bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Höhe der Polarlichter und die Temperatur der oberen Atmosphäre
Authors: Angenheister G.
Published: February 2008

Die verschiedenen Erscheinungen, die zur Bestimmung der Temperatur der Atmosphäre über 35 km Höhe bisher benutzt wurden, werden besprochen. Sodann wird als neuer Weg hierzu die Verschiebung der Absorptionshöhe der Polarlichter beim Übergang vom Tag zur Nacht benutzt. Es wird für die helle und dunlde Atmosphäre eine mögliche Temperaturverteilung mit der Höhe angegeben. Diese führt für eine durchgemischte Atmosphäre zu einer Massen Verteilung, die den beobachteten Absorptionshöhen der Polarlichtstrahlen in der dunkeln und hellen Atmosphäre gerecht wird; sodass nämlich über den beim Wechsel vom Tag zur Nacht herabgesenkten Absorptionshöhen gleiche Massen erhalten bleiben. Danach müsste bei Tage die Atmosphäre in der Höhe von 100–200 km auf etwa 1000° abs. (darüber weniger) erhitzt werden und sich dadurch stark ausdehnen; bei Nacht kühlt sie sich in diesen Höhen wieder auf etwa 300° abs. ab und sinkt in sich zusammen.
Differences in diurnal variation of vertical magnetic intensity in Southern California
Authors: Soske Joshua L.
Published: February 2008

This paper sets forth the results of an experimental investigation of the diurnal variation in the intensity of the vertical component of the Earth's magnetic field in the northern half of Southern California. It also presents a discussion of the effect which the diurnal variation may have on the results of magnetic investigations of geologic features in this region. Attention was directed primarily to determining to what degree the diurnal variation is or is not constant over the various areas of the region regardless of the local weather prevailing at the different localities.

Southern California is divided into local topographic areas characterized by diverse atmospheric conditions. Areas open to oceanic breezes are frequently covered with fog and are consequently cool in summer; other districts closed to the sea by ridges may receive simultaneously extreme amounts of solar energy directly from the Sun, or may become heated by foehn or valley winds from adjacent regions. These variable local conditions of energy‐absorption and radiation may influence earth‐currents if they are considered as induced currents circulating in conductive paths in the Earth's crust. Any change in earth‐currents would influence magnetic intensities by the amount of change in magnetic flux produced by the disturbed earth‐currents.
On electrical rectification by the Earth's lower atmosphere
Authors: Gunn Ross
Published: February 2008

The relation of the current‐density to the impressed electric field‐intensity is worked out for the Earth's atmosphere, taking account of space‐charge. It is shown that the departures from Ohm's law are such that electricity is transferred outward from the Earth with greater ease than inward. Thus the large random alternating electric fields of the type observed during storms will result in a net upward transfer of electricity which may leak off over a large area and contribute to the normal or fair‐weather electric field. The fair‐weather field is downward and hence, with given field‐intensities, the electrical discharge of the Earth is more difficult than is the process of replenishment. The fundamental action of the atmosphere as an electrical rectifier, is emphasized.
Sitka Magnetic Observatory April to September, 1933
Authors: Ulrich Franklin P. , Burke R. G.
Published: February 2008

April 15‐April 21—This was a long drawn‐out storm of only moderate intensity. The curves of each element show for the most part irregular bays with no rapid pulsations except for only short intervals and then these were not very rapid and were of small range.

May 1‐May 2—This was a major magnetic storm. Because of the lower sensitivity of the H‐ and Z‐variometers on the recently installed magnetograph it was possible to secure much larger ranges in H and Z than usual. There was no definite time of beginning, the curves show small irregular fluctuations up to 12h on May 1 and then about two hours of large sharp bays. Shortly after 14h on the same day the motion of the spots was so fast and the amplitudes so large that the curves can be followed only with much difficulty. This lasted until about 18h 30m, May 1, and was followed by rapid oscillations lasting until 1h on May 2. The next five hours were relatively quiet and the rest of the storm showed small irregular bays.
AMERICAN URSI BROADCASTS OF COSMIC DATA
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, solar constant, and aurora 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 TerrestrialMagnetism and 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.
SITKA MAGNETIC OBSERVATORY JANUARY TO MARCH, 1934
Authors: Hershberger John
Published: February 2008

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

The only storm of importance occurred on March 5. The storm was preceded by a gentle but gradually increasing disturbance beginning about 13h, March 4, Greenwich mean time. On March 5, D and H increased very suddenly at 7h 45m and Z began to increase about 7h 52m. All reached their maximum values within a few minutes and their minimum values about an hour later. The values were about normal again by 13h but the record continued disturbed for several days. The ranges were: D, 118′; H, 660γ; Z, 466γ.
CHELTENHAM MAGNETIC OBSERVATORY JANUARY TO MARCH, 1934
Authors: Hartnell Geo.
Published: February 2008

(Latitude 38° 44′.0 N.; longitude, 76° 50′.5 or 5h 01m.4 W. of Gr.)

