bluuebunny/crossref_metadata_2025 huggingface dataset:
Sur la variation diurne des eléments magnétiques au Scoresby Sund (Est‐Groenland)
Authors: Rothé J. P.
Published: February 2008

En examinant rapidement les courbes enregistrées par les magnétographes La Cour à la station française de l'Année Polaire au Scoresby Sund (longitude, 21° 57′.7 W; latitude, 70° 29′.1 N), on est frappé par la régularité des variations diurnes des éléments magnétiques. Les résultats détaillés de nos observations sont publiés, sous la direction du Professeur Maurain dans les Annales de l'Institut de Physique du Globe de Paris1 et l'auteur résumera ici quelques observations inspirées par ce dépouillement.

Variation diurne de la déclinaison

Le régime diurne de la déclinaison est particulièrement net, avec un maximum vers l'est, vers 6 à 7 heures du matin (T. M. G.) et un maximum plus étalé vers l'ouest le soir vers 20 à 22 heures. Le graphique (Fig. l) représente l'allure des différentes courbes mensuelles, toutes très concordantes; il montre aussi que l'amplitude diurne moyenne suit une marche annuelle très accentuée passant de 16 minutes en janvier à 38 minutes en avril. La seule série d'observations comparables directement à nos mesures est constituée par des lectures horaires de déclinaison faites en 1891–1892 à l'île de Danemark, dans le Scoresby Sund, au cours de l'hivernage de l'expédition danoise Ryder.2 La variation diurne de la déclinaison y présentait une marche tout à fait analogue à celle que nous avons constatée; toutefois l'amplitude diurne moyenne était plus forte au printemps, atteignant 61 minutes en mars, parce que 1891–1892, à l'encontre de 1932–1933, correspondait à une période de maximum d'activité solaire.
Computed and observed rates of small‐ion production in the atmosphere
Authors: Wait G. R.
Published: February 2008

By the use of equations derived by Whipple from a theoretical basis Scrase has computed values of the coefficients of combinations between small ions and condensation‐nuclei, charged and uncharged, using data from Kew. The rate of small‐ion production also has been computed from the same data, also on the basis of Whipple's equations. In a similar manner, the combination‐coefficients and rate of small‐ion production have been computed by the author, using data taken at Washington, D.C. The results, both for combination‐coefficients and rate of small‐ion production, are in good agreement with those from Kew, but the production‐rate is not in good agreement with that determined by means of a thin‐wall ionization‐chamber. Computation of combination‐coefficient between small ions and large ions on the basis of simultaneous data on small ions, large ions, and rate of small‐ion production by means of a thin‐wall chamber, yield a value many times larger than that derived on the basis of Whipple's formula, and somewhat higher than that deduced by Harper from theory. The coefficient so obtained shows a definite diurnal variation somewhat similar in character to that for the rate of small‐ion production, or small‐ion content. The similarity to the diurnal variation in the reciprocal of large‐ion numbers is even more pronounced. Nolan's square‐root law, connecting rate of ionization, small‐ion numbers, and large‐ion numbers is not consistent, however, with the results here obtained. A new relationship between formation and destruction of small ions is found from the present results. Additional experiments are needed to test whether or not such a relationship has universal application.
Apia Observatory January to March, 1935
Authors: Wadsworth J.
Published: February 2008

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

January 27—A slight disturbance began at 14h 50m, G. M. T., with a sudden increase of 22 gammas in the horizontal intensity. A minimum value was shown at 5h 40m on January 28, the range of the disturbance being approximately 94 gammas. The vertical intensity increased initially by 4 gammas and then underwent slight irregular changes.
Numerical character‐figures of magnetic disturbance in relation to geomnagetic latitude
Authors: Stagg J. M.
Published: February 2008

§1. In recommending the publication of daily values of the quantity Cn= (HRH+ZRZ)×10−4 at a number of selected observatories the primary intention of the responsible sub‐committee of the International Union of Geodesy and Geophysics was to provide a numerical criterion for differentiating between days of greater or less magnetic disturbance at any one station. At best Cn has only a facial resemblance to one of the constituents in the expression for the total energy of the Earth's magnetic field. Without complex modifications to take account of the contributions to the quantity made by the regular quiet‐ and disturbed‐day variations Cn can hardly be regarded even as a rigorous comparative measure of the major features of disturbance at various observatories. To serve this purpose it would require to be shown that not only the same type of perturbation dominated disturbance at all observatories, so that the extreme daily range R and not, say, the mean hourly range, could be regarded as a universal index of disturbance, but that the dominant perturbations occurred at least within the same Greenwich day at all observatories.
Correlation between auroral and magnetic activities at Chesterfield, Canada, 1932–33
Authors: Davies F. T.
Published: February 2008

