scholarly journals The Bakerian Lecture. An account of experiments to determine the amount of the dip of the magnetic needle London, in August 1821; with remarks on the instruments which are usually employed in such determinations

1833 ◽  
Vol 2 ◽  
pp. 155-156
Keyword(s):  
Nursery Ground ◽  
The North ◽  
The Subject ◽  
The Difference ◽  
Regent's Park ◽  
The Times ◽  
Magnetic Meridian ◽  
Magnetic Needle ◽  
Source Of Error ◽  
Made In

After describing the imperfections of the instruments in general use for ascertaining the dip of the magnetic needle, and adverting to the consequent inaccuracy and insufficiency of the observations made with them, Captain Sabine gives an account of the form of dipping-needle which he preferred for his experiments, and which was con­structed for him by Mr. Dollond, upon principles laid down by Pro­fessor Meyer, of Gottingen. He then enters into minute details of the mode of pursuing and verifying his observations, the results of which, gained by three different methods, are as follows: viz. by 10 experiments with Meyer’s needle, 70° 2'.9; by the times of oscil­lation in the magnetic meridian, and in the plane perpendicular to it (mean by three needles), 70° 04'; by the times of vertical and hori­zontal oscillation, 7° 02'.6. So that 70° 03' may be considered as the mean dip of the needle towards the north, in August and Sep­tember 1821, within four hours of noon, being the limit within which all the experiments were made. Alluding to former observations for the purpose of determining the dip in London, the author observes that, independent of any im­perfection in the instruments, they were made in houses in close built parts of the metropolis, and, therefore, all subject to the in­fluence of local attraction; and, moreover, that the correction found by observing the difference of the dip on the outside of the house cannot be regarded as an effectual remedy, inasmuch as the needle may still have been attracted by iron in the adjoining houses, or in the neighbourhood. It is, indeed, only requisite to try needles in different situations in a city, to be convinced how little dependence should be placed in the accuracy of such results: the author thinks that it is rather owing to this cause than to instrumental error, that the dip at the Apartments of the Royal Society is stated in the Phi­losophical Transactions for the present year to be 71° 06'. To avoid this source of error, Captain Sabine conducted the observations which form the subject of this lecture in the nursery-ground in the Regent’s Park, a situation which he regards in all respects eligible, and far removed from the influence of iron.

Barometrical observations, showing the effect of the direction of the wind on the difference between distant barometers

1843 ◽  
Vol 4 ◽  
pp. 386-387
Keyword(s):  
Atmospheric Pressure ◽  
The North ◽  
Heating And Cooling ◽  
Westerly Winds ◽  
Different Seasons ◽  
The Subject ◽  
The Difference ◽  
The Times ◽  
The One

The author institutes a comparison between the barometric heights as observed at the Apartments of the Royal Society, and at his house in Herefordshire, in the neighbourhood of Ross, with a view to ascertain the influence of prevailing winds on the atmospheric pressure. The barometers thus compared together were of the same construction, and by the same maker; and the times of observation, namely nine o’clock a. m. and three o’clock p. m., were the same at both places, the distance between which is 110 miles in longitude, and about 20 in latitude. The degree of accordance in the march of the two barometers is exhibited by that of curves traced on three sheets accompanying the paper. The results are given in eight tables. The author agrees with Schubler in ascribing the currents prevailing in the atmosphere to the variable relations of heating and cooling which obtains between the Atlantic Ocean and the continent of Europe at different seasons; the facts ascertained by the series of observations here presented being in accordance with that hypothesis. If the northerly and westerly winds in England be partly the effect of the expansion of the air on the continent, then the barometer which is nearest to the continent, or in this instance that at London, ought to be relatively more depressed than the one more distant; or if the southerly and easterly winds be regarded as proceeding to the ocean, then, for a similar reason, the barometer nearest to the ocean ought to be relatively depressed; and that both these effects are produced, is shown by the tables. This view of the subject also, the author remarks, is corroborated by Raymond’s observations, detailed in his memoir on the determination of the height of Clermont Ferrand, from which it appears that with the north winds, the southern barometer was most depressed; while the reverse occurred with the southerly winds.