There were no magnetic storms recorded during the first quarter of 1934.
Vertical movements of the air in the upper atmosphere
Authors: Harang Leiv
Published: February 2008

In a number of papers Störmer1 has given the results of height‐determinations of aurorae lying in the sunlit atmosphere. The heights of these aurorae, consisting of rays and draperies, show a number of new features concerning the position of aurorae in space. In the sunlit atmosphere the upper limit of rays may extend to 800 to 1000 km whereas in the dark atmosphere the upper limit seldom reaches 300 km. Another remarkable feature is that the lower border of the rays seems to reach only the surface which separates the sunlit and dark part of the atmosphere and only occasionally penetrates this surface.
On the annual period of magnetic elements
Authors: Wasserfall K. F.
Published: February 2008

As compared with the diurnal variation of the magnetic elements, the annual period is, as we know, rather small. A characteristic of the annual period of the H‐component is that it shows a decided semiannual wave with its minima at the equinoctial seasons, corresponding to the time of the year when the magnetic activity is strongest. According to Ad. Schmidt the annual variation is to be interpreted as a vector of force oriented more or less along the magnetic axis of the Earth.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, January, February, and March, 1937
Authors: Nicholson Seth B. , Mulders Elizabeth E. S.
Published: February 2008

On January 27 from 19h 04m to 19h 45m, the magnetometer recorded a disturbance in the Earth's magnetic field, which occurred simultaneously with a complete fade‐out in short‐wave radio transmission on the Pacific Coast. H first decreased 41 gammas in 11 minutes, recovering 37 gammas in the next 30 minutes. Cloudy weather prevented solar observations at that time, although observations earlier in the day showed considerable activity on the Sun.

The February storm occurred when a very large active sunspot‐group was three days past the central meridian. Dr. Hubble reported seeing an aurora during this magnetic storm at 8h, GMT, February 3. He described the aurora as reddish in color with a few typical streamers.
Observations at secular‐variation stations in Mexico during 1936
Authors: Gallo Joaquín
Published: February 2008

During November and December 1936, R. O. Sandoval of the Magnetic Section of the National Astronomical Observatory of Mexico made observations of the absolute values of the magnetic elements at Mérida, Campeche, and Veracruz. The results of these observations are shown in Table 1. Mr. Sandoval's instrument was C.I.W.‐type magnetometer‐inductor No. 107 manufactured by the Precise Instrument Company, and the values shown in the Table are corrected to International Magnetic Standards.

The station at Mérida was at the airport 6.5 km southwest of the City, while at Campeche the station was also at the airport 1.5 km south of the Cathedral. At both of these stations observations could be made only at certain times of the day. At each station a small cement platform was constructed at ground‐level, the precise point being marked by a cross. An iron pole 800 meters to the north of each station marks the astronomical meridian. The station at Veracruz was 1.5 km north of the Plaza and without interference from buildings or ships.
Summary of the year's work, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Fleming J. A.
Published: February 2008

Terrestrial magnetism—During the year ended June 30, 1937, the program of the Department was devoted not only to experimental investigation, but also to the coordination and integration of isolated researches that the inferences of each may be more broadly interpreted. Such a program cannot be consummated within a limited period so that reports of successive years must bear similarities outlining the general progress and application of experimental fact as it is revealed. During the year the common goal and unity of the several branches of research have been admirably demonstrated.

Thus the association of a special type of magnetic disturbance and sharp fade‐outs of high‐frequency radio‐wave reflections with bright eruptions in the solar chromosphere, first pointed out by J. H. Dellinger, was conclusively proved by work of the Department in cooperation with Mount Wilson Observatory and other organizations. These effects are propagated from the Sun with the velocity of light. The active agent is believed to be ultra‐violet light originating in the solar eruption which produces sudden and intense electrification of the Earth's upper atmosphere. These new effects serve to discriminate between various theories of terrestrial‐magnetic changes and supply evidence on the electrical processes taking place in the ionosphere. The evidence yielded by the automatic recorders at the Huancayo and Watheroo observatories concerning the nature of the radio “fade‐out” effect indicates that this phenomenon is predominantly due to an intense ionization between heights of about 60 and 100 km. The high ionization produced below the lower E‐region of the ionosphere by bright chromospheric eruptions apparently causes radio‐echo disappearance through absorption in this region of high collisional frequency. A definite magnetic effect is observed during the fade‐out. Analysis of this effect shows it to be an augmentation of the magnetic diurnal variation as contrasted with other types of magnetic disturbance. The association of a magnetic effect of the diurnal‐variation type with a definite region of the ionosphere through experimental observations forms a contribution of first importance to the science of terrestrial magnetism. The simultaneity of the fade‐out, magnetic, and earth‐current effects with solar outbursts in the region of sunspot‐areas was confirmed by direct observation at the Huancayo Magnetic Observatory.
Lunar diurnal variation in Earth‐currents at Huancayo and Tucson
Authors: Rooney W. J.
Published: February 2008