Fifty‐six clear nights of the winter of 1932–33 are chosen for this comparison of (a) inter‐diurnal and (b) diurnal auroral and magnetic activity. This eliminates the effect of cloudiness on auroral observations. The progressive effect, as the season changes, of increasing daylight on auroral observations, has been minimized by considering only the night hours from 18h to 6h. The intensity of aurora seen within a few minutes of the exact hour is expressed on a scale of 0 to 4 for increasing intensity.
Ueber die Nachlieferung von Radiumemanation aus dem Erdboden
Authors: Zeilinger von P. Robert
Published: February 2008

The amount of radon given off from the soil was measured by the method of P. Zupancic with certain improvements. During December 1933 to October 1934, 150 measurements were made at two points in a meadow near Hötting; observations were made alternately at these. The average value is 43.5 × 10−18 curie per cm2 per sec. Considering the fact that very few measurements were made in the autumn, it must be concluded that the annual average is nearly 50 × 10−18 curie per cm2 per sec. This amount of exhalation agrees well with the results of Smyth (Dublin) and Wright and Smith (Manila), who obtained 73 × 10−18 and 20.5 × 10−18 curie, respectively. It is interesting to note that P. Zupancic in the garden of the Institute in Innsbruck obtained an average exhalation of 23 × 10−18 curie per cm2 per sec (December‐July), that is, about half as much as the author on the meadow in Hötting where the soil was never mixed with fragments of brick, etc. It was found that the meteorological factors governing the exhalation of radon are not the same in different seasons of the year. In winter the influence of snow or ice on the ground prevails. The exhalation increases rapidly when the snow is melting. In spring rather large variations in the amount of exhalation were found corresponding to large differences of temperature, etc. A lawn‐covered area gives off less radon than an area of the same soil without lawn. The highest values of exhalation were found in July and August. The relationship of exhalation to different meteorological factors is discussed. Wind decreases the amount of exhalation measured. This may be due to the removal of radon within the collecting vessel by the small rapid changes of barometic pressure during high winds. The daily variation of exhalation was studied and found in good agreement with the curve of P. Zupancic. Simultaneous measurements of the radon‐content of open air showed a daily variation similar to that of the exhalation.
Earth‐current observations at Chesterfield, Canada
Authors: Currie B. W.
Published: February 2008

This is a summary of the report on the earth‐current observations made near Chesterfield Inlet (63° 20′ north, 90° 42′ west) during the International Polar Year to be published shortly by the Meteorological Service of Canada. The value of the earth‐current data in relation to the magnetic and auroral observations at Chesterfield is indicated.

Earth‐current observations had not been made in any part of northern Canada prior to 1932–33, and information was lacking concerning the nature and the magnitude of the earth‐current that might be expected inside the zone of maximum auroral frequency and close to the magnetic pole. The Department of Terrestrial Magnetism of the Carnegie Institution of Washington, had designed a recording circuit for use at the International Polar‐Year Station at College‐Fairbanks, Alaska, which provided a large range of sensitivities. That Department kindly loaned an earth‐current outfit embodying this circuit to the Meteorological Service of Canada for use at Chesterfield. A description of this circuit and a statement of its advantages can be found elsewhere1,2.
American URSI broadcasts of cosmic data April to June, 1935
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, solar constant, and aurorae are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g+s), where k for Mount Wilson is about 0.7.
Comment [on “Measures of terrestrial‐magnetic activity” by G. van Dijk]
Authors: Bartels J.
Published: February 2008

G. van Dijk presents evidence that the discrepancy between C and u (or u1), especially for the year 1930, may not be due to a break in the homogeneity of C, and stresses the usefulness of the international character‐figure C as a measure of magnetic activity not only for intervals of days and weeks (which is undisputed) but also for months and years. Some remarks on the latter point may be permitted, because it now seems quite feasible to ascribe most of the discrepancy found for 1930 not so much to inherent faults or failures of C and u1, but to the different conceptions of magnetic activity underlying both measures.

