scholarly journals II. On a supposed periodicity in the elements of terrestrial mag­netism, with a period of 26 1/3 days

1872 ◽  
Vol 20 (130-138) ◽  
pp. 308-312 ◽  
Keyword(s):  
The Sun ◽  
Horizontal Force ◽  
Magnetic Elements ◽  
Royal Observatory ◽  
Imperial Academy ◽  
Meteorological Observations ◽  
Academy Of Sciences ◽  
Periodical Change

In a paper published in the ‘Proceedings of the Imperial Academy of Sciences of Vienna,’ vol. lxiv., Dr. Karl Hornstein has exhibited the results of a series of observations which appeared to show that the earths magnetism undergoes a periodical change in successive periods of 26 1/3 days, which might with great plausibility be referred to the rotation of the sun. It appeared to me that the deductions from the magnetic observations made at the Royal Observatory of Greenwich, and which are printed annually in the Greenwich Observations,’ or in the detached copies of ‘Results of Magnetical and Meteorological Observations made at the Royal Observatory of Greenwich, would afford good materials for testing the accuracy of this law, as applicable to a series of years. The mew results of the measured hourly ordinates of the terrestrial magnetic elements are given for every day, and it is certain that there has been no change of adjustments of the declination and horizontal-force instruments in the course of each year. For the horizontal-force instrument the temperature of the room has been maintained in a generally equable state, and in later years it has been remarkably uniform.

scholarly journals III. On a periodic change of the elements of the force of terrestrial magnetism discovered by Professor Hornstein

1872 ◽  
Vol 20 (130-138) ◽  
pp. 21-21
Keyword(s):  
Periodic Change ◽  
The Sun ◽  
Horizontal Force ◽  
Terrestrial Magnetism ◽  
Imperial Academy ◽  
Academy Of Sciences

Professor Hornstein, of Prague, has communicated to the Imperial Academy of Sciences of Vienna a paper entitled “On the dependence of the Earth’s Magnetism on the Rotation of the Sun.” He shows that the changes of each of the three elements of the force of terrestrial magnetism (declination, inclination, and horizontal force) indicate a period of 26 1/3 days. The periodic change of declination for Prague (1870) amounts to 0.705 sin ( x + 190° 20'), where x = 0° at the commencement of 1870, and x = 360° at the commencement of 1871. For Vienna the range is a little larger. The range of inclination is nearly one-third of that of declination, that of the intensity nearly 24 units of the 4th decimal (the intensity in June 1870 was nearly 2.0485).

scholarly journals I. On the evidence of the existence of the decennial inequality in the solar-diurnal magnetic variations, and its non-existence in the lunar-diurnal variation, of the declination at Hobarton

1857 ◽  
Vol 147 ◽  
pp. 1-8 ◽  
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Magnetic Elements ◽  
Imperial Academy ◽  
The Subject ◽  
British Colonial ◽  
The Mean ◽  
Hourly Observation ◽  
Academy Of Sciences ◽  
Magnetic Observatories

In a report presented to the British Association at Liverpool in September 1854, entitled "On some of the results obtained at the British Colonial Magnetic Observatories," I stated that, as far as my examination of the observations had then gone, I had found in the Lunar-diurnal magnetic variation no trace of the decennial period which is so distinctly marked in all the variations connected with the Sun. And in a subsequent communication to the Royal Society in June 1856, “On the Lunar-diurnal Variation at Toronto,” in which the moon’s influence on each of the three magnetic elements was examined, the conclusion arrived at was to the same effect, viz. that the observations at Toronto “showed no appearance of the decennial period which constitutes so marked a feature in the solar-diurnal variations.” Since these statements were made, I have read M. Kreil’s memoir “On the Influence of the Moon on the horizontal component of the Magnetic Force,” presented to the Imperial Academy of Sciences at Vienna in 1852 and printed in 1853, from which I learn (pp. 45, 46) that M. Kreil is of opinion that the observations of different years at Milan and Prague, when combined, would rather favour the supposition that the same decennial period which exists in the solar variation affects also the lunar magnetic influence. The question is one of such manifest importance in its theoretical bearing, that I considered it desirable to lose no time in re-examining it by the aid of the Hobarton observations, which, as it appeared to me, were particularly suitable for the purpose, inasmuch as they consist of eight consecutive years of hourly observation (from January 1841 to December 1848 inclusive), made with one and the same set of instruments, and by a uniform system of observation. The results of this examination have been, as it appears to me, so decidedly confirmatory of the conclusions drawn from the Toronto observations, both as regards the existence of the decennial period in the two classes of solar-diurnal variation (viz. in the mean diurnal variation occasioned by the disturbances of large amount, and in what may be termed the more regular solar-diurnal variation), and the non-existence of a similar decennial period in the case of the lunar-diurnal variation, that I have been induced to make these results the subject of a communication to the Royal Society.

scholarly journals L. Observations of the transit of Venus on June 3, 1769, and the eclipse of the Sun on the following day, made at Paris, and other places. Extracted from letters addressed from M. De la Lande, of the Royal Academy of Sciences at Paris, and F. R. S. to the Astronomer Royal; and from a letter addressed from M. Messier to Mr. Magalhaens

1769 ◽  
Vol 59 ◽  
pp. 374-377 ◽  
Keyword(s):  
Royal Academy ◽  
The Sun ◽  
Internal Contact ◽  
Royal Observatory ◽  
Academy Of Sciences