The lunar diurnal variation in earth‐current flow at Huancayo and Tucson has been determined from the records for the year 1932, near the sunspot‐minimum. Using the method employed by Chapman for the magnetic elements, a definite lunar diurnal variation of markedly double period is found in both components of the potential‐gradient at both stations. Harmonic analyses of the mean curves show that at Huancayo the amplitude of the second harmonic is about one‐sixth that of the solar diurnal variation for the same year, while the amplitudes of the first, third, and fourth harmonics are negligibly small. At Tucson the amplitude of the second harmonic is about one‐fifth that of the solar diurnal variation for the northward component which is the principal component at that station.

The manner in which the lunar diurnal variation changes with the phase of the Moon was also examined. For both components at Huancayo, curves constructed for the four main phases of the Moon show a marked increase in activity during daylight hours and a corresponding diminution during the night so that the individual curves are no longer semi‐diurnal. For Tucson the curves for the individual phases of the Moon, as determined from this single year's record are too irregular to show the changes definitely, but do indicate that they are less pronounced at this higher‐latitude station. As a check on this point the lunar diurnal variation at Tucson was redetermined by the method applied by Egedal to the data from Ebro. In this method the lunar diurnal variation is obtained from the records for the individual hours of the solar day. Using the hours from 12 to 24 the lunar diurnal variation found is in good agreement with that obtained by the usual method. Comparing the lunar diurnal variation obtained separately by this method during daylight, 12h to 18h, with that obtained during the night, 18h to 24h, there is found only a slight decrease in amplitude from day to night and very little change in phase. These results are in agreement with those obtained by the first method and also with the revised conclusions reached by Egedal from his studies of the Ebro records.
Watheroo Magnetic Observatory, January to March 1938
Authors: Green J. W.
Published: February 2008

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

January 16–17—This storm, beginning at 22h 30m GMT, January 16, reached its greatest intensity on January 17. Ranges: D, 38′; H, 246 gammas; Z, 254 gammas.
Condensation‐nuclei in the atmosphere at the Huancayo Magnetic Observatory, Peru, and their relation to atmospheric‐electric and meteorological observations
Authors: Torreson O. W.
Published: February 2008

Measurements of condensation‐nuclei near the ground were made daily with an Aitken pocket counter from June 1, 1934, to December 31, 1936. Simultaneous observations were made of potential‐gradient and conductivity of the atmosphere, and daily records were kept of rainfall. The data are grouped in monthly means for discussion. In the dry season, when there are only a few days on which rain falls each month, the nuclei are numerous, averaging more than 20,000 per cc, while in the wet season, when there is some rain nearly every day, the average is less than 10,000 per cc. The conductivity of the atmosphere responds to the change in nuclei‐concentration, being conspicuously higher when nuclei are few than when they are numerous. Potential‐gradient shows less response than conductivity to changes in nuclei‐concentration, but in general shows a variation similar to that for nuclei. Computed values of air‐earth current show definite response to changes in nuclei‐content, being smallest when the nuclei are most numerous. This suggests that nuclei exist in sufficient quantities and to such heights above the Observatory as to significantly affect the total resistance of the atmosphere there. Detailed study of the daily observations in the dry month of June in all three years give added support to these conclusions. The data for the three June months are subjected to analysis on the basis of formulas proposed by F.J.W. Whipple and H.L. Wright for determining the size of the nucleus and the combining‐coefficients, η1 and η0, for charged and uncharged nuclei with small ions. The rate of production of small ions is assumed to be ten pairs per cc per second. The radius of the nucleus varies only between 1×10−6 and 3×10−6 cm when nuclei are more numerous than 10,000 per cc. For few nuclei, 1000 or 2000 per cc, the radius becomes 12×10−6 cm. These values of the radius are uncertain to 20 or 30 per cent, depending on the validity of various assumptions in the calculations. Values of η1 and η0 decrease rapidly with increase in nuclei up to 10,000 nuclei per cc. Thereafter η0 is comparatively small (less than 1×10−6) and η1 may be regarded as constant at about 2.5×10−6. Less than one‐fifth of the nuclei are charged, of one sign, when the concentration is greater than 10,000 per cc.
Magnetic Observatory, Capetown January to March, 1939
Authors: Ogg A.
Published: February 2008

January 4—There was a small disturbance at 23h 05m GMT, January 4. The changes were: H, −12 gammas in six minutes; Z, −14 gammas in ten minutes.