(1) April 1930 has the highest average monthly character‐figure, C = 1.04, of the whole series from 1906 to 1934. In the lists of “Principal magnetic storms” published in this Journal, however, all observatories, except Sitka, reported “no storm” for this month. On the other hand, May 1921, famous for two of the most intensive magnetic storms ever recorded, has only C = 0.83. The u1‐measure gives 52 for April 1930, and 132 for May 1921 (the second highest value for the series 1872 to 1934). This means that the mean monthly C fails to indicate the conspicuous absence of storms in April 1930 as compared with the outstanding storms in May 1921, while u1 represents these conditions satisfactorily.
Diurnal variation of intermediate and large ions of the atmosphere at Washington, D.C.
Authors: Wait G. R. , Torreson O. W.
Published: February 2008

Continuous records of the intermediate‐ion and the large‐ion contents of the atmosphere at Washington, D.C., were secured for identical samples of air, during the latter part of May and the first half of June 1933. The results reveal diurnal variations in the two sets of ions that are similar in character. The most prominent features of each is a pronounced maximum centering on about 21h, local time. For the 12‐hour interval, from 4h to 16h, both ion‐contents are low and undergo but minor variations. The variation in the number of intermediate ions from day to day is proportional to the variation in the number of large ions present, but the variation is correspondingly less during times of the higher than during times of the lower large‐ion content of the atmosphere. Intermediate ions are generally numerous during times of thunderstorms, not as a consequence of the Lenard effect, as surmised by Schachl, but probably because of the increased number of small ions present at such times. The increase in number of small ions is apparently due, according to previous results, to radioactive matter carried down by the rain after having been carried upwards from the Earth's surface through convection‐currents during the formation of the thunderstorm. Without further investigational work, the full significance of the similarity in character of the diurnal‐variation curves for intermediate and large ions is not fully apparent, but it appears that particles are coming into the atmosphere, assorted into two definite sizes, from a common source.
American URSI broadcasts of cosmic data July to September, 1935
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricty, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g+s), where k for Mount Wilson is about 0.7.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, July, August, and September, 1935
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

The magnetic storm of July 7 began with a sudden decrease of 4 gammas in the horizontal intensity followed immediately by an increase of 27 gammas. The most active spot‐group on July 7 was in latitude 34° south and longitude 45° east. A smaller group in latitude 22° north first appeared on July 7, 65° east of the central meridian, and developed its maximum area on July 9.

The most active group on September 10 was in latitude 18° south and longitude 72° west. This group first appeared on September 7 in longitude 27° west, and was moderately active from September 7 until it disappeared at the west limb on September 11.
Maxima of potential gradient at Apia
Authors: Sapsford H. B.
Published: February 2008

The average values of potential gradient of the atmosphere between successive hourly periods 0h–1h, 1h–2h, 23h–24h, on complete days free from negative potential during the period 1924–34 have been tabulated and the means of these average values for each year are given in Table 1. The departures of the hourly means from the daily mean have been plotted to give the curve (full line) in Figure 1, the departure for 0h–1h having been plotted as the ordinate at 1h and so on.

The harmonic analysis for this period of eleven years, using 24 ordinates and taking the mean average value for the period 23h–24h as the midnight value givesdV/dh = 115.3 + 15.8 sin (280° + 15t) + 33.6 sin (183° + 30t)+ 6.5 sin (30° + 45t) + 18.2 sin (295° + 60t) + 4.2 sin (146° + 75t)+ 9.1 sin (50° + 90t) where local midnight (zone time, that is, 165° west meridian time at Apia) is the epoch. Figure 1 also shows the curve (dotted line) for the above harmonic series omitting the first (constant) term. The fifth and sixth harmonics have been included because it was found that they decidedly improve the shape of the harmonic curve. The phase‐angle of the 24‐hour wave referred to midnight G. M. T. is 115° (280° zone time) and this agrees very well with the mean phase‐angle of 113° G. M. T. obtained at Mount Stromlo, Australia; but, as C. W. Allen1 points out, this represents a considerable retardation if compared with the 24‐hour wave of the world gradient, the phase‐angle of which is about 183° G. M. T. The maximum of the 24‐hour component at Apia is at 11h.3 zone time (22h.3 G. M. T.), whereas the actual maximum of potential gradient occurs between 8h and 9h (19h and 20h G. M. T.) in the morning and a secondary maximum occurs between 20h and 21h (7h and 8h G. M. T.) in the evening. From the analysis it is seen that the times of the maxima are determined mainly by the 12‐hour and 6‐hour terms, both of which have greater amplitudes than the first harmonic and hence the diurnal‐variation curve shows little resemblance to a single sine‐oscillation. In fact, under normal conditions the potential gradient in Samoa shows a strong 12‐hourly variation in the form of these two well defined maxima, the morning maximum usually being of higher potential and more protracted than the evening maximum.
A 42‐day comparison of four vertical‐intensity variometers of the knife‐edge type
Authors: Hartnell Geo
Published: February 2008