M. Messier, with the best achromatic telescope at Paris, of 12 feet focus, made by M. Antheaulme, observed the first internal contact at 7th 38' 43", apparent time reduced to the Royal Observatory, and, he thinks, without an uncertainty of two seconds: and this is the observation in which I most confide.

scholarly journals VIII. Magnetic survey of Belgium in 1871

1873 ◽  
Vol 163 ◽  
pp. 341-357
Keyword(s):  
Fixed Points ◽  
The Other ◽  
Magnetic Survey ◽  
Horizontal Force ◽  
The West ◽  
Magnetic Elements ◽  
Royal Observatory ◽  
Complete Series ◽  
The Subject ◽  
Made In

Previous to the year 1871 few observations had been made in Belgium for determining the elements of terrestrial magnetism, if we except the series which has been carried on without interruption at the Royal Observatory since 1828. Before this latter date the Intensity and Dip had never been ascertained, and there existed only two reliable measures of the Declination, viz. that of 20°35'·5 for Ostend, which Pigot observed in 1772, and the other for Nieuport, which, at about the same date, was found by Mann to be 19°48'·5. Since 1828 the observations made at any other station besides Brussels have not been numerous. In 1854 the Dip was measured at Antwerp, Courtray, Ghent, Mons, and Ostend; the Horizontal Force was found at Liége and Louvain in 1829, 1850, and 1854, and also at Namur in 1829; and the three elements were observed in 1859 at Ghent and Mechlin. The results of these various observations are collected in the work entitled “La Physique du Globe,” by M. A. Quetelet, and in Dr. Lamont’s 'Untersuchungen über die Richtung und Stärke des Erdmagnetismus in Belgien,’ &c. The above being the only determinations of the magnetic elements, there is an obvious want of a complete series of observations at a sufficient number of stations, and the survey which forms the subject of the present paper was undertaken with the view of supplying the required series of connected values of the three elements. The instruments employed in this survey were the Barrow dip-circle, the Jones unifilar, and the Frodsham chronometer of Stonyhurst Observatory, and an excellent theodolite by Troughton and Simms for determining the azimuth of the fixed points for the Declination. For this last instrument I was indebted to the kindness of James Shoolbred, Esq., C. E. All necessary information respecting the magnets and instruments will be found in the paper on the Magnetic Survey of the West of France printed in the Phil. Trans, of 1870.

The role of science in the study of and response to space threats

2019 ◽  
Vol 89 (8) ◽  
pp. 777-799
Author(s):  
B. M. Shustov
Keyword(s):  
Comparative Analysis ◽  
20Th Century ◽  
21St Century ◽  
Space Debris ◽  
The Sun ◽  
National Program ◽  
Biological Hazard ◽  
Academy Of Sciences ◽  
Space Activities

During the second half of the 20th century and the beginning of the 21st century, space hazards multiplied, the most urgent of which is space debris. Professionals working in space are exposed to this hazard daily and are aware of it as a problem. Furthermore, increasing attention is being paid to the unpredictable behavior of the Sun, which produces the so-called space weather. The asteroid-comet hazard is considered as potentially having the most catastrophic consequences. No manifestations of biological hazard have yet been observed, although as space activities develop, it is becoming increasingly important. The appropriate time scale for astrophysical hazards is many millions of years, so from a practical perspective, they have no importance. This article briefly describes the main types of space hazards. The author analyzes the results of research and practical work in the field, both worldwide and specifically in Russia. Comparative analysis leads to the clear conclusion that a national program must be developed for the study of space hazards and to respond to space threats. This article is based on a report made by the author at the meeting of the Presidium of the Russian Academy of Sciences (RAS) on January 15, 2019.

Rotation of the magnetic elements in polar regions on the Sun

2007 ◽  
Vol 328 (10) ◽  
pp. 1016-1019 ◽  
Author(s):  
E.E. Benevolenskaya
Keyword(s):  
Polar Regions ◽  
The Sun ◽  
Magnetic Elements

scholarly journals XXXIV. Observations on the transit of Ve­nus, June the 6th, 1761, made in Spital-Square; the longitude of which is 4' 11" west of the Royal Observatory at Green­wich, and the latitude 51° 31' 15" north

1761 ◽  
Vol 52 ◽  
pp. 182-183
Keyword(s):  
The Sun ◽  
Royal Observatory ◽  
The Mean ◽  
The Difference ◽  
Made In

Having measured the diameter of Venus, on the sun, three times, with the object-glass micrometer, the mean was found to be 58 seconds; and but 6/10 of a second, the difference of the extremes.

scholarly journals The astronomer - N. N. Donitch

2003 ◽  
pp. 71-77
Author(s):  
A.A. Baikov ◽  
A. Gaina
Keyword(s):  
English Translation ◽  
Main Part ◽  
History Of ◽  
Imperial Academy ◽  
Solar Eclipses ◽  
Academy Of Sciences

This paper describes a history of friendship and collaboration between the astronomers N. Donitch and A.A. Baikov. Information on other astronomers L.V. Okulitch and E.A. Von der Pahlen, and meteorologists V.H. Dubinskii and Nina Gouma, can also be found. Details on the expeditions aimed at observing the total solar eclipses on 30 August 1905 (organized by the Imperial Academy of Sciences in Sankt-Petersburg) and 19 June 1936 (organized by the Romanian Royal Cultural foundation) are given. The main part represents the first English translation of the paper by Baikov, published earlier in Russian and Romanian, with a new preface, annotations, and comments.

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