scholarly journals On irregularities observed in the direction of the compass needles of H. M. S. Isabella and Alexander, in their late voyage of discovery, and caused by the attraction of the iron contained in the ships

1833 ◽  
Vol 2 ◽  
pp. 109-109
Keyword(s):  
Magnetic Meridian ◽  
Magnetic Needle ◽  
Made In

In this paper Captain Sabine shows in what respect the effects of local attraction in the above-mentioned ships were conformable to observations made in previous voyages; and how far the errors found to take place on different courses, and under different dips of the magnetic needle, corresponded with those rules for calculating corrections recommended by Captain Flinders, who found that in every ship a compass would differ very materially from itself on being removed from one place to another, and this was found to be the case in the Isabella and Alexander. As the ships ascended Davis’s Straits, the binnacle compasses, in consequence of their construction, became nearly useless; accordingly, a standard compass was placed in the Isabella exactly amidship between the main and mizen mast, on a stout cross-beam, about nine feet above the deck; and in the Alexander amidship, on a box of sand five or six feet above deck. Captain Sabine next describes the methods by which the points of no error in these compasses were determined, and which were not in either ship coincident with the magnetic meridian.

III.—A Portable Dial in the form of a book, with Figures derived from Raymond Lul

Archaeologia ◽  
1925 ◽  
Vol 74 ◽  
pp. 89-102 ◽  
Author(s):  
O. M. Dalton
Keyword(s):  
British Museum ◽  
Society Of Jesus ◽  
The North ◽  
The Subject ◽  
Lower Cover ◽  
Made In

The dial forming the subject of this paper, acquired by the British Museum in 1923, is of gilt copper, made in the form of a book, along the edges of which are inscribed in capitals the words: Lucerna instrumentalis | intellectus directiva | sive instrumentum sciendi. The dial-plate which is fixed in the interior has a compass and two very short gnomons. It is for use in the latitudes of 42 and 45, and would serve for Rome and one of the large towns in the North Italian plain, perhaps Milan or Venice. It was made at Rome in the year 1593, as shown by the inscription on the dial-plate. On the cover is a shield of arms, barry, and in chief the letters I H S surmounted by a cross, a feature perhaps indicating that the owner was a member of the Society of Jesus; a fuller device, in which the three nails of the Passion are seen below the sacred monogram and cross, occupies the centre of the figure on the outside of the lower cover. The identification of the arms presents difficulties. They might be those of the Caraffa (gules, three bars argent), a member of which family, Vincenzio Caraffa, was general of the Jesuits in 1645.

scholarly journals On the determination of the difference of longitude, by means of the magnetic telegraph. By Elias Loomie, Esq., in a letter to Lieut.-Col. Sabine, R. A., For. Sec. R. S. Communicated by Lieut.-Col. Sabine, R. A., For. Sec. R. S

1851 ◽  
Vol 5 ◽  
pp. 787-789
Keyword(s):  
New York ◽  
Usual Manner ◽  
Series Of Experiments ◽  
The Difference ◽  
The Times ◽  
The Right ◽  
Time Pieces ◽  
Right Ascension ◽  
Source Of Error