Four Z‐variometers of the knife‐edge type were operated simultaneously at the Cheltenham Magnetic Observatory for six weeks in 1935. Their relative performance was determined by comparing the ordinates for four periods of one hour for each day. The results indicate that variometers of this type, carefully designed and of superior workmanship, can be operated satisfactorily for observatory purposes, if they are kept free from mechanical jars and the supporting surfaces are kept clean.
Polarization of radio waves from the ionosphere near the geomagnetic equator
Authors: Wells H. W. , Berkner L. V.
Published: February 2008

While the polarization of radio waves returned from the ionosphere is generally elliptical because of magneto‐ionic double refraction, the theory predicts that, in the special case of propagation of a wave in the ionosphere with its wave‐normal perpendicular to the Earth's magnetic field at all points of the wave‐path, the two wave‐components returned should be plane‐polarized in mutually perpendicular planes. The Huancayo Magnetic Observatory (Peru) of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, some 2°10′ from the geomagnetic equator, is suitably located for the test of the polarization of the wave‐components returned under these special conditions. Polarization‐experiments have, accordingly, been conducted in this location with the following results: The two doubly refracted components are plane‐polarized in mutually perpendicular planes with the electric vector of the ordinary or o wave‐component polarized in the magnetic north‐south plane and of the extraordinary or x wave‐component in the magnetic east‐west plane. The reduction in refractive index of the medium for any given number of charges is found to be greater for the x wave‐component, validating previous assumptions of this nature based on the simple theory. The experimental results are in agreement with the general theory as applied to the special conditions. This confirms further this theory because of the lack of dependence of the results upon assumptions such as dissipation, etc., as are necessary when the wave is propagated obliquely to the Earth's field.
Provisional sunspot‐numbers for December, 1935 to February, 1936
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, October, November, and December, 1935
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

The only magnetic storm in the last quarter of the year 1935 began on October 20 at 10h 38m, G. M. T., and ended on October 22 at 6h. The range in the horizontal intensity (H) was 115 gammas. On October 24 at 6h 40m a sudden increase in H of 29 gammas was followed by a very moderate disturbance.

Sunspots have been numerous, large, and active but with apparently no effect on the Earth's magnetic field. Eighty‐seven spot‐groups were observed during the quarter, eight of which were large enough to be seen under favorable conditions without a telescope. Exceptionally bright hydrogen eruptions were observed on December 16, 17, 23, and 31.
Conversion of Berlin Earth‐current data to millivolts per kilometer
Authors: Gish O. H.
Published: February 2008

Doubtless others than the writer have at times desired to know the equivalent, say in millivolts per kilometer, of the arbitrary units used for expressing the valuable earth‐current data obtained at Berlin.

Recently an estimate of such an equivalent in millivolts per kilometer has been made on the basis of information given in an article entitled “Die Erdstrom‐Aufzeichnungen in den deutschen Telegraphen‐Leitungen” transmitted by Dr. von Stephan, Staats‐Secretär des Reichs‐Postamts1. Here (p. 558) one finds the statement (referring to Plate IX) : “In den Declinations‐Schwankungen bedeutet 1 mm nahezu 0.8 Bogenminuten, bei den Erdströmen dagegen die Hälfte der elektromotorischen Kraft eines Daniell‐ (Zink‐Kupfer) Elements (letztere von l Volt wohl nicht stark verschieden).” From this it appears that for the earth‐current graphs on Plate IX, one millimeter is at least roughly equivalent to 0.5 volt. The same scale is apparently also used for the earth‐current graph on Plate X. The range on that graph (in the case of the Berlin‐Dresden span) is 80 mm which is then equivalent to 40 volts or, since this line is 120 kilometers long, to 333 millivolts per kilometer, which is a reasonable value for a moderate storm.
Huancayo Magnetic Observatory October to December, 1935
Authors: Torreson O. W.
Published: February 2008

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

October 20–21—A mild disturbance, beginning inconspicuously at about 9h 10m with very small perturbations in all three elements, the perturbations gradually increasing in magnitude and period up to 13h and thereafter H, particularly, showing several large peaks and bays of 50‐ to 100‐gamma range, with periods of about one hour from crest to crest, until 20h. D and Z were considerably disturbed also during the period from 13h to 20h. On October 21, large bays and peaks occurred in H during the daylight hours (12h to 21h, G. M. T.), while D and Z were little disturbed. The end of the disturbance was not well defined. The ranges recorded were: Declination, 9′; horizontal intensity, 208 gammas; vertical intensity, 54 gammas.
Harvard University
Authors: Stetson Harlan T.
Published: February 2008

A communication just received at the Institute of Geographical Exploration from Dr. Carl Störmer (Norway) states that thus far no authenticated observations of the long delayed echoes such as were widely observed during the sunspot maximum of 1929 have yet been reported.

