scholarly journals III. Account of the observations and computations made for the purpose of ascertaining the amount of the deflection of the plumb-line at Arthur’s seat, and the mean specific gravity of the Earth; with an account of the observed and computed amount of the local attraction at Arthur’s seat and at the Royal Observatory at Edinburgh

1857 ◽  
Vol 8 ◽  
pp. 45-47
Keyword(s):  
Plumb Line ◽  
Great Pleasure ◽  
Ordnance Survey ◽  
The Public ◽  
The United Kingdom ◽  
The Earth ◽  
Royal Observatory ◽  
The Press ◽  
The Mean

Col. James begins by observing, that as the Royal Society has, from the very commencement of the Ordnance Survey of the United Kingdom, taken a deep interest in its progress, he has great pleasure in announcing to the Society that all the computations connected with the Primary Triangulation, the measurement of the Arcs of Meridians and the determination of the figure and dimensions of the earth are now completed, and that the account of all the operations and calculations which have been undertaken and executed is now in the press, and will shortly be in the hands of the public. In the progress of these operations it has been found, on determining the most probable spheroid from all the astronomical and geodetic amplitudes in Great Britain, that the plumb-line is considerably deflected at several of the principal Trigonometrical Stations, and at almost every station the cause of the deflection is apparent in the configuration of the surrounding country.

scholarly journals XXVIII. On the deflection of the plumb-line at Arthur's seat, and the mean specific gravity of the earth

1856 ◽  
Vol 146 ◽  
pp. 591-606 ◽  
Keyword(s):  
United Kingdom ◽  
Specific Gravity ◽  
Royal Society ◽  
Great Pleasure ◽  
Ordnance Survey ◽  
The Public ◽  
The United Kingdom ◽  
The Earth ◽  
The Press ◽  
The Mean

The Royal Society has, from the very commencement of the Ordnance Survey of the United Kingdom, taken a deep interest in its progress. I have therefore great pleasure in announcing to the Society the completion of all the computations connected with the Primary Triangulation, the measurement of the Arcs of Meridians, and the figure and dimensions of the Earth. The account of all the operations and calculations which have been undertaken and executed is now in the press, and will shortly be in the hands of the public.

Bouguer Redeemed: The Successful 1737-1740 Gravity Experiments on Pichincha and Chimborazo

2010 ◽  
Vol 29 (1) ◽  
pp. 1-25 ◽  
Author(s):  
John Smallwood
Keyword(s):  
Plumb Line ◽  
Near Surface ◽  
The Earth ◽  
Digital Elevation ◽  
The Mean ◽  
Good Determination ◽  
Elevation Model ◽  
Academy Of Sciences ◽  
Regional Gravity

During the 1735-1745 French Academy of Sciences expedition to Peru, Pierre Bouguer conducted two experiments confirming Newtonian gravitational attraction and estimating the mean density of the Earth. One set of experiments determined the variation in gravity with altitude using a pendulum at sea level, Quito (2,860 m) and the summit of Pichincha (4,784 m). Qualitatively correct, Bouguer reported a smaller decrease in gravity than that predicted from altitude increase alone, but he calculated that the mean density of the Earth was nearly five times that of the near-surface rocks, an overestimate by a factor of at least two. The better reported experiment was an attempt to detect the deflection of the vertical near the mountain Chimborazo. There was a large difference between Bouguer's predicted plumb-line deflection, 103", and that which he and La Condamine measured, just 7". I have investigated both experiments using a digital elevation model to compute the vertical and horizontal components of the gravity field caused by topography, and include the regional gravity signature of the Andean crustal root. The modelling indicates not only that Bouguer's pendulum measurements were extremely accurate, but also that his observations allow a good determination of the significant isostatic effect. In contrast, on Chimborazo, contrary to recent suggestions, isostatic effects are negligible, and Bouguer's deflection was, within error, in line with the modelled plumb-line deflection from topography. Both Bouguer's pendulum and plumb-line measurements were reliable and therefore he should now be redeemed from any inference of failure.

scholarly journals XIV. On a determination of the mean density of the Earth and the gravitation constant by means of the common balance

1891 ◽  
Vol 182 ◽  
pp. 565-656 ◽  
Keyword(s):  
Royal Society ◽  
Torsion Balance ◽  
Chemical Balance ◽  
The Earth ◽  
The Common ◽  
The Mean ◽  
Common Balance

In a paper printed in the Proceedings of the Royal Society,' No. 190, 1878 (vol. 28, pp. 2-35), I gave an account of some experiments undertaken in order to test the possibility of using the Common Balance in place of the Torsion Balance in the Cavendish Experiment. The success obtained seemed to justify the intention expressed in that paper to continue the work, using a large bullion balance, instead of the chemical balance with which the preliminary experiments were made. As I have had the honour to obtain grants from the Royal Society for the construction of the necessary apparatus, I have been able to carry out the experiment on the larger scale which appeared likely to render the method more satisfactory, and this paper contains an account of the results obtained.