The writer first refers to a series of experiments made under the direction of Professor Bache, for the determination of the difference of longitude between New York, Philadelphia and Washington, by means of the magnetic telegraph. By this series of experiments he considers it established that, by means of Morse’s telegraph, two clocks distant from each other 200 miles, can be compared together with the same precision as if they were placed side by side; and that the difference of longitude of two places can be determined with the same precision as the relative error of the clocks. These results were so satisfactory that Professor Bache determined to pro­secute them more extensively, and during the past summer comparisons have been made between New York and Cambridge observatory near Boston. The plan of operation this season was more matured than during the former. The comparisons were all made between a solar chronometer at Cambridge and a sidereal clock at New York. At ten o’clock in the evening, the two observatories having been put in telegraphic communication, when the seconds hand of the solar chronometer came round to 60 s , a signal was given at Cambridge, by pressing the key of the telegraph-register; at the same instant a click was heard at New York, and the time was recorded according to the sidereal clock. At the end of 10 s a second signal was given, which was also recorded at New York; at the end of another 10 s a third signal was given, and so on for sixty seconds. The Cambridge astronomer then commenced beating seconds by striking the key of the telegraph-register in coincidence with the beats of his chronometer. The New York astronomer compared the signals received with the beats of his clock, and waited for a coincidence. When the beats were sensibly synchronous the time was recorded, and the astronomer waited six minutes for another coincidence of beats. The Cambridge astronomer continued beating seconds for fifteen minutes , during which time the New York observer was sure of two coincidences, and might obtain three. When these were concluded, the New York astronomer in the same manner gave signals for one minute at intervals of 10 s , and then beat seconds for fifteen minutes, during which time the Cambridge astronomer obtained four or five coincidences upon his chronometer. This mode of comparison was practised every night, and it is considered that the uncertainty in the comparison of the time-pieces cannot exceed two or three hundredths of a second on any night; and in a series of comparisons the error may be regarded as entirely eliminated. Another mode of comparison which was practised is that of telegraphing star transits. A list of stars which culminate near our zenith at intervals of five or six minutes was prepared, and the observers, both at New York and Cambridge, were furnished with a copy. They then proceeded as follows: Cambridge selected two stars from the list, which we wall call A and B, and struck the key of his register at the instant when the star A passed each of the seven wires of his transit. These signals were heard at New York, and the times recorded. Cambridge then observed the transit of star B in the ordinary manner without telegraphing. New York then observed the transit of star A on his meridian in the usual manner; and struck his key at the instant the star B passed each of the seven wires of his transit, which signals were heard and recorded at Cambridge. The difference of longitude between New York and Cambridge is nearly twelve minutes, affording ample time for all these observations. Thus New York obtained upon his own clock the times of transit of star A over the meridians of Cambridge and New York; and Cambridge obtained upon his chronometer the times of transit of star B over the same meridians. The difference of these times gives the difference of longitude independent of the right ascension of the stars. Both observers then reversed the axis of their transit instruments; Cambridge selected a second pair of stars from the list, and the same series of observations was repeated as with the first pair. The error of collimation was thus eliminated, and by confining the observations to stars within about five degrees of the zenith, the influence of azimuthal error was avoided. The level being read at every reversal, the correction for it was applied by computation. In this manner it is hoped to eliminate every possible source of error, except that which arises from the personal habits of the observers. In order to eliminate this error, a travelling observer worked for a time at Cambridge and compared with the Cambridge astronomer; then came to New York and compared with the New York astronomer; then returned to Cambridge again, and so on as often as was thought necessary. Finally, at the conclusion of the campaign all the observers were to meet at Cambridge and make a general comparison of their modes of observation.

scholarly journals On the results of tide observations, made in June 1834, at the Coast-Guard stations in Great Britain and Ireland

1837 ◽  
Vol 3 ◽  
pp. 329-330
Keyword(s):  
High Water ◽  
Coast Guard ◽  
Maximum Magnitude ◽  
The Moon ◽  
Diurnal Difference ◽  
Exact Determination ◽  
The Subject ◽  
The Times ◽  
Two Sides ◽  
Made In