January 5—There was a small disturbance at 04h 08m GMT, January 5. The changes were: D, −4″.0 in six minutes; H, −21 gammas in six minutes; Z −32 gammas in thirty minutes.
Wide‐range magnetograph at Washington, D.C.
Authors: Fleming J. A.
Published: February 2008

An experimental installation has been set up in the Standardizing Magnetic Observatory of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington intended primarily for the experimental development of geomagnetic equipment and appliances. Further, it will serve for the general training of observers assigned to duty at observatories. As in the past, standardization of instruments, tests of sensitive apparatus, and final instruction of observers will be done at the Cheltenham Magnetic Observatory of the United States Coast and Geodetic Survey with the close cooperation of that Bureau and the Department of Terrestrial Magnetism.

This includes a wide‐range magnetograph, which will also provide complete records of such violent magnetic storms as those of March 24–25 and 29–30, 1940. La Cour variometers for declination, D, and horizontal intensity, H, and the CIW induction‐variometer for vertical intensity, Z, with scale‐values adjusted to about 30 gammas per mm, record on the drum of a la Cour magnetograph, with a time‐scale of one hour=15 mm, and automatic time‐marks every ten minutes. The photographic sheets are 300 mm wide, and the quiet traces are kept near the center of the sheet so that deflections up to 3500 gammas may be recorded.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, January to March, 1940
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

The magnetic disturbances beginning on January 3, 10, 30, and February 24 were probably all associated with the very large group of sunspots whose successive central meridian passages occurred on January 5.5 (Mount Wilson No. 6725), February 1.8 (No. 6741), and February 28.5 (No. 6756).

The same group crossed the central meridian for the fourth time on March 27.0 (No. 6784). On the previous appearances it had been a typical bipolar group, but now all that remained was the principal preceding member—a round stable unipolar spot.
The magnetic storm of March 24, 1940
Authors: McNish A. G.
Published: February 2008

Disturbance of electric power‐systems during the great magnetic storm of March 24, 1940, has created a new interest in the study of geomagnetic phenomena. Operation of telegraph‐instruments by electric currents induced by geomagnetic changes was observed shortly after the art of wired telegraphy had been introduced, and the effects of magnetic disturbances on the ionosphere, and consequently on radio transmission, were recognized with the advent of short‐wave transmission. But there have never been any previous reports of interference with power‐transmission. Clearly, only the most violent of magnetic storms are capable of affecting power‐systems for none of the other great storms of the present sunspot maximum gave rise to noticeable effects.
Sitka Magnetic Observatory April to June, 1940
Authors: Gebhardt Robert E.
Published: February 2008

April 2–3—A small magnetic storm began gradually at about 17h GMT, April 2, and slowly increased to maximum values at 04h, April 3. During the major portion of the storm the traces moved with large regular periodic motion. After 10h, April 3, the storm gradually decreased. Ranges: D, 166′; H, 769 gammas; Z, 610 gammas.
Huancayo Magnetic Observatory April to June, 1940
Authors: Wells H. W.
Published: February 2008

April 1–3—Moderate disturbances were recorded during this period.

April 25–26—There was a sudden commencement at 02h 06m GMT, April 25, which was followed by moderately disturbed conditions through 06h, April 26.
Alibag Magnetic Observatory January to March, 1940
Authors: Rangaswami M. R.
Published: February 2008

January 3–4—A moderate storm of short duration began with a sudden commencement at 14h 41m GMT, January 3, with a rise of 22 gammas in H. Attaining its maximum at 14h 50m, January 3, H fell rapidly with occasional jumps, reaching its minimum at 17h 01m, January 3. Thereafter, H rose and attained its pre‐storm value at about 22h.5, January 3. Minor fluctuations continued and the storm ended at 04h.5, January 4.
Ionospheric changes associated with the magnetic storm of March 24, 1940
Authors: Berkner L. V. , Seaton S. L.
Published: February 2008

Observations of the ionosphere at the Huancayo and Watheroo magnetic observatories during the great magnetic disturbance of March 24, 1940, are shown and discussed. At Huancayo, the ionospheric disturbance began about 40 minutes before the first really large magnetic change, though coinciding with increasing magnetic activity. During the first great magnetic changes, the F2‐layer was swept upward and disappeared in about 30 minutes. At the same time, ion‐density of the E‐layer rose about 40 per cent.

Growth of a “new” F2‐layer began after disappearance of the old, proceeding in an apparently normal manner for the next hour. Because the original ion‐density had been reduced to a low value, the F2‐region is regarded as a nearly un‐ionized atmosphere, suddenly exposed to solar radiation. Effective recombination‐coefficient and rate of ion‐production at level of maximum density of F2‐region are estimated from this growth. This yields approximate values of α = 1.8 × 10−10 and q0 = 230. These values must be somewhat larger, and must increase downward, if height‐change during growth of the layer is to be explained without electron‐transport during the interval.

Steady growth of the new F2‐layer was followed by a succession of abnormal increases and decreases of ion‐density of diminishing amplitude at an almost regular period of three hours for three and one‐half or four periods. Abnormal rate of decrease and subsequent increase of abnormal electron‐production at level of maximum is computed for the first period. This varies between −1000 and +1700 electrons per cc per second.

