scholarly journals IX. On the use of the barometric thermometer for the determination relative heights

1846 ◽  
Vol 136 ◽  
pp. 121-132
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure ◽  
Boiling Point ◽  
Royal Society ◽  
Barometric Pressure ◽  
Boiling Water ◽  
The Alps ◽  
The Law

Although the observation of the temperature of boiling water has been for some time, but not extensively, employed for the determination of relative heights, yet the only means which experiment has confirmed of reducing it to a measure of the atmospheric pressure as usually estimated by the height of an equiponderate column of mercury has, till very recently, been overlooked; and it may perhaps be owing to this circumstance that the instrument for making the requisite observations remains to have fully developed in it the advantages it undoubtedly possesses, in portability and strength of construction, over the fragile and easily deranged barometer. My attention having been called to this subject by a remark made by Professor Forbes in his interesting work on the Alps, to the effect that he had found the temperature of boiling water to decrease uniformly with the increase in height of the place of observation, and at the rate of one degree of Fahrenheit for every 550 feet of vertical ascent, I considered that it would be highly satisfactory to verify this result during an excursion over the Alps of Savoy and Piedmont which I then had in contemplation, and in the course of which I proposed to visit some localities at very considerable elevations above the sea level: and I was induced also to seek for some foundation for this very simple law. In prosecuting the latter inquiry, I soon found that, by assuming the truth of De Luc’s formula for the determination of the boiling-point from the barometric pressure, at all accessible heights, a corroboration of the law in question is at once arrived at. I have since found, by reference to a paper in Vol. xv. of the Transactions of the Royal Society of Edinburgh, that Professor Forbes had himself verified his original conjecture in the same manner.

scholarly journals 3. On the Determination of Heights by the Temperature of Boiling Water

1845 ◽  
Vol 1 ◽  
pp. 412-414
Author(s):  
Forbes
Keyword(s):  
Boiling Point ◽  
Barometric Pressure ◽  
Boiling Water ◽  
The Alps ◽  
Made In

The investigations in this paper were made in order to reduce certain observations on the boiling point of water, made by the author in the Alps, in 1842.He considered that it has been too generally assumed that the boiling point corresponds to a barometric pressure which expresses the elasticity of steam taken from the usual tables. He, therefore, attempted to deduce the connection of these data by a direct comparison of cases, in which both the barometer and boiling point were noticed by himself. He finds this result, that the pressures increase rigorously in a geometrical ratio, whilst the temperature of the boiling point rises uniformly.

2. Note on the Determination of Heights, chiefly in the Interior of Continents, from Observations of Atmospheric Pressure

1869 ◽  
Vol 6 ◽  
pp. 465-472
Author(s):  
Alexander Buchan
Keyword(s):  
Sea Level ◽  
Atmospheric Pressure ◽  
Boiling Point ◽  
Great Distance ◽  
Close Approximation ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Meteorological Observations

The weight or pressure of the atmosphere is ascertained by the mercurial barometer, the aneroid, or from the temperature of the boiling point of water. The height of a hill is measured barometrically, from observations made simultaneously at its base and top, and the application of certain well-known formulæ. The height of a place at no great distance from another place whose height is known, and at which observations are made about the same time, may similarly be ascertained with a close approximation to the truth.But, with regard to places far from any place of known elevation, or from any place at which meteorological observations are made, it is plain that the height can only be computed by assuming a certain pressure as the sea-level pressure at that place.

scholarly journals On the use of the barometric thermometer for the determina­tion of relative heights

1851 ◽  
Vol 5 ◽  
pp. 597-599
Keyword(s):  
Boiling Point ◽  
Theoretical Foundation ◽  
Barometric Pressure ◽  
Boiling Temperature ◽  
Comparison Of Results ◽  
Boiling Points ◽  
The Alps ◽  
The Mean ◽  
The Difference

