scholarly journals On the height of the Aurora Borealis above the surface of the Earth; particularly one seen on the 29th of March, 1826

1833 ◽  
Vol 2 ◽  
pp. 342-344 ◽  
Keyword(s):  
Scientific Journals ◽  
Apparent Position ◽  
Aurora Borealis ◽  
Far North ◽  
The North ◽  
The Earth ◽  
East And West ◽  
Magnetic Meridian ◽  
North And South

The author observes that opinions differ as to the elevation of the Aurora Borealis above the surface of the earth, and that this is a point which can be determined only by a series of concurring observations. The appearance of a phenomenon of this kind on the 29th of March, 1826, assuming the form of a regular arch at right angles to the magnetic meridian, and marked by peculiar features, continuing for above an hour in the same position, afforded a most favourable opportunity for obtaining the data requisite for the solution of this problem; and the author accordingly took great pains to collect as many authentic accounts as possible of the apparent position of this luminous arch with reference to the stars, when seen from various places where it had been observed in England and in Scotland. It appears to have been actually seen in places 170 miles distant from one another, in a north and south direction, and 45 miles distant from east to west, thus comprising an area of 7000 or 8000 square miles; but it must have been visible over a much greater extent. Accounts were received of its having been seen as far north as Edinburgh, and as far south as Manchester and Doncaster, and at most of the intermediate towns; and from the exact; correspondence of the descriptions from all these places, it was impossible to doubt that they referred to the same luminous appearance. In proceeding from north to south, the apparent altitude of the arch continually increased, still keeping to the south of the zenith till we come to Kendal, at which place it very nearly crossed the zenith; at Warrington, which is further south, the culminating point of the arch was north of the zenith. Wherever seen, the arch always seemed to terminate nearly in the magnetic, east and west, at two opposite points of the horizon. The observations, in which the author places the greatest confidence for determining the height of this aurora, were those made at Whitehaven and at Warrington, places which are distant 83 miles from one another, and situated nearly on the same magnetic meridian. Calculating from the data they afford, he finds the height of the arch very nearly 100 miles above the surface of the earth, and immediately over the towns of Kendal and of Kirkby-Stephen. This conclusion is corroborated by observations at Jedburgh; but if the former be compared with those at Edinburgh, the height will come out to be 150 or 160 miles, and the position vertical about Carlisle: but he thinks the former result more entitled to confidence. Assuming the height to be 100 miles, it will follow that the breadth of the arch would be 8 or 9 miles, and its visible length in an east and west direction from any one place would be about 550 miles. The author then proceeds to take a comparative view of the results of inquiries on the height and position of other auroræ which have at different times appeared, and are recorded in the Philosophical Transactions and other scientific journals. He also gives an account of a luminous arch seen both at Kendal and at Manchester on the 27th of December last, which appeared in the zenith at the former place, and was elevated 53° from the north at the latter place; whence its height is deduced to be 100 miles. From the general agreement of this series of observations, the author infers that these luminous arches of the aurora, which are occasionally seen stretching from east to west, are all nearly of the same height; namely, about 100 miles. Observations are still wanting for the determination of the length of beams parallel to the dipping-needle, which constitute the more ordinary forms of the aurora borealis; neither can it be determined whether these beams arise above the arches, as from a base, or whether they descend below, as if appended to the arches. It is remarkable that the arches and beams are rarely, if ever, seen connected together, or in juxta-position; but always in parts of the heavens at a considerable distance from each other.

On the relative dynamic value of the degrees of the compass; and on the cause of the needle resting in the magnetic meridian.

1851 ◽  
Vol 5 ◽  
pp. 626-626
Keyword(s):  
Magnetic Compass ◽  
The South ◽  
The North ◽  
East And West ◽  
Magnetic Meridian ◽  
North And South

By ascertaining the distances at different azimuths at which a bar magnet placed with its axis directed to the centre of a magnetic compass needle caused the needle to assume the position in which its axis was in the same line with that of the magnet, the author found that these points of distance form a peculiar curve, which was nearest to the centre of the magnet at the east and west azimuths, and receded from it as it advanced to the north and south; and was twice the distance from it at the north than at the south azimuths.