The recent rapid rise in sunspot‐numbers should indicate an early return of conditions favorable to reception of these echoes of long delay. Since the conditions most favorable for the phenomenon occur, as Dr. Störmer has pointed out (Nature, January 5, 1929), when the Sun is near the magnetic equator, we shall next be approaching these favorable conditions in February.
Apia Observatory January to March, 1936
Authors: Baird H. F.
Published: February 2008

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h27m.1 W. of Gr.)

Sudden rises in the value of horizontal intensity, followed by only slightly disturbed traces, occurred at 3h 32m, January 8; 9h 21m, February 14; and 10h 55m, February 16, The maximum rise, that on February 16, was of 23 gammas.
Provisional sunspot‐numbers for May to June, 1936
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
American URSI broadcasts of cosmic data, April to June, 1936
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, solar constant, and auroræ are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g + s), where k for Mount Wilson is about 0.7.
Huancayo Magnetic Observatory April to June, 1936
Authors: Torreson O. W.
Published: February 2008

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

April 17–23—A prolonged but mild disturbance, interesting chiefly because it occurred 27 days after a mild disturbance in March of similar character. This disturbance may be said to have begun with an inconspicuous sudden commencement at 18h 30m GMT, in all three elements. H increased 17 gammas in four minutes, while D and Z just perceptibly increased. Following this, H decreased steadily to a very low value by 3h on April 18. A similar decrease on several successive days, occurring between 0h and 5h, was the most conspicuous feature of the disturbance. On all days there were superposed on the H‐trace, numerous quite large bays and peaks which, while causing much irregularity, did not prevent the appearance of the usual diurnal character. Both D and Z showed numerous small perturbations throughout the disturbance, which did not affect the general diurnal trend. The end of the disturbance is very indefinite, the trace for April 23 being quite irregular while that for April 24 was comparatively smooth and quiet.
Watheroo Magnetic Observatory April to June, 1936
Authors: Green J. W.
Published: February 2008

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

May 29—There was a sudden commencement on May 29. Its time of beginning as recorded by the vertical‐intensity inductometer 8h 48m 00s GMT. H increased 12 gammas in three minutes; 7 gammas of the increase took place in the first half‐minute. H then decreased 77 gammas to minimum at 13h 32m and then increased 81 gammas to maximum at 21h 50m. Z increased 2 gammas abruptly, then 5 gammas in 12 minutes followed by disturbance in which Z had a range of 65 gammas with minimum at 13h 40m and maximum at 21h 50m.
Terrestrial‐magnetic activity in the year 1934
Authors: Bartels J.
Published: February 2008

The measures u and u1 of magnetic activity in the year 1934 were computed from the daily means of horizontal intensity at six stations. Only the observations for De Bilt were available in print; the Director of the United States Coast and Geodetic Survey kindly supplied the observational data for the four American stations Honolulu, San Juan, Tucson, and Cheltenham, and the Director of the Department of Terrestrial Magnetism, Carnegie Institution of Washington, supplied those for Watheroo Observatory (Western Australia), in advance of publication. Table 1 continues tables for 1872 to 1930 of u‐measure previously printed in the Journal1 (where the table for u is, by misprint, designated erroneously as u1) and of u1‐measure2, tables for 1931 and 19323 and for 19334. The relative merits of the two measures of terrestrial‐magnetic activity for which long series are available (namely the international magnetic character‐figures C and the u‐ or u1‐measure) have recently been discussed by G. van Dijk and the author in this Journal5.
Averages of critical frequencies and virtual heights of the ionosphere, observed by the National Bureau of Standards, Washington, D.C., 1934–1936
Authors: Gilliland T. R. , Kirby S. S. , Smith N. , Reymer S. E.
Published: February 2008

A program of measurements of critical frequencies and virtual heights of the ionosphere has been carried on by the National Bureau of Standards since January 1930. Results have been given from time to time in a number of papers published in the Bureau's Journal of Research, in Proceedings of the Institute of Radio Engineers, and elsewhere. One of the more recent papers (see 2 in list below) gave systematic data on critical frequencies of the various layers for the year May 1933 to April 1934, inclusive. Experimental evidence of the beginning of a long‐time increase of average critical frequencies was also given in that paper.
Dr. Nanabhai Ardesher Framji Moos, 1859–1936
Authors: Unakar Mukund V.
Published: February 2008

The death, on March 12, 1936, of Dr. N. A. F. Moos removed from the field of terrestrial magnetism one of its well‐known representatives during the last four decades. His scientific activities were intimately associated with the development of the magnetic work of the Bombay Observatory of which he was director from 1896 to 1919.