The objects of this communication, as stated by the author, are, first, to show the theoretical foundation of the very simple law pointed out by Professor Forbes, according to which the difference of the boiling temperature of water at two stations is connected with their difference of level ; and next, to test the accuracy of this law by a comparison of results deduced from his own observations on the boiling-point of water at different stations among the Alps of Savoy, Piedmont and Switzerland, with the heights of the same stations as determined by other observers and by different means ; and thus to arrive at a just conclusion with respect to the value of the barometric thermometer as an instrument for determining differences of level. Combining DeLuc’s formula reduced to English units, b = 99 log 10 β - 60.804, .899 where b is the variable boiling-point on Fahrenheit’s scale and β the corresponding barometric pressure, with the formula of Laplace for the determination of the difference in level of two stations from barometric observations, he obtains the formula H = 547.99 ( b - b' ) { 1 + ( t - 32°) .00222 } , where b and b' are the boiling-points on Fahrenheit’s scale at-the two stations, t the mean temperature of the air at the stations, and H their difference of level in English feet.

scholarly journals XVIII.—On Steam and Brines

1900 ◽  
Vol 39 (3) ◽  
pp. 529-573
Author(s):  
J. Y. Buchanan
Keyword(s):  
Atmospheric Pressure ◽  
Barometric Pressure ◽  
Boiling Water ◽  
Common Salt ◽  
Coarse Powder ◽  
Abundant Supply

The immediate purpose of the present research was the investigation of the temperature at different pressures of boiling mixtures of steam and salts, analogous to the well-known freezing mixtures of ice and salt.When steam is blown through common salt in coarse powder, it condenses to water, which dissolves some of the salt, and the resulting brine is kept boiling by the arrival of more steam. The temperature of this boiling mixture is quite constant so long as there is an abundant supply both of steam and of salt, and as the atmospheric pressure does not change, it is about 8·5° C. above the temperature of boiling water when the barometric pressure is the normal of 760 mm. When the barometric pressure is 560 mm. this excess has fallen to 8·0° C. Most other salts behave in a similar way.

scholarly journals II. On the atmospheric lines of the solar spectrum, illustrated by a map drawn on the same scale as that adopted by Kirchhoff

1875 ◽  
Vol 23 (156-163) ◽  
pp. 201-202
Keyword(s):  
Sea Level ◽  
Royal Society ◽  
Solar Spectrum ◽  
The Sun ◽  
Atmospheric Absorption ◽  
Spectroscopic Observations ◽  
Clear Atmosphere

The spectroscopic observations described in this paper were made with instruments belonging to the Royal Society, and in accordance with certain suggestions which had been made to the author by a committee appointed in consequence of a letter of his to Sir Edward Sabine, President, dated 13th February, 1866. In view of his residence at a considerable height above the sea-level, and of the exceedingly clear atmosphere prevailing at some periods of the year, it was suggested that the locality was peculiarly favourable for a determination of the lines of the solar spectrum due to atmospheric absorption, and that, for this purpose, the solar spectrum when the sun was high should be compared with the spectrum at sunset, and any additional lines which might appear in the latter case should be noted with reference to Kirchhoff’s map. Accordingly the author set to work with the spectroscope first supplied to him, and in the autumns of 1868 and 1869 mapped the differences in question from the extreme red to D. These results appeared in the 'Proceedings of the Royal Society' for June 16,1870, and the map of the spectra, sun high and sun low, of the region in question forms plate 1 of the 19th volume.

scholarly journals On the mean directions and distribution of the lines of equal barometric pressure, and their relations to the mean direction and force of the wind over the British Isles, &c

1877 ◽  
Vol 25 (171-178) ◽  
pp. 515-539
Keyword(s):  
Sea Level ◽  
Common Law ◽  
Barometric Pressure ◽  
Internal Diameter ◽  
Mean Sea Level ◽  
Mean Values ◽  
Exact Determination ◽  
The Mean ◽  
Atmospheric Variations

