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

1857 ◽  
Vol 8 ◽  
pp. 314-315
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Diurnal Variations ◽  
Horizontal Component ◽  
The Moon ◽  
Magnetic Declination ◽  
Magnetic Variation ◽  
Imperial Academy ◽  
Academy Of Sciences

In a communication made to the Royal Society in the last Session, “On the Lunar-diurnal Magnetic Variation at Toronto,” the author had stated that he could discover no trace of the lunar influence of the decennial inequality which constitutes so marked a feature in the solar magnetic variations. He has since read, in a memoir communicated to the Imperial Academy of Sciences at Vienna, entitled “On the Influence of the Moon on the horizontal component of the Mag­netic Force,” that M. Kreil is of opinion that the observations of different years at Milan and Prague, when combined, would rather favour the contrary inference, viz. that the decennial inequality exists in the lunar as well as in the solar variations.

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 On the meteorological observations made at the apartments of the Royal Society, during the year 1827, 1828, and 1829

1837 ◽  
Vol 3 ◽  
pp. 42-43
Keyword(s):  
Royal Society ◽  
Limited Range ◽  
Diurnal Variations ◽  
The Moon ◽  
French Academy ◽  
Annual Variations ◽  
The Mean ◽  
Meteorological Observations ◽  
Academy Of Sciences

The author first inquires into the annual and diurnal variations of the barometer and thermometer, for the determination of which he takes the mean of the observations in each month made at the Apartments of the Royal Society, during the years 1827,1828, and 1829; and also that deduced from Mr. Bouvard’s observations, published in the Memoirs of the French Academy of Sciences. From the table given it would appear that the annual variations are independent of the diurnal variations. A much greater number of observations than we possess at present, made frequently and at stated times each day, are requisite before any very satisfactory conclusion can be deduced as to the influence of the moon on the fluctuations of the barometer. The author, however, has attempted the inquiry, as far as the limited range of the present records will allow, by classifying all the observed heights, corresponding to a particular age of the moon, as defined by her transit taking place within a given half hour of the day; and thence deducing mean results, which are exhibited in tables. The results afforded by the observations at Somerset House differ widely from those obtained from corresponding observations made at the Paris Observatory. According to the former, the barometer is highest at new and full moons, and lowest at the quadratures the extent of the fluctuations being 0.08 of an inch: according to the lottery the controly is the esse, and the extent is only 0.05 of an inch.

scholarly journals XIX. The Bakerian Lecture.—On the influence of the moon on the magnetic declination at toronto, St. Helena, and Hobarton

1853 ◽  
Vol 143 ◽  
pp. 549-559 ◽  
Keyword(s):  
The Moon ◽  
Magnetic Declination ◽  
Suitable Arrangement ◽  
Imperial Academy ◽  
St Helena ◽  
Academy Of Sciences ◽  
Magnetic Needle

The success which attended the endeavour to detect the influence of the moon on the pressure of the atmosphere, by a suitable arrangement of the hourly barometrical observations at St. Helena, naturally suggested the idea that the influence of the moon on the direction of the magnetic needle, supposing such an influence to exist, might be manifested by an analogous arrangement of the hourly magnetical observa­tions at that station; inasmuch as the magnetical disturbances due to other causes, and liable to mask so small an effect as that which might be anticipated from the moon, were, like those of the barometer, of inconsiderable amount at St. Helena when compared with those at many other stations. An examination of observations of the Declination made at Milan, whilst M. Kreil was Director of that observatory, led him, in a memoir read in February 1841 to the Royal Bohemian Society of Sciences, to announce his belief that the moon does actu­ally exercise an influence on the magnetic direction at the surface of our globe, cognisable by a variation in the Declination depending on the moon’s hour-angle, and completing its period in a lunar day. M. Kreil has since confirmed the discovery thus announced by investigations based on a more extensive series of similar obser­vations made under his direction at Prague, and discussed,— 1st, in the 'Magnetische und Meteorologische Beobachtungen zu Prag’ for 1841; and 2nd, in a memoir pre­sented to the Imperial Academy of Sciences at Vienna in June 1850, and published in the Transactions of that Academy in 1852.