At Watheroo Magnetic Observatory ionospheric changes followed the general pattern usually experienced during magnetic disturbances in temperate zones. Evidence indicates large spatial tilts of iso‐ionic surfaces near Watheroo about 40 minutes after beginning of great magnetic changes. These spatial tilts were followed by rapid rise of height and increase of scattering.

Abnormal decrease of ion‐density of the F2‐layer at both observatories began simultaneously, within observational limits, less than 15 minutes after the first great geomagnetic change. The great rise in height at Watheroo lagged behind that at Huancayo by nearly an hour. A chronology of radio fade‐outs and bright chromospheric eruptions before and during the storm is given.
American URSI broadcasts of cosmic data, with American magnetic character‐figure CA, July to September, 1940
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 three columns for each month in Table 1 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.
Notes on Isomagnetic Charts: III—The Isogonic and X‐, Y‐Charts for the Centered Dipole Field
Authors: Chapman S.
Published: February 2008

Summary—Various forms of the equations of the isogonic lines are derived, for the field of the centered magnetic dipole. The isogonic chart for this field is shown to have two singular points in addition to the four uniform ray‐poles (one at each magnetic or geographic pole); these singular points, which are situated at the intersections of the magnetic and geographic equators are rectangular nodes. The equation and form of the nodal curves are discussed. The area over which the magnetic declination exceeds the obliquity of the magnetic axis is also considered; it is shown to cover more than a third of the whole area of the sphere, however small the obliquity may be.

The Y‐ and X‐isomagnetic charts are also briefly considered; the former has only two singular points, namely non‐uniform ray‐poles at the geographic poles; these are also (non‐uniform) ray‐poles of the X‐chart, which in addition has two nodes at the same points as those of the D‐chart; but in the case of X these nodes are not rectangular.
The Lunar Diurnal Variation of the Horizontal and Vertical Magnetic Forces at the Polar‐Year Station Mogadiscio
Authors: Egedal J. , Bossolasco M.
Published: February 2008

An article on the lunar diurnal variation of the magnetic declination at Mogadiscio has already been published in this Journal.1

The main results of a derivation of the lunar diurnal variation of the horizontal and vertical forces at the same place are given below. A more detailed account in Italian has been published in “Geofisica pura e applicata.”
Sitka Magnetic Observatory, October to December, 1940
Authors: Gebhardt Robert E.
Published: February 2008

October 7–8—A moderate magnetic disturbance began gradually at about 05 h GMT, October 7. The disturbance was marked by its long period motion of relatively small amplitude. The disturbance ended about 17 h GMT, October 8. Ranges: D, 114′; H, 400 gammas; Z, 114 gammas.
A Persistent Solar‐Rotation Period of 27.26 Days
Authors: Clayton H. Helm
Published: February 2008

Summary—This paper attempts to show: (1) The persistence of sunspot‐outbreaks in the same longitudes of the Sun for long intervals of time and the mean length of the solar‐rotation period derived therefrom; (2) the solar‐rotation period, as shown by the spots varies in length with the mean latitude of the spots. The period is longest after sunspot‐minirnum when the spots are in high latitudes and shortest a year or two before the next minimum when the spots are in low latitudes, in agreement with findings of Bartels, using other methods. The mean length is 27.26 days, slightly shorter than the value 27.28 days found by Carrington, and the period seems to return in the same phase in the same part of the 11‐year period in the case of data here used; (3) there is also evidence suggesting solar periods differing from 27 days.
Apia Magnetic Observatory, October to December, 1940
Authors: Sapsford H. Bruce
Published: February 2008

November 12–13—This disturbance began at 07 h GMT, November 12, and was in the form of a steady decrease in H, which set in after a poorly defined maximum at 21 h. The minimum, 184 gammas below the maximum, was recorded at 05 h 34 m, November 13. The elements then gradally returned to normal values.
The Ionosphere at Huancayo, Peru, July to September, 1940
Authors: Wells H. W. , Coile R. C.
Published: February 2008

This report is a continuation of those already published in this Journal1 and gives monthly mean hourly values of the heights and penetration‐frequencies of the ionosphere as obtained by means of automatic multifrequency ionospheric recording apparatus located near Huancayo, Peru, South America, in latitude 12° 02′.7 south, longitude 75° 20′.4 west of Greenwich, which operates over the frequency‐range 0.516 to 16.0 Mc/sec. A complete discussion of these data will be made in an annual summary.

Table 1 gives the monthly mean hourly values of the height of maximum electron‐density (hmax), uncorrected for retardation in lower regions2, and the minimum virtual height (hmin) for both the F1‐ and F2‐regions, the penetration‐frequencies for the E‐, F1‐, and F2‐regions, and the lowest frequency at which echoes were observed when that frequency was higher than 0.516 Mc/sec.
Magnetic Character, January to June, 1940
Authors: van Dijk G.
Published: February 2008

I have pleasure in giving below the lists of the selected five calm and five disturbed days and the days, recommended for reproduction for the period January to June 1940 and should feel much obliged to you if these data could be inserted in one of the next numbers of the Journal.