The selection of the present site of the Observatory at Colaba dates from 1823. It was inaugurated as an astronomical observatory and not until 1841 were magnetic and meteorological observations added to its activities. Only from 1846, however, was the Observatory properly equipped to take regular observations in magnetism and meteorology. In 1865 Mr. Charles Chambers was appointed its first full‐time superintendent and in a short time the Observatory was provided with autographic instruments for continuously recording the magnetic and meteorological elements and soon entered upon an era of real scientific activity both in regard to the collection of accurate data and to their discussion.
Provisional sunspot‐numbers for July to November, 1936
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
American URSI broadcasts of cosmic data July to September, 1936
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g + s), where k for Mount Wilson is about 0.7.
Cheltenham Magnetic Observatory July to September, 1936
Authors: Ludy Albert K.
Published: February 2008

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

July 1–3—A moderate disturbance began about 20h GMT, July 1, and ended just two days later. The beginning and ending were gradual. The disturbance was marked by rapid decrease in horizontal intensity of 27 gammas in 6 minutes at 4h 14m, July 2, and a decrease in vertical intensity of 39 gammas in 30 minutes at 7h42m, July 2. Ranges: Declination, 17′; horizontal intensity, 146 gammas; and vertical intensity, 113 gammas.
Earth‐current variations with periods longer than one day
Authors: Rooney W. J.
Published: February 2008

Examination of the earth‐current records from Tucson and Huancayo shows that the daily mean values recorded on characteristically disturbed and calm days differ consistently by a small amount. This suggests that a part of the current flowing during disturbances or magnetic storms is unidirectional for the day or longer and is the first definite indication of a component in earth‐currents with period greater than one day. The magnitude of the effect is small, not more than a few per cent of the range of diurnal variation at a given station. The direction of flow indicated is to the north and east at Tucson and to the south and east at Huancayo. These directions are consistent with those noted in the diurnal variations but they may be modified by local geological features. The reversal of direction of the northward component is also a feature of the diurnal variations when the stations considered are on opposite sides of the equator. The potential gradient due to earth‐current flow is so small at Watheroo, in proportion to the large and irregular contact‐potentials occurring there, that the Watheroo records are not conclusive on this point. In so far as they have any significance, the results are in agreement with those at Huancayo and consistent with the preferred direction of current‐flow found in the diurnal‐variation records. A wider distribution of stations and a more accurate quantitative measure of the effect is necessary before attempting to suggest a system of current‐circulation consistent with these results.
Huancayo Magnetic Observatory January to April, 1937
Authors: Davies Frank T.
Published: February 2008

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

January 27—A sudden commencement occurred at 03h 37m GMT, January 27. In four minutes H increased 28 gammas, Z increased 7 gammas, and D decreased 1′. The records were moderately disturbed from 07h to 14h.
Provisional sunspot‐numbers for June to August, 1937
Authors: Brunner W.
Published: February 2008

(Dependent alone on observation at Zürich Observatory and its station at Arosa)
The geophysical observatory of Chambon‐la‐Forêt
Authors: Harradon H. D.
Published: February 2008

The development of electric‐railway lines, particularly in the vicinity of large cities, has made necessary in recent years the transfer of several magnetic observatories to more isolated and magnetically undisturbed sites. Thus in the last decade it has been found necessary to move the principal magnetic observatory of Germany from Seddin to a new site at Niemegk and the Sverdlovsk (formerly Ekaterinburg) Observatory, where for nearly 100 years magnetic observations had been in progress, to Vyssokaja Dubrava, some 30 km from the old location.

We now learn from a booklet kindly furnished us by Professor Ch. Maurain, that the central magnetic observatory of France, previously located at Val‐Joyeux, about 25 km from Paris, owing to the encroachment of industrial electric currents, has been moved to a clearing in the Forest of Orléans, Commune de Chambon‐la‐Forêt (Département du Loiret), 87 km south of Paris. The geographical coordinates of the new observatory are latitude 48° 01′ 26″ north, longitude 2° 15′ 36′′ east of Greenwich, or 0° 04′ 38″ west of Paris; the elevation above sea‐level of the pier where the magnetic observations are made is about 133 meters. The greater part of the site lies in a clearing in the forest, the remainder being wooded. A determination of the magnetic susceptibility of several samples of the soil gave a mean value of 2×10−6, so that the soil may be regarded as practically non‐magnetic.
MacGregor Arctic Expedition, 1937–38
Authors: Johnston H. F.
Published: February 2008

This Expedition, under the command of C. J. MacGregor, Meteorologist of the United States Weather Bureau, left Port Newark, New Jersey, for the Far North on July 1, 1937. The Expedition hopes to arrive in Grinnell Land late in August and will establish its base at Fort Conger, Lady Franklin Bay, a station which was previously occupied by General A. W. Greely during the First International Polar Year in 1882–83. On August 17 the Expedition reported by radio being in latitude approximately 73° north near Thule, Greenland.