XXII. On the lunar-diurnal magnetic variation at Toronto

1856 ◽  
Vol 146 ◽  
pp. 499-506 ◽  
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Magnetic Force ◽  
Normal Values ◽  
Diurnal Variations ◽  
Total Force ◽  
Vertical Force ◽  
Uniform Temperature ◽  
Solar Time ◽  
Magnetic Variation

In fulfilment of an intention expressed to the Royal Society in November 1853, I have now the honour to submit to the Society the results of an investigation into the Moon’s diurnal influence on the horizontal and vertical components of the magnetic force at Toronto, and the consequent deduction of the Lunar-diurnal Variations of the Inclination and of the Total Force at that Station. The processes to which the observations of the Bifilar and of the Vertical force Magnetometers, as received from Toronto, were subjected after their arrival at Wool­wich, with a view to this and to other investigations, have been already partially described in a communication presented to the Society in a former part of the present Session. The processes there described had reference particularly to the reduction of the observations to a uniform temperature of the magnets employed to measure the variations of the respective components of the force,—to the elimination of the larger disturbances,—to the formation of normal values (omitting the disturbances) for each of the components at every hour of mean solar time for periods usually of a month’s duration,—and to the deduction of the solar-diurnal variation in different years and different months, after the larger disturbances had been eliminated.

I. On the lunar variations of magnetic declination at Bombay

1872 ◽  
Vol 20 (130-138) ◽  
pp. 135-136
Keyword(s):  
Diurnal Variation ◽  
Relative Position ◽  
Diurnal Variations ◽  
The Sun ◽  
The Moon ◽  
Feature Correspondence ◽  
Magnetic Declination ◽  
Variation Curve ◽  
Ordinary Character ◽  
The Mean

This paper is in continuation of that “On the Solar Variations of Magnetic Declination at Bombay,” published in the Philosophical Transactions for 1869; but the discussion is confined to the observations of the years 1861 to 1863, which alone have as yet been reduced. The point of principal interest brought out in the discussion is that whilst the mean lunar-diurnal variation is of the ordinary character, having as its principal feature a double oscillation in the lunar day, its range is very small as compared with the several ranges of the lunar-diurnal variations when the sun and moon have several specific varieties of relative position; and moreover, although in those latter variations the double oscillation is generally preserved as a main feature, correspondence of phase in the representative curves is as generally absent; and in some cases the curves are, whilst systematic, altogether different in character from the mean lunar-diurnal variation curve. The semiannual inequality in the lunar-diurnal variation, whilst it is as definitely systematic, has twice the range of the mean lunar, diurnal variation; and it is also subject to remarkable modifications which accompany changes of phase of the moon.

scholarly journals X. Note on the lunar-diurnal variation of magnetic declination

1868 ◽  
Vol 16 ◽  
pp. 59-60
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Diurnal Variations ◽  
Magnetic Equator ◽  
The Other ◽  
The Sun ◽  
Magnetic Declination ◽  
Royal Society Of London

I received late last night No. 91 of the Proceedings of the Royal Society, and desire to offer the following remarks on the abstract of a paper by Mr. Neumayer which I find therein (vol. xv. p. 414). Mr. Neumayer is evidently unacquainted with the Note by me, read to the Royal Society of London in 1861 (Proc. Roy. Soc. vol. x. p. 475), in which I stated as result of the discussions of five years’ observations at Trevandrum (near the magnetic equator) that the lunar-diurnal variation of magnetic declination became inverted, like the solar-diurnal variation, when the sun passed from one hemisphere to the other, both the solar- and lunar-diurnal variations depending on the position of the sun.