The following days are recommended for reproduction:Very greatly disturbed, March 24, March, 29, 1940; greatly disturbed, January 3, April 2, April 25, June 25, 1940.
Huancayo Magnetic Observatory, December, 1940, to March, 1941
Authors: Ledig Paul G.
Published: February 2008

December 20–25—A moderate disturbance in H accompanied also by definite disturbances in D and Z began gradually about 13h GMT, December 20, and was marked by a series of sharp peaks and bays lasting until about 20h. The disturbance was followed by subnormal values and mild disturbances in H until December 25.

December 31—A sharp disturbance in H of short duration was recorded on December 31. It began at 13h 25m GMT, with a rapid rise followed by a rapid fall to a narrow bay, then about an hour later at 14h 30m a rise of 170 gammas occurred in ten minutes to reach a high peak followed by a fall of 300 gammas to a sharp bay in twenty minutes. The next three hours was a period of moderate disturbance, followed by several hours of subnormal values in H and with a return to practically normal conditions at 22h. Both D and Z were somewhat disturbed from the beginning of the storm until after 17h.
SOME EARLY CONTRIBUTIONS TO THE HISTORY OF GEOMAGNETISM—IV
Authors: Harradon H. D.
Published: February 2008

Georg Hartmann—On March 4, 1544, Georg Hartmann, Vicar of the St. Sebaldus at Nuremberg, addressed a letter to Duke Albrecht of Prussia in which he announced his discovery of the magnetic inclination and the first determination of the magnetic declination on land. We reproduce here (page 129) Hellmann's facsimile of the first page of the original of the letter which is in the Kgl. Staatsarchiv in Königsburg. This letter has been printed several times; first by J. Voigt in Raumers Historisches Taschenbuch, II (1831), then by H. W. Dove in Repertorium der Physik, II (1838), and later again by J. Voigt, together with other letters by Georg Hartmann in “Briefwechsel der berühmtesten Gelehrten des Zeitalters der Reformation mit Herzog Albrecht von Preussen” (Königsburg, 1841).
SOME EARLY CONTRIBUTIONS TO THE HISTORY OF GEOMAGNETISM—VI
Authors: Harradon H. D.
Published: February 2008

Gerardus Mercator (Latinized for Gerhard Kremer) was a Flemish mathematician and geographer, born at Rupelmonde in Flanders, March 5, 1512. He studied at Bar‐le‐Duc and Louvain. In the latter place he established in 1554 his Geographic Institute from which was issued in 1537 the first‐known of the important list of maps and globes which brought him fame. In 1552 he moved to Duisberg where in 1568 he published his first map (Nova et aucta orbis terrae descriptio ad usum navigantium accommodata) with meridians and parallels at right angles—the so‐called “Mercator's projection.”
American Magnetic Character‐Figure, CA, Three‐Hour‐Range Indices, K, and Mean K‐Indices, KA, for April to June, 1944
Authors: Johnston H. F.
Published: February 2008

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

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

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

April 2–6—Beginning about 06h 26m GMT, April 2, a disturbance was severe until about 13h with K‐indices of 9, 9, 8 being recorded. With the exception of the period between 07h and 11h, April 6, when a K‐index of 8 was reached, activity was moderate.
On Contributions to the Early History of Geomagnetism
Authors: Espenschied L.
Published: February 2008

Here are a couple of related observations that may be of interest to the JOURNAL in case they have thus far escaped attention:

It appears that one of the earliest of the electrical experimenters, one Otto von Guericke, of the mid 1600's, was led to make his experiments in generating electricity by means of a rotating sulphur globe by having entertained an electrical theory in lieu of the then magnetic conception of the gravity of the Earth. This is brought out in what to me was a charming article upon the subject of von Guericke, by Thomas Coulson, which appeared in the September and October issues of 1943 of the Journal of the Franklin Institute. I myself am an appreciative owner of von Guericke's book. ... I have been hoping that some scholar might eventually find enough interest in the Experimenta Nova to render it into English. Not only would it be interesting to know what von Guericke's ideas really were in this respect, but it is conceivable that since they were not subject to the limiting influence of our subsequent findings and mode of thought, there might be in them some refreshing novelty and suggestiveness.
Geophysical Work in the Union of Soviet Socialist Republics
Authors: Pushkov N.
Published: February 2008

For a better understanding of geophysical operations in the U.S.S.R. I should like to give some details concerning our work during the last few years.