On a representation made by the author of the advantages which would result from a series of simultaneous observations of the tides, continued for a fortnight, along a great extent of coast, orders were given for carrying this measure into effect at all the stations of the Preventive service on the coasts of England, Scotland, and Ireland, from the 7th to the 22nd of June inclusive. From an examination of the registers of these observations, which were transmitted to the Admiralty, but part of which only have as yet been reduced, the author has been enabled to deduce many important inferences. He finds, in the first place, that the tides in question are not affected by any general irregularity, having its origin in a distant source, but only by such causes as are merely local, and that therefore the tides admit of exact determination, with the aid of local meteorological corrections. The curves expressing the times of high water, with relation to those of the moon’s transit, present a very satisfactory agreement with theory; the ordinates having, for a space corresponding to a fortnight, a minimum and maximum magnitude, though not symmetrical in their curvatures on the two sides of these extreme magnitudes. The amount of flexure is not the same at different places; thus confirming the result already obtained by the comparison of previous observations, and especially those made at Brest; and demonstrating the futility of all attempts to deduce the mass of the moon from the phenomena of the tides, or to correct the tables of the tides by means of the mass of the moon. By the introduction of a local, in addition to the general, semimenstrual inequality, we may succeed in reconciling the discrepancies of the curve which represents this inequality for different places; discrepancies which have hitherto been a source of much perplexity. These differences in the semimenstrual inequality are shown by the author to be consequences of peculiar local circumstances, such as the particular form of the coast, the distance which the tide wave has travelled over, and the meeting of tides proceeding in different directions; and he traces the influence of each of these several causes in producing these differences. A diurnal difference in the height of the tides manifests itself with remarkable constancy along a large portion of the coast under consideration. The tide hour appears to vary rapidly in rounding the main promontories of the coast, and very slowly in passing along the shores of the intervening bays; so that the cotidal lines are brought close together in the former cases, and, in the latter, run along nearly parallel to the shore; circumstances which will also account for comparative differences of level, and of corresponding velocities in the tide stream. The author intends to prosecute the subject when the whole of the returns of these observations shall have undergone reduction.

scholarly journals XI. Researches on the tides.—tenth series. on the laws of low water at the port of plymouth, and on the permanency of mean water

1839 ◽  
Vol 129 ◽  
pp. 151-161 ◽  
Keyword(s):  
High Water ◽  
Level Line ◽  
English Channel ◽  
Know How ◽  
North Shore ◽  
The North ◽  
South Shore ◽  
The Subject ◽  
The Mean ◽  
The Difference

In former communications to the Society, the laws of high water at Plymouth and other places have been the subject of my researches. These being obtained, the laws of low water are a subject of importance and interest on many accounts. The first ground of my pursuing this subject was the desire to ascertain how far the mean water , that is, the height midway between high and low water, is permanent during the changes which high and low water undergo. That it is approximately so at Ply­mouth, had been ascertained both by Mr. Walker and myself, by means of a com­parison of a short series of observations. But it was desirable to know with more exactness what was the real amount of this permanency, when, by using a long series of observations of high and low water, the irregularities arising from accident, and from taking imperfect cycles of inequalities, were eliminated. There was another reason which made this inquiry important at the present time. An operation has been recently carried on by the direction and at the expense of the British Association, with a view of ascertaining what surface ought to be taken as the permanent level of the sea. A Level Line has been carried with great care and accuracy from the north shore of Somerset to the south shore of Devon ; and the po­sition of this line has been fixed, so as to be recognised at any future time, by means of marks at Axmouth, at East Quantockshead, at Stolford, and at Portishead. This line has also been referred to the sea at its extremities ; and the observations show that the height of mean water coincides, at least very nearly, at different places, as well as at the same place at different times. While the difference of levels of low water at Axmouth on the English Channel, and Wick Rocks on the Bristol Channel, is not less than twelve feet; the mean water at those two places coincides in level within a few inches. In order to determine further what accuracy may be attained in this result, we are led to inquire what is the degree of permanency at one place. I may further add, that it cannot but be instructive to know how far the corrections of the height and time of low water, for lunar parallax and declination, agree in form and amount with the same corrections already obtained for high water.

scholarly journals Evaluation of the Kinect controller precision

2021 ◽  
Vol 18 ◽  
pp. 15-21
Author(s):  
Piotr Mieszawski ◽  
Tomasz Szymczyk
Keyword(s):  
Research Study ◽  
Operation Research ◽  
Hand Movement ◽  
Real Life ◽  
The Subject ◽  
The Difference ◽  
Made In