3. On the Lunar Diurnal Variation of Magnetic Declination at Trevandrum, near the Magnetic Equator

1872 ◽  
Vol 7 ◽  
pp. 756-758
Author(s):  
J. A. Broun
Keyword(s):  
Diurnal Variation ◽  
Diurnal Variations ◽  
Magnetic Equator ◽  
Magnetic Declination ◽  
The Law ◽  
The Times

The author gives the results derived from different discussions of nearly eighty thousand observations, made hourly during the eleven years 1854 to 1864. They are as follows:—1. That the lunar diurnal variation consists of a double maximum and minimum in each month of the year.2. That in December and January the maxima occur near the times of the moon's upper and lower passages of the meridian; while in June and July they occur six hours later, the minima then occurring near the times of the two passages.3. The change of the law for December and January to that for June and July does not happen, as in the case of the solar diurnal variations, by leaps in the course of a month (those of March and October), but more or less gradually for the different maxima and minima.

scholarly journals II. On the lunar diurnal variation of magnetic declination at the magnetic equator

1860 ◽  
Vol 10 ◽  
pp. 475-484
Keyword(s):  
Diurnal Variation ◽  
Careful Consideration ◽  
Magnetic Equator ◽  
Careful Examination ◽  
The Sun ◽  
The Moon ◽  
Magnetic Declination ◽  
The Law

This variation, first obtained by M. Kreil, next by myself, and afterwards by General Sabine, presents several anomalies which require careful consideration, and especially a careful examination of the methods employed to obtain the results. The law obtained seems to vary from place to place even in the same hemisphere and in the same latitude, and this to such an extent, that, for example, when the moon is on the inferior meridian at Toronto it produces a minimum of westerly declination; while for the moon on the inferior meridian of Prague and Makerstoun in Scotland it produces a maximum of westerly declination. No two places have as yet given exactly the same result; though the result for each place has been confirmed by the discussion of different periods. In order to obtain the lunar diurnal action, it has been usual to consider the magnetic declination at any time as depending on the sun’s and moon’s hour-angles and on irregular causes. Thus, if at conjunction, H 0 be the variation due to the sun on the meridian, and h 0 be that due to the moon on the meridian, H, the variation for the sun at 1 h , h 1 for the moon on the meridian of 1 h , and so on; it is supposed that we may represent the variations for a series of days by the following expressions, where the nearest values of h to the whole hour-angles are given:-

scholarly journals II. The diurnal variations of the wind and barometric pressure

1877 ◽  
Vol 25 (171-178) ◽  
pp. 402-411
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Barometric Pressure ◽  
Diurnal Variations ◽  
The Self ◽  
Diurnal Wind ◽  
Wind Currents ◽  
Remarkable Manner

In a paper which was read before the Royal Society in 1873, and which was honoured with a place in the 'Philosophical Transactions' of that year, I discussed the diurnal variations of the wind and barometric pressure at Bombay, and deduced therefrom the fact that a system of diurnal wind-currents moves synchronally with the diurnal variation of barometric pressure. Reasons, were given for believing that that system of diurnal wind-currents is a universal phenomenon; and on that hypothesis I showed how the diurnal variations of the barometer could be explained as a result of those currents. I have lately examined closely the “Discussion of the Anemometrical Results furnished by the self-recording Anemometer at Bermuda,” which forms Appendix II. of the ‘Quarterly Weather-Report of the Meteorological Office, London,’ July to September 1872. Those results support the conclusions arrived at in my former paper in such a remarkable manner as to justify the readvancement of some of them in a form which will prominently exhibit their relation to the diurnal variation of the barometer.

scholarly journals On the diurnal variation of the magnetic declination of St. Helena

1851 ◽  
Vol 5 ◽  
pp. 664-664
Keyword(s):  
Diurnal Variation ◽  
Northern Hemisphere ◽  
Opposite Direction ◽  
Diurnal Variations ◽  
The Sun ◽  
The Earth ◽  
Magnetic Declination ◽  
St Helena ◽  
Magnetic Needle

It has long been known that the diurnal variation of the magnetic needle is in an opposite direction in the southern, to what it is in the northern hemisphere; and it was therefore proposed as a pro­blem by Arago, Humboldt and others, to determine whether there exists any intermediate line of stations on the earth where those diurnal variations disappear. The results recorded in the present paper are founded on observations made at St. Helena during the five consecutive years, from 1841 to 1845 inclusive; and also on similar observations made at Singapore, in the years 1841 and 1842; and show that at these stations, which are intermediate between the northern and southern magnetic hemispheres, the diurnal variations still take place; but those peculiar to each hemisphere prevail at opposite seasons of the year, apparently in accordance with the position of the sun with relation to the earth’s equator.

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