The Institute of Terrestrial Magnetism was established in 1940. At first we had only two sections, namely, (1) a group for magnetic survey on land in Leningrad and (2) a magnetic observatory at Pavlovsk (Slutsk). A short time afterward, several new groups were organized as follows: for magnetic survey at sea; magnetic cartography; theoretical investigations; superintendence of magnetic observatories; and some others. The Slutsk Ionospheric Station and the Magnetic Observatory were incorporated into the Institute.
On the exhalation of radon from the Earth
Authors: Cullen Thomas L.
Published: February 2008

Measurements were made, according to the method of Zupancic, of the rate at which the Earth exhales radon. A metal vessel was placed over a section of lawn near the Physics Building, Fordham University, and after a period of accumulation a sample of the gas was withdrawn from the vessel into an ionization‐chamber and measured for radon‐content. The average exhalation from August, 1944, to February, 1945, was 8.92 × 10−18 curie per cm2 per sec. The effect of temperature was studied and it was found that a maximum exhalation was reached in hot weather and a minimum in cold weather. Snow, it was observed, choked off exhalation and produced very low values in January and February. The effect of rain is complex, heavy rains producing at first great exhalation, then lower values. A study of hourly variations was attempted and a maximum was found for the morning period of 04h to 12h.
Apia Observatory October to December, 1945
Authors: Beagley J. W.
Published: February 2008

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

October 11–13—A period of minor disturbance commenced with a small positive bay at 22h GMT, October 11, and lasted until 11h, October 13. The principal features were bays in H during the fourth three‐hour period of October 12 and the third three‐hour period of October 13, giving K‐indices of 5 and 4, respectively. There were only slight fluctuations on the Z‐trace, and D\ was undisturbed.
Electrical effects associated with a change of state of water
Authors: Dinger J. E. , Gunn Ross
Published: February 2008

A method for measuring the change in contact‐potential of a water‐air interface as the water freezes or melts is described. These measurements indicate that a change of the order of ten volts rapidly occurs at the time of freezing of the surface of the water. After freezing this contact‐potential diminishes, the rate depending upon the temperature of the ice, until the potential is approximately that which existed before freezing. The melting of the ice produces no appreciable change in the contact‐potential. A method for approximately measuring the charge acquired by air passing over a given volume of freezing or melting water is described. A method of measuring the charge acquired by a given volume of water upon melting is described and the results are consistent with other measurements which determine the charge acquired by the air in contact with the melting water. Distilled water that has been frozen in an atmosphere of air, upon melting acquires a positive charge of approximately 1.25 esu for each cc of melted water, and simultaneously the surrounding air acquires a negative charge of 1.25 esu for each cc of the melted water. The presence of impurities reduces and with sufficient concentration neutralizes this charging‐effect accompanying the melting process. The presence of dissolved gases is essential for the observed charging‐effect to occur. This fact indicates that the charging‐effect is related to earlier experiments on the cataphoresis of gas bubbles as described in the literature. No important charge‐production accompanies the freezing of even pure water in the absence of dissolved gases.
Simultaneous observations of field‐intensity measurements of WWV at Needham, Massachusetts, and at Intervale, New Hampshire, during the summer of 1947
Authors: Stetson H. T. , Pickard G. W.
Published: February 2008

A study of continuous field recordings of WWV at Needham, Massachusetts, 373 miles from the transmitter at Beltsville, Maryland, has revealed that the diurnal pattern of reception undergoes a progressive metamorphosis, not only with the seasons, but with the change in sunspot‐numbers. This suggests the possibility of predicting fields over a given path based on actual records of performance, provided the records obtained at Needham are representative of a considerable area throughout which such variations may take place.

An experimental field station for recording field intensities of WWV, operated during the summer of 1947 at Intervale, New Hampshire, at a distance of 463 miles from Beltsville, has made possible direct comparison with fields obtained at the Cosmic Terrestrial Research Laboratory at Needham over the same interval. Results show the same general form of diurnal variation at the two stations for both the 5‐Mc and the 10‐Mc frequencies. The logarithm of the ratio of the 5‐Mc fields Needham/Intervale ranges from 1.3 at night to 1.7 during the noon hour.

Subsequently, the mobile recorder was set up at New Haven, Connecticut, at a distance of 270 miles from Beltsville, and simultaneous recordings were made during the autumn of 1947 with similar results. Sudden ionospheric disturbances and major fadeouts have been observed to occur simultaneously at Intervale and Needham, and at New Haven and Needham. The results of these investigations indicate that the changing patterns observed at Needham must essentially apply to a considerable area approximating at least a hundred‐mile radius from the Laboratory at Needham.
Apia Observatory October to December, 1947
Authors: Beagley J. W.
Published: February 2008

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

September 30‐October 3—A sudden commencement at 20h 02m GMT, September 30, introduced a period of moderate activity. Small, irregular movement disturbed the trace during October 1. H diminished fairly rapidly between 00h and 05h, October 2, after which stronger bay‐like movement developed. Conditions returned to normal at 14h, October 3. K‐index 5 was recorded during the fourth and eighth three‐hour periods, October 2, and the third three‐hour period, October 3.
Watheroo Magnetic Observatory October to December, 1947
Authors: Wood F. W.
Published: February 2008