DETERMINATION OF THE REPULSIVE FORCE OF A THICK HIGH-COERCIVE PERMANENT MAGNETS IN THE AXIAL BEARING OF A VERTICAL PUMP

2021 ◽  
pp. 23-27
Author(s):  
A. Ya. Krasil’nikov ◽  
A. A. Krasil’nikov
Keyword(s):  
Standard Method ◽  
Permanent Magnets ◽  
Magnetic System ◽  
Repulsive Force ◽  
Cobalt Alloy ◽  
Average Value ◽  
The North ◽  
Repulsive Forces ◽  
North And South

The article considers the possibility of applying a standard method for calculating the repulsive force for a thick high-coercive permanent magnets from samarium-cobalt alloy in a magnetic system. The results of the research allowed us to introduce correction coefficients in the method of calculating the repulsive force in a magnetic system with such magnets, depending on the air gap between of them. It is shown that the repulsive forces of the North poles of permanent magnets differ from the repulsive forces of the South poles. The research was carried out with magnets manufactured by different enterprises. When calculating the repulsive force, the average value of the repulsive force between the North and South poles of magnets is found.

scholarly journals Ships and their timber source as indicators of connections between regions

AmS-Skrifter ◽  
2020 ◽  
pp. 133-143
Author(s):  
Aoife Daly
Keyword(s):  
Western Europe ◽  
The Baltic Sea ◽  
The North ◽  
Baltic Coast ◽  
Art Objects ◽  
The North Sea ◽  
The Baltic ◽  
North And South ◽  
North Western

The precise dating and determination of the source of timbers in shipwrecks found around the coasts of the North Sea and the Baltic Sea, through dendrochronology allows us to see connections between north and  south, east and west throughout the region and to a high chronological precision. In this paper we take a look at results of recent analyses of timber from ships, and timber and barrel cargoes, to try to draw a chronological picture, from the twelfth to seventeenth centuries, of links between regions, through transport in oak ships and trade of timber. Archaeological finds of oak from timber cargos in shipwrecks and fine art objects (painted panels and sculpture) show the extent to which timber was shipped from Hanseatic towns along the southern Baltic coast, to western and north-western Europe.

scholarly journals On the variable intensity of ter­restrial magnetism, and the influence of the aurora borealis upon it

1837 ◽  
Vol 3 ◽  
pp. 37-38
Keyword(s):  
Magnetic Force ◽  
The Sun ◽  
South Pole ◽  
Variable Intensity ◽  
Aurora Borealis ◽  
The North ◽  
The Earth ◽  
Northern Latitudes ◽  
Snow Storms ◽  
Magnetic Needle

The author gives the results of a series of observations on the vibrations of the magnetic needle, which he undertook last summer, for the purpose of ascertaining whether the intensity of its directive force is affected by the changes in the earth’s distance from the sun, or by its declination with respect to the plane of its equator. He observed that the magnetic intensity is subject to frequent variations, which are sometimes sudden, and of short duration. These anomalies he has been unable to refer to any obvious cause, except when they were accompanied by the appearance of the aurora borealis, which evidently affected the needle on many occasions. He also thinks that the vibrations of the needle became less rapid with a moist atmosphere, and more so when it was very dry. Changes of the wind and snow storms appeared also to be attended with fluc­tuations in the intensity of the magnetism. He endeavoured to ascertain whether there existed any decided and constant difference in the directive force of each pole; conceiving that, on the hypothesis of a central magnetic force, the north pole of the magnet would, in these northern latitudes, be acted upon with much greater energy than the south pole. From his observing that the relative intensity of the two poles is not always the same, he infers the probability of the earth’s magnetism being derived from the agency of electric currents existing under its surface as well as above it, and that the rapid fluctuations in its intensity are owing to meteorological changes. The author is led to conclude that the aurora borealis is an elec­trical phenomenon, and that it usually moves during the night nearly from north to south, and in an opposite direction during the day ; that it is of the nature of positive electricity; and that its elevation above the earth is much greater than a thousand, and perhaps thou­sands of miles.