The subject of this work is to evaluate the precision of the Kinect controller operation. Research study was performed and a measuring stand have been prepared. Then an application was created that captures the user's throw gesture and simulates the flight of a virtual ball. Based on this, measurements were made to determine the difference between hand movement and it’s detection by the application, and differences among throw made in real life and in VR. The analysis of these results allowed the accuracy of the controller to be assessed.

scholarly journals Alfred George Hastings White (1859-1945)

1946 ◽  
Vol 4 (1) ◽  
pp. 109-112
Keyword(s):  
Royal Society ◽  
Trinity College ◽  
The North ◽  
The Press ◽  
Walter White ◽  
Scientific Papers ◽  
The Subject ◽  
Regent's Park ◽  
Library Catalogue ◽  
General Secretary

In 1872 the Royal Society occupied quarters in Old Burlington House. The wings of the new building had been completed and the Society awaited the furnishing of the rooms before moving to its present home. At that time Walter White was Assistant Secretary and Librarian; Henry B. Wheatley was Clerk and Henry White had charge of the Catalogue of Scientific Papers . The latter was the father of Alfred George Hastings White, the subject of this notice. Alfred White was born at Albany Street, Regent’s Park, on 9 February 1859. His mother was the daughter of George W. Hastings, who for some years was the Honorary General Secretary of the National Association for the Promotion of Social Science. Henry White, the father, came of an old Reading family. He was educated at Trinity College, Cambridge, where he took his M.D., but he never practised as a doctor. Alfred White was educated at the North London Collegiate School for Boys in Camden Road, where he gained a reputation for a quickness in learning, especially with regard to languages. He left school at the early age of thirteen, in January 1873, to help his father at the Royal Society, joining the staff engaged upon the compilation of the Catalogue of Scientific Papers . In the same year, when the Society moved to its new quarters, he had much to do with arranging and shelving the books in the library. In this and the work on the Catalogue he gained valuable experience in library work which was a great help to him when he came to assist his father in preparing a catalogue of the Society’s library. This work occupied some years; and when Henry White died suddenly in 1880 from a heart attack in the Meeting Room of the Society it was left to Alfred White to complete the Library Catalogue and see it through the press. The first part was published in 1881 and the second in 1883.

Bronze Swords in Northern Europe: a reconsideration of Sprockhoff's Griffzungenschwerter

1953 ◽  
Vol 18 (2) ◽  
pp. 129-147
Author(s):  
J. D. Cowen
Keyword(s):  
Northern Europe ◽  
Central Theme ◽  
The Past ◽  
The North ◽  
Intimate Knowledge ◽  
The Subject ◽  
First Time ◽  
Made In

It is just over twenty years since Professor Ernst Sprockhoff published his classic study of bronze swords in Northern Europe, and a review of the situation as it presents itself today, surveyed from a point well outside the limits of the Nordic area, may not be out of place.The ground covered in this fine work had already in part been traversed by Sophus Müller and Gustav Kossinna; but in the process it had become a field of battle where the bitterest partisan spirit had all too recently been displayed, and might all too easily have been re-aroused. It is not the least part of our debt to Sprockhoff that he refused to treat his material on controversial lines, and confined himself to a presentation so objective that it immediately became possible, for the first time for many years, once more to discuss the subject in a sane and cool manner. Thus, adding much that was new and solely his own, he set down in plain, precise terms the whole of the evidence relating to the history, development, and chronology of the flange-hilted bronze swords of the North.Of this structure the main fabric, without any doubt, stands firm. The central theme, based on a large number of closed finds, and supported by an intimate knowledge of the material, need fear no criticism. Yet some aspects at least of the relations between the Nordic world and other parts of Europe call for re-examination, and the work of the past two decades enables some adjustments to be made. In fairness to Sprockhoff it should be stated quite clearly, at the outset, that the most important of these adjustments have been either made possible, or actually anticipated, by his own work in related fields since 1931.

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