Cheltenham Magnetic Observatory Research Articles

Magnetic storm of October 14–16, 1926, as recorded at the Cheltenham Magnetic Observatory

(Greenwich Civil Mean Time.)The principal portion of the storm began at 21h, October 14, and ended at 5h, October 16. From 17h to 21h on October 15 the motion of the magnets was so rapid that only at turning and halting points was a legible record made on the magnetogram. This was the period during which there was interference with the operation of telegraph lines. The amplitudes of the variations were as follows: Declination, 57′.1; horizontal intensity, 419γ; vertical intensity, about 730γ; (the Z spot went below the limits of the paper twice between 7h and 9h on October 15.)

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July to September, 1926

(Lat. 38°44′.0N.: long. 76°50′.5 or 5h07m,4 W. of Gr.)

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, April to June, 1926

(Lat. 38° 44′.0 N.; long., 76° 50′.5, or 5h 07.4mW. of Gr.)

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, January to March, 1926

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

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July to December, 1925

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

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, January to June, 1925

(Latitude, 38° 44′.0N; Longitude, 76° 50′.5, or 5h07m.4 W. of Greenwich.)

Principal magnetic storms at the Cheltenham Magnetic Observatory, October to December, 1924

The only notable magnetic disturbance during the quarter was that beginning October 23 at 17h G.M.T. and ending October 24 at 11h G.M.T., with ranges as follows: Declination, 25′.6; horizontal intensity, 119γ; vertical intensity, 113γ.

Principal Magnetic Storms recorded at the Cheltenham Magnetic Observatory, April to September, 1924

(Latitude, 38° 44′.0 N.; Longitude, 76° 50′.5, or 5h 07.m4 W. of Greenwich.)

Principal magnetic storms at the Cheltenham Magnetic Observatory, January 1 to March 31, 1924

Principal magnetic storms at the Cheltenham Magnetic Observatory, January 1 to March 31, 1924

The Aurora Borealis of March 22–23, 1920, as seen at the Cheltenham Magnetic Observatory

Another magnetic storm of extraordinary magnitude was recorded on March 22–23, 1920, at the magnetic observatory of the United States Coast and Geodetic Survey, Cheltenham, Maryland, latitude 38° 44′.0 N., longitude 76° 50′.5 W. Its chief features are described in Mr. Hazard's article, pages 57–59. There was no recurrence of the storm 27 days later, April 19–20.The Aurora was visible soon after sunset on March 22, 1920, but was first noticed by the writer at 8h 05m 75th meridian time. At 8h 10m a display of rays developed, proceeding from a bright band low in the northern horizon some 45° in extent. The rays were visible from a point in the western horizon a few degrees (5°–10°) N. of the new moon (azimuth from S ‐ 88°) to a few degrees in the eastern horizon east of Arcturus (azimuth = −76°.0), and apparently converged to a few degrees north of the planet Jupiter (azimuth 26.5 and altitude 68°.5). There was a conspicuously rosy colored ray in the east. The rays lasted for about 5 minutes. The boundary of the illuminated area was parabolic in form. The ray display was followed by a general diffused glow.

The magnetic storm of August 11–12, 1911, as observed at the Cheltenham Magnetic Observatory

A magnetic storm of extraordinary magnitude occurred on August 11, 1919, at the magnetic observatory of the United States Coast and Geodetic Survey, latitude 38° 44′ N. and longitude 76° 50′.5 W. It began abruptly at 1h 58m 75th meridian time, A.M., August 11. The first movement in declination (D), was from 6° 18′.9 W to 6° 14′.9 W, followed by a sudden change to 6° 37′ W. The recording spot left the sheet at 2h 56m, at the value 7° 18′ W. and returned at 3h 28m, the maximum having occurred during this interval, probably reaching 7° 38′ W.

Activity of the Earth's magnetism

At the request of the International Commission for Terrestrial, Magnetism, the “activity” of the Earth's magnetism has been computed for each day of the year 1915 from the records of the Cheltenham Magnetic Observatory, using the method proposed by the late Dr. Bidlingmaier and explained by him in the publication of the results of the Wilhelmshaven observations for 1911.This method takes the variability of the Earth's magnetism as a measure of its activity, that is, its departure, from moment to moment, from its undisturbed state. As we have not as yet data for determining this undisturbed state, the activity for a day is derived from the departures from the daily mean. This is divided into two parts, namely: the departure of the hourly means from the daily mean and the departure of the individual values in each hour from the mean value for that hour.

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July 1 to September 30, 1914

For the last quarter of 1913 Cheltenham reports “No storms during this period,” and Tucson reports “A period free from pronounced disturbances.”

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, January 1 to June 30, 1914

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, January 1 to June 30, 1914

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, July 1 to December 1, 1913

For the last quarter of 1913 Cheltenham reports “No storms during this period,” and Tucson reports “A period free from pronounced disturbances.”

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory, October 1 to December 31, 1912

Not alone in the duties and observations of the positions occupied by Messerschmitt did his ability and energy show themselves. He belonged to many societies and organizations, in all of which he took a very active and prominent part, as treasurer, secretary, or as an active committee member. He is author of numerous publications, both scien‐ tific and popular. Whatever he undertook received his devoted care and unceasing enthusism.1

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory

Principal magnetic storms recorded at the Cheltenham Magnetic Observatory

Magnetic character of days as observed at the Cheltenham Magnetic Observatory, April 1 to June 30, 1912, G. M. T.

Magnetic character of days as observed at the Cheltenham Magnetic Observatory, April 1 to June 30, 1912, G. M. T.

On the moment of inertia of long magnet H26 at the Cheltenham Observatory

On pages 45–46 of the March 1912 number of this Journal, attention was called to the difference between the values of the moment of inertia of a magnet as computed from its dimensions and mass, and as determined experimentally with the aid of an auxiliary inertia weight, and the statement was made that in each of the four cases mentioned where such differences were shown the magnet house of the magnetometer used was of brass, so that any effect due to impurity or damping might affect the experimentally determined results.At the suggestion of the Editor of this Journal it was decided to test this matter experimentally for the long magnet of Magnetometer No. 26, the standard instrument of the Cheltenham Magnetic Observatory.