Commander MacGregor with eleven assistants sailed on the three‐masted schooner, General A. W. Greely. This schooner of 200 tons net registry was built for trading in the arctic regions. Her frame is extra strong and the massive knees to withstand ice‐pressure are all of natural wood. In addition her hull is encased by two extra sheaths of two‐inch planking of oak. Sails will be depended upon during the greater part of the voyage to the north, occasional assistance being given by two 40‐horse‐power Sterling marine engines. The twin propellers are protected from small pieces of ice by heavy oak‐casings.
American URSI broadcasts of cosmic data, April to June, 1937, with American Magnetic character‐figure CA, June to August, 1937
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g + s), where the mean value of k for Mount Wilson was 0.53 during 1936.
Sitka Magnetic Observatory April to June, 1937
Authors: Gebhardt Robert E.
Published: February 2008

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

April 24–25—A slight disturbance beginning abruptly at 12h 02m GMT, April 24, marked the beginning of several days of severe storms. This disturbance continued with increasing activity until it had reached its maximum intensity at 00h 10m, April 25. After about two hours the disturbance stopped quite sharply and in another five hours the three elements were normal. Ranges were: D, 69′; H, 545 gammas; Z, 298 gammas.
A connection between deep‐focus earthquakes and anomalies of terrestrial magnetism and gravity
Authors: Visser S. W.
Published: February 2008

Deep‐focus earthquakes—Earthquakes with extremely deep loci occur in well‐defined areas. The deepest foci, 600 km and more, are to be found in Japan, the Philippines, the Moluccas, and the Java Sea, in the Polynesian Archipelago, and in South America. Everywhere they are situated along an inclined surface, from the borders of the ocean sloping down below the continents. The slope of this surface is 30° to 40°.
Sitka Magnetic Observatory July to September, 1937
Authors: Gebhardt Robert E.
Published: February 2008

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

July 6–7—A slight disturbance occurred on July 6, characterized by a sharp movement in D and H (76 gammas decrease in H) at 0h 52m GMT. The elements remained calm until 11h at which time they began to decrease gradually until 14h 30m GMT, then started a slow but steady return to normal values. The trace was at its normal value about 03h GMT, July 7. The disturbance was marked by its uniform motion; sudden rapid oscillations were noticeably absent. Ranges: D, 31′; H, 211 gammas; Z, 331 gammas.
Ionospheric observations: Eclipse of June 8, 1937
Authors: Wells H. W. , Stanton H. E. , Seaton S. L.
Published: February 2008

Special ionospheric observations conducted at Huancayo (Peru) and Watheroo (Western Australia) for the eclipse of June 8, 1937 show:

(1) The day of the eclipse was normal, ionospherically.

(2) No eclipse‐effect for F‐region critical frequencies at Huancayo.

(3) The eclipse caused merging of the F1‐ and F2‐regions, followed by normal conditions at sunset, more than an hour earlier than usual.

The absence of any eclipse‐effect in the F‐region critical frequencies may be real or may be attributed to the fact that the eclipse did not occur at Huancayo until late afternoon. It is suggested that for such conditions ionizing radiation from the Sun would be greatly reduced by absorption in the Earth's atmosphere before the beginning of the eclipse due to the large zenith‐angle of the Sun.
Note on solar eruption of October 1, 1937, at Watheroo Magnetic Observatory
Authors: Green J. W. , Seaton S. L. , Hogan T. K. , Prior L. , Chamberlain N.
Published: February 2008