An account of the aurora borealis of the 17th of November 1848

1851 ◽  
Vol 5 ◽  
pp. 809-811
Keyword(s):  
The Moon ◽  
The South ◽  
Aurora Borealis ◽  
North East ◽  
The North ◽  
Northern Half ◽  
East And West

The author states that, “About half-past 7 p. m. the sky assumed the appearance which it usually does immediately preceding the action of what are called the Northern Lights. In the northern half it was quite clear for about forty-five degrees from the meridian, of a pale blue, and covered with a faint light, such as generally ushers in the moon at her rising. Towards the east and west this light gradually diminished, and south of those cardinal points the dimness as gradually thickened. “Soon after eight the coruscations began by the usual lambent strokes of a shining filmy matter, like the sudden shooting forth and instantaneous retroceding of a serpent’s tongue. They commenced in the north-east, and shot upwards in an angle of about 70 degrees of inclination towards the south, and to about 60 degrees in length, more or less, leaving the sky clear to the north, and in a manner gradually chasing the clouds, upon whose receding bounds they glanced further to the south.

On the position of the north magnetic pole

1837 ◽  
Vol 3 ◽  
pp. 254-254 ◽  
Keyword(s):  
Vertical Position ◽  
Magnetic Pole ◽  
The North ◽  
The Earth ◽  
North Magnetic Pole ◽  
To Come ◽  
Magnetic Poles ◽  
Magnetic Needle ◽  
Made In

The author remarks that the discordances in former observations made with a view to determine the position of the magnetic pole, have arisen partly from the irregularity of distribution in the earth of the substances which exert magnetic power, and partly from the great distances from the magnetic poles at which these observations have been made. The latter cause of uncertainty has been now, in a great measure, removed, by the numerous and accurate observations made during the late arctic expeditions. The object of the present paper is to put on record those which were made in the last voyage of Captain Ross, in which a spot was reached corresponding to the true north magnetic pole on the surface of the earth. The nature of the instruments, and the difficulties encountered in their practical employment, under the circumstances of the expedition, are fully stated. Having arrived, on the 1st of June, at north latitude 70° 5' 17", and west longitude 96° 45' 48", the horizontal magnetic needle exhibited no determinate directive tendency, and the dipping needle was within a minute of the vertical position, a quantity which may be supposed to come within the limits of the errors of observation; hence the author concludes that this spot may be considered as the true magnetic pole, or as a very near approximation to it, as far, at least, as could be ascertained with the limited means of determination of which he was then in possession. A table of the observations, including those on the intensity of the magnetic force at various stations, is subjoined.

scholarly journals On the aurora borealis which occurred on the evening of Friday, the 17th of November, 1848

1851 ◽  
Vol 5 ◽  
pp. 790-792
Keyword(s):  
White Light ◽  
Northern Region ◽  
The South ◽  
North West ◽  
Aurora Borealis ◽  
North East ◽  
The North ◽  
Short Period ◽  
The Hours ◽  
Magnetic Meridian

The author states that the 17th of November was a fine day with a clear sky and bright sunshine: towards evening the sky became cloudy and a few drops of rain fell, but it soon again became clear, with the exception of a few fleecy clouds that here and there dimmed its brightness. At 6 h 45 m a soft and gentle light began to illumine the northern region of the sky; and at 7 o’clock a considerable portion of it was covered with dark-red streams of light towards the east; while streamers moving to and fro, arrayed in colours of golden and silvery hues, overspread the south and north. About 8 o’clock there appeared near the zenith, and upon the magnetic meridian, a ring of an elliptical form, from which proceeded in all directions towards the horizon, beams or columns of light, giving to the heavens the appearance of a splendid vault, with its top adorned with a crown or wreath; while around and within the vault were to be seen clouds of brilliant light flashing towards and from the crown or central circle of the aurora, sometimes tinged with prismatic rays, at other times intensely white and lucid. About half-past nine nearly the whole of the aerial canopy was clad with clouds of a bright red colour, casting a curious reddened hue over the objects on the surface of the earth. After a short period of time had elapsed, the red colour began to diminish in intensity, and was again replaced by the white dome. However, in various parts of the sky the red colour still remained, principally in the north-west, southwest, and north-east. Between the hours of twelve and one beams of brilliant white light commenced shooting up in the south from the horizon to the central ring or pole. The beams appeared to be at nearly equal distances from each other, the entire column of them stretching over a space equal to about one-fifth part of the visible horizon, in the form of a fan. The whole figure rapidly changed from a pure white light into a glow of brilliant colours of every tint, variegating the undulating waves as they rolled on their way to the pole of the aurora. In the course of three minutes these gave place to the white flashing radiations. During the time of the aurora there were a great number of small meteors, the direction of whose motion was from east to west, and which appeared to be considerably below the sphere of the aurora.

