earth in so far as it depends on (1) internal, and (2) external forces. “The third series represents that part of the magnetic forces which can not be expressed in terms of a potential, but must be due to electric currents traversing the Earth's surface.” The author concludes that such currents amount on the average to about 0.1 ampere per square kilometer.

It appeared therefore desirable that this conclusion, drawn from the magnetic state of the Earth as a whole, should be tested by means of those portions which have been most fully studied.