Between 11h 46m and 11h 49m, 120° east meridian time, October 1, 1937, echoes from the ionosphere faded put at Watheroo. Observations with the spectrohelioscope were immediately started and it was found that a solar eruption in the large sunspot‐group (approximate position, 12° south, 35° east) had occurred between the end of the preceding observation period at 11h 40m and the resumption of observations at 12h. The solar activity was judged to be of importance 3 at 12h, falling off gradually until normal conditions again prevailed at about 14h. Further ionospheric observations failed to show any echoes between 3.2 me/sec and 11.6 me/sec until 13h 50m when echoes were again seen on 4.8 me/sec, being weak until 14h 20m. The solar eruption had returned to an importance of less than 1 by 14h
American URSI broadcasts of cosmic data, October to December 1937, with American magnetic character‐figure CA, January to March 1937, and November 1937 to January 1938
Authors: Johnston H. F.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the foot‐note to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N = k (10g + s), where the mean value of k for Mount Wilson was 0.53 during 1936; during 1937 this value varied from 0.47 to 0.66, with an average value of 0.53.
Coil‐magnetometer and Earth‐inductor—A comparison of results obtained at the Abinger magnetic station of the Greenwich Royal Observatory
Authors: Greaves W. M. H. , Witchell W. M.
Published: February 2008

Dr. J. Egedal, Danish Meteorological Institution, Copenhagen, has recently made an examination of the results obtained at a number of magnetic observatories in the northwest of Europe, with special reference to the magnetic vertical intensity, Z, as derived from observations with earth‐inductors. In the course of his investigation the values obtained in 1934 at Abinger, both with the inductor and with the Dye coilmagnetometer for directly determining Z, were compared, and it seemed to Dr. Egedal that discordances could most easily be explained as due to an effect of temperature in the magnetometer. He communicated this opinion to the Royal Observatory, Greenwich, and it was felt there that the matter deserved a closer investigation than would have been possible to anyone not having full details of the observing conditions.

Accordingly the differences at Abinger in Z base‐line value as given by inductor and magnetometer have been analyzed, taking all days in the years 1934–37 on which determinations were made by both instruments.
The electric characterization of days at the Huancayo Magnetic Observatory for the 12 years 1925–1936
Authors: Torreson O. W.
Published: February 2008

Observations of the atmospheric potential‐gradient were begun by the Carnegie Institution of Washington at the Huancayo Magnetic Observatory, in Peru, in 1924. A photographically‐recording apparatus was installed at that time and has been in practically continuous operation up to the present. The data thus accumulated are now being tabulated for publication and will appear shortly, together with complete descriptions of the apparatus, its location, and particulars of the surrounding countryside.

At the inauguration of the observing‐program it was decided that the electric characterization of days as used by the British Meteorological Office at Kew Observatory should be adopted. This system has recently been described in detail by F. J. W. Whipple1 and need be mentioned only briefly here. There are three character‐figures, 0, 1, and 2. “0” denotes the absence of negative potential in any 24‐hour period beginning at midnight, “1” indicates the existence of negative potential at one or more times during the 24‐hour period but with a total duration of less than three hours, and “2” indicates the existence of negative potential for a total duration of three hours or more.
Aurora of January 22, 1938, at Bismarck, North Dakota
Authors: Langer Warren O.
Published: February 2008

An unusually extensive and brilliant auroral display was observed at Bismarck, North Dakota, on the morning of January 22, 1938. When first noticed by the writer at 3h 20m, it was mostly white (some red showing low in the north). It consisted of long narrow streamers reaching from close to the horizon to the zenith with rapid and steady pulsations which seemed to travel in waves from the horizon to the zenith. The aurora predominated in the northeast where the streamers were so close together as almost to form a sheet, although shorter streamers were visible in all directions, a number of which were broken into small segments.
Huancayo Magnetic Observatory, January to March 1938
Authors: Davies Frank T.
Published: February 2008

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

January 16–17—A marked sudden commencement occurred at 22h 37m GMT, January 16. In one minute, H increased 250 gammas, Z increased 24 gammas and then decreased 13 gammas, and D moved 2′.3 west and then 4′,4 east. Rapid oscillatory motions of the H‐spot continued until about 02h, January 17. Milder activity prevailed until 12h when severe and rapid changes began in horizontal intensity lasting until 18h. Between 14h and 15h there was a 355‐gamma bay in H. The minimal value in H was 29320 gammas at 16h 25m. There was another period from 21h 20m to 24h during which H was quite disturbed. The storm ended about 24h, January 17. Ranges: D, 12′.8; H, 505 gammas; Z, 62 gammas.
Final relative sunspot‐numbers for 1937 and monthly means of prominence‐areas for 1931–1937
Authors: Brunner W.
Published: February 2008

Table 1 contains the final sunspot‐numbers for 1937, for the whole disc of the Sun, based on observations made at the Zürich Observatory, supplemented by series furnished by other cooperating observatories for days (indicated by asterisks) on which no observations were possible at Zürich.

Table 2 gives the yearly means of the relative numbers, R, since the last minimum 1933 and the number of days without spots.