The Excavation of Kindrochit Castle, Aberdeenshire

1928 ◽  
Vol 8 (1) ◽  
pp. 69-75
Author(s):  
W. Douglas Simpson
Keyword(s):  
The Other ◽  
Blind Alley ◽  
The North ◽  
Strong Position ◽  
East And West ◽  
North And South

The ruins of Kindrochit Castle stand in the heart of the much-frequented village of Braemar, near the head of the river Dee, amid the wild mountains of western Aberdeenshire. The castle occupies a very strong position on the east brink of a rocky gorge formed by the Clunie Water, and on the other side was defended by an ancient mill-lade, taken off the Clunie above the castle, and rejoining it below, so as to complete the insulation of the site. In the name of the castle (Kindrochit = ‘bridge-head’) is enshrined its early importance as a fortified post guarding the passage of the great north road across the Clunie Water. The map (fig. 1) clearly indicates how the significance of the castle is to be found not in the east-and-west or blind-alley strategy of the Dee valley, but rather in the north and south or transversal strategy of the ancient trunk roads converging northwards across the ‘Mounth’ or mountain barrier between Strathmore and Mar.

scholarly journals Determination of clay minerals using gamma ray spectroscopy for the Zubair Formation in Southern Iraq

2021 ◽  
Author(s):  
Methaq K. Al-Jafar ◽  
Mohanad H. Al-Jaberi
Keyword(s):  
Clay Minerals ◽  
Gamma Ray ◽  
Oil Reserves ◽  
The North ◽  
North Part ◽  
Sandstone Formation ◽  
Cretaceous Period ◽  
The Relationship ◽  
North And South

AbstractSandstone oil reserves are composed of a variety of clay minerals, including kaolinite, illite, and chlorite. These clay minerals have a significant effect of reservoir quality. The upper sandstone member (USS) of Zubair Formation is the most plentiful reservoir of the field and it’s part of a large anticline that belongs to an enormous clastic sandstone formation, from the Lower Cretaceous period. A spectral gamma-ray (SGR) log was used to identify the type of clay minerals, depositional environment, and the relationship between total organic matter with uranium concentration. SGR log indicated that USS is composed mainly of chlorite, smectite, and illite clay minerals with the presence of kaolinite as a dominant clay mineral component. Th/U ratio varies between 2.55 and 8.52 and 1.11 to 11.68 in the north and south parts of the field, respectively. The USS had a fluvially dominated, sand-rich deltaic environment based on the Th/U ratio. Furthermore, Th/K cross-plot was found that the south part was more affected by illite compared with the north part, although the presence of kaolinite.

Surveying terrestrial magnetism in time and space

2005 ◽  
Vol 32 (2) ◽  
pp. 346-360 ◽  
Author(s):  
Anita McConnell
Keyword(s):  
Polar Regions ◽  
Horizontal Force ◽  
Magnetic Pole ◽  
Compass Direction ◽  
The North ◽  
Magnetic Variation ◽  
Magnetic Meridian ◽  
Magnetic Poles ◽  
North And South ◽  
Over Time

Charts marked with the lines of magnetic variation have been published since Halley's Atlantic chart of 1701. It was already known that the location of the magnetic poles shifted over time, and that the north and south poles were not diametrically opposite. As more seafarers penetrated the Southern Ocean, isogons on the charts were extended southwards with greater confidence. At sea variation was measured by comparing compass direction with the Sun's midday shadow. In polar regions, where horizontal force is too weak to attract a compass needle, the location of the pole was sought by observing the inclination of a dip needle swinging in the magnetic meridian, which would hang vertically at the pole. The Fox dip circle, developed in 1834, was the first instrument capable of measuring dip and intensity at sea, and allowed James Clark Ross to predict the location of the South Magnetic Pole. In 1902 Discovery's crew landed an observatory ashore, but a trek on to the plateau failed to reach the magnetic pole. Success came in 1909 during Shackleton's Nimrod expedition, when T. Edgeworth David's party reached the zone of maximum dip. Over the following years data from photographic magnetometers recording declination, vertical and horizontal intensity were routinely made at the various national bases round Antarctica; they contributed to our knowledge of the Earth's internal magnetism and on the solar influences.

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