In considering atmospheric variations, it is always desirable to know, if possible, the mean values about which the others fluctuate: this appears to be especially the case with reference to the direction of the lines of mean barometric pressure and of the atmospheric currents. If any common law exist connecting the statical and dynamical pressure of the air, this will probably show itself with some precision by an investigation in which, all the cases (the observations of every day) being included, deviations from the law may be expected to neutralize each other, and the final results give absolute measures directly comparable with each other. For any exact determination of the lines of equal barometric pressure it is essential to possess observations from stations whose heights above the mean sea-level are accurately known, and made with good instruments which have been compared directly or indirectly with each other. These conditions are well satisfied by the observations made at the Greenwich, Dublin, and Makerstoun Observatories in the eight years 1842 to 1849 (both inclusive). The barometers were all by the same maker, each having a tube of nearly 0·6 inch internal diameter; they were all compared directly or indirectly with the Royal Society’s standard; and the heights of the cisterns were determined by levelling from the sea in each case. Under such circumstances the directions and intervals of the isobaric lines may be found with much more precision than from observations made at any number of stations where these conditions are not fulfilled.

scholarly journals XIV.—Further Experiments and Remarks on the Measurement of Heights by the Boiling Point of Water

1857 ◽  
Vol 21 (2) ◽  
pp. 235-243 ◽  
Author(s):  
James D. Forbes
Keyword(s):  
Boiling Point ◽  
Royal Society ◽  
The Alps ◽  
New Formula

In 1843 I presented a paper to the Royal Society of Edinburgh, giving an account of experiments made on the boiling point of water in the Alps, under various barometric pressures. My object was twofold: first, to describe an apparatus which I considered more practically available than those previously in use; and, secondly, to give a simple, and, as I believed, new formula for computing heights from such observations.With reference to the second point, I became aware, some time after the publication of my paper, that Sir John Leslie had proposed to compute heights by the thermometer, assuming the change of the boiling point to be exactly in proportion to the height ascended. While cheerfully conceding to Sir John Leslie priority on this point, I submit that he did not bring forward experiments to justify its practical adoption.

scholarly journals On the determination of the chief correlations between collaterals in the case of a simple Mendelian population mating at random

1910 ◽  
Vol 83 (561) ◽  
pp. 37-55 ◽  
Keyword(s):  
Royal Society ◽  
Partial Correlation ◽  
Random Mating ◽  
Fundamental Principle ◽  
Mendelian Population ◽  
Geometrical Progression ◽  
The Law ◽  
Successive Generations

(1) In a paper communicated to the Royal Society in April, 1909, Prof. Pearson obtained the gametic correlations between the offspring and the ancestry in each grade in a simple Mendelian population mating at random. By a “simple Mendelian population” for a given character, he understood one which started with any definite ratio of dominant individuals (AA) to recedents ( aa ). These mating at random give rise to a population which may be written in the form p 2 (AA) + 2 pq (A a ) + q 2 ( aa ), and of which, without selection, the proportions of dominants, recedents, and hybrids are known to remain constant, with continued random mating, during successive generations. Prof. Pearson found that, both in the case of gametic and somatic characters, the ancestral correlations diminished in a geometrical progression, and thus obeyed the fundamental principle of the Law of Ancestral Heredity, as deduced from observations on man and other living forms. (2) It is difficult to believe that the characters dealt with in the case of Mendelian investigations on animals can be largely affected by environment, but it is easy to allow for this influence by the method of partial correlation. If, in an investigation on any given character, the subscript 1 denote offspring, 2 the ancestor in any generation, 3 the offspring’s environment, and 4 the ancestor’s environment, then the correlation between 1 and 2 for constant 3 and 4 is given by 34 ρ 12 = r 12 (1 - r 34 2 ) - r 13 r 23 - r 14 r 24 + r 34 ( r 14 r 23 + r 13 r 24 )/{1 - r 23 2 - r 34 2 - r 24 2 + 2 r 23 r 34 r 24 } ½ {1 - r 13 2 - r 14 2 - r 34 2 + 2 r 13 r 34 r 14 } ½ .

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