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

November 9–10—A moderate disturbance commenced suddenly at 08h 57m GMT, November 9. H increased rapidly and then more slowly by a total of 39 γ in six minutes. D showed an easterly movement of 16′ before moving again towards the west, while Z decreased by 16 γ in the same time. H showed a downward trend from 12h to 13h, while at the same time Z increased, and all elements showed a few large and irregular movements which continued for the next thirteen hours. H remained depressed until 11h 50m, November 10, by which time movements in all elements had become only very slight. Ranges: D, 20′; H, 166 γ; Z, 168 γ.
The Earth, a great magnet
Authors: Fleming J. A.
Published: February 2008

When the invitation came to me to address this evening a lecture to a Liverpool audience in accordance with a usual custom during meetings of the British Association, the natural desire arose to select some subject which should have a more or less close relation to the industries and commerce of your great city. With a choice somewhat limited by the nature of my own studies, it seemed to me, however, that we might find an appropriate topic in discussing, for a brief hour, the fact of the earth's magnetic properties, and the history of the discoveries by which that supremely important knowledge has been gained.

To do this with advantage, we shall approach the subject through the avenue of some experimental demonstrations intended to place you in possession of the elementary principles of magnetic science.
Results of magnetic observations on the Rigi, made in 1895 and '96
Authors: Van Rijckevorsel  , Van Bemmelen
Published: February 2008

In the spring of 1896 we completed, as we thought at the moment, the magnetic observations on and near the Rigi, commenced in 1895 with the intention of determining the influence which the altitude above sea level might have on the magnetic elements. After a careful discussion of the results, we came to the conclusion that our observations show that, as far as the Rigi is concerned, the horizontal component decreases slightly with the altitude, while the vertical one increases in a somewhat larger degree. This increase, however, seems not to be larger than about 0.000 20 (C. G. S.) for 1 kilometer. These quantities are very small, if one bears in mind what the unavoidable errors of observation are.
Formal models in the design of water resource systems
Authors: Dorfman Robert
Published: February 2008

New methods for designing water resource systems are being evolved as part of a general social tendency toward expressing social problems in the formal modes that have hitherto been restricted to scientific and engineering problems. Two general types of model have been fruitful in the field of water resource development: the simulation model and the analytic model. In simulation models temporal sequences of events are reproduced on electronic computers on a time scale in which minutes represent decades, leading to convenient estimates of the consequences of design decisions even in complicated circumstances. In analytic models consequences are expressed as explicit mathematical functions of design variables. Simulations are awkward when a wide range of design decisions has to be evaluated ; analytic models cannot be applied to practical problems without drastically simplifying them. But the two methods can be used in tandem, with analytic models delimiting the range within which simulation is required.
Water problems
Authors: Thomas H. E.
Published: February 2008

Viewed from the perspective of the Moon, we could readily see that water is the most abundant mineral on Earth. About 71% of the spheroid's surface is formed by oceans, another 3½% by polar icecaps, and the remaining 25½%, constituting the land masses, is at various times and places obscured by water in the vapor phase, covered by water in the solid phase, and is draining or storing water in the liquid phase.

Where there is life there must be water. Every organism on Earth, plant or animal, is dependent on it. The biologist finds plants, animals, entire ecosystems, adapted to practically every environment on Earth, though ranging widely in abundance and variety: least numerous in the intense pressures of great ocean depths and the intense cold of high mountains and polar icecaps, most numerous where the land surface or ocean bottom is within 600 feet of sea level. Characteristically the terrestrial organisms are adapted to the fresh water that comes from precipitation and occurs in the soil, streams, lakes, and rock materials of the continents and islands. Both plants and animals are adapted to the great variety of environments thus available, ranging from deserts and tundras to rain forests and swamps and lakes. The water quality may range from ‘pure as the driven snow’ to highly saline or otherwise contaminated; in some environments both the amount and the quality of water change markedly from time to time. The biological adaptations to the available water supply are necessarily also quite varied and include such extreme examples as the kangaroo rat in the southwestern deserts, the lungfish in the ephemeral streams of east Africa, and the brine shrimp in Great Salt Lake.
Multivariate statistical methods in hydrology—A comparison using data of known functional relationship
Authors: Wallis James R.
Published: February 2008

Conventionally hydrologists have used regression analysis for solving their multivariate problems. Recently other multivariate statistical methods have been advocated. This paper discusses and compares the effectiveness of six methods of analysis: regression, principal component, varimax, oblimax, key cluster, and object. Strengths and weaknesses of each method are discussed, and the combination of principal component regression with varimax rotation of the factor weight matrix is recommended for an initial analysis of multifactor hydrologic problems.