scholarly journals IV. On the effect of local attraction upon the plumb-line at stations on the English Arc of the Meridian, between Dunnose and Burleigh Moor; and a method computing its amount

1856 ◽  
Vol 146 ◽  
pp. 31-52 ◽  
Keyword(s):  
Plumb Line ◽  
The Earth

1. In a former communication I endeavoured to point out a method for calculating the deflection of the plumb-line at stations on the Indian arc, caused by the attraction of the Himalayas and the vast regions beyond, with a view to the correction of the astronomical amplitudes of the measured subdivisions of the arc, before they are applied to the determination of the ellipticity of the earth. The same subject is taken up in the present paper, but in reference to one of the English arcs, that between Dunnose and Burleigh Moor; and a different method of calculating the attraction is given.

scholarly journals An experiment with the balance to find if change of temperature has any effect upon weight

1905 ◽  
Vol 76 (512) ◽  
pp. 445-457 ◽  
Keyword(s):  
Low Temperatures ◽  
Secondary Effect ◽  
Boiling Liquid ◽  
The Earth ◽  
Exact Determination ◽  
The Mean ◽  
Very High ◽  
The Ideal

In all the experiments hitherto made to determine the gravitative attraction between two masses, the temperature has not varied more than a few degrees, and there are no results which would enable us to detect with certainty any dependence of attraction upon temperature even if such dependence exists. It is true, as Professor Hicks has pointed out, that Baily’s results for the Mean Density of the Earth, if arranged in the order of the temperature of the apparatus when they were obtained, show a fall in value as the temperature rises. But this is almost certainly some secondary effect, due to errors in the measurements of the apparatus, or to the seasons at which different attracted masses were used. The ideal experiment to find if temperature has an effect on gravitation would consist in one determination of the gravitative attraction between two masses at, say 15°C., and another determination at, say, the temperature of boiling liquid air. But the difficulties of exact determination at ordinary temperatures are not yet overcome, and at any very high or very low temperatures, they would be so much increased that the research seems at present hopeless.

Studying, Working, and Living in Another EU Country

2000 ◽  
Vol 5 (3) ◽  
pp. 216-227 ◽  
Author(s):  
Etienne Mullet ◽  
Véronique Dej ◽  
Isabelle Lemaire ◽  
Philippe Raïff ◽  
Jolyon Barthorpe
Keyword(s):  
Factor Analysis ◽  
United Kingdom ◽  
Family Influence ◽  
Eu Countries ◽  
The United Kingdom ◽  
Confirmatory Factor ◽  
The Family ◽  
The Mean ◽  
Very High

This study assessed the willingness of French youth to go and study or work for some time in another EU country. We examined three types of questions: (a) What is the overall level of willingness to go in another EU country? Does age, gender or socioeconomic status (SES) of the family influence this overall level? Which country do French youth prefer to go to? (b) Is a four-factor Push-Anti-Push-Pull-Anti-Pull model able to account for data regarding attitudes toward other countries and attitudes toward France? (c) Is this model able to predict willingness to go and study or work in another EU country, both generally and for individual countries? The overall level of willingness to go to other EU countries was not very high. Except for the United Kingdom the mean response was always located closer to the “No” pole than to the “Quite possible” pole. Gender, age, and educational level of the father did not play a role. Participants clearly preferred the United Kingdom and Spain to Germany or The Netherlands. Exploratory factor analysis showed a clearly interpretable Push-Anti-Push-Pull-Anti-Pull solution, and confirmatory factor analysis showed that this structure fits the attitudes data very well according to the usual indices. This general model, however, did not explain much of the “intent-to-go” variance. In addition, specific Pull attractiveness considerations (liking and knowing the country) played, beyond the general Push-Pull model, a notable role in the determination of willingness to go and study or work in each of the 14 EU countries.

An Early Geophysical Estimate of the Mean Density of the Earth: Schehallien, 1774

1984 ◽  
Vol 3 (2) ◽  
pp. 149-152 ◽  
Author(s):  
G. Ranalli
Keyword(s):  
Terrain Correction ◽  
Detailed Account ◽  
Plumb Line ◽  
Scottish Highlands ◽  
The Earth ◽  
The Mean ◽  
Nevil Maskelyne ◽  
The Hill

The Schehallien experiment, begun in 1774, represented one of the earliest attempts, after Bouguer's work in the Viceroyalty of Peru, to determine the mean density of the earth from the observed effects of topography on the direction of the plumb-line. The site chosen was a hill in Perthshire in the Scottish Highlands, and the work involved Nevil Maskelyne, the Astronomer Royal, who carried out the survey; Charles Hutton, the mathematician, who in 1778 published a method to compute the effect of a mass of known shape of the plumb-line; and John Playfair, who in 1811 published a detailed account of the lithology of the hill. Hutton's and Playfair's work foreshadowed in many respects modern aspects of gravity surveys such as terrain correction and density sampling.

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