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Page 37 - X 60158.6 for every hundredth of an inch, from 12 to 31 inches in the barometer, together with the value of the additional thousandths, in a separate column. These values have been diminished by a constant, which does not alter the difference required. Table II. gives the correction 2.343 feet X (т — r1) for the difference of the temperatures of the barometers at the two stations, or т — t'.
Page 112 - This last quantity was declared in 1799 to be the length of the legal metre, and frai et définitif, and is the length of Lenoir's platina standard. Later and more extensive measurements in various parts of the globe, however, seem to indicate that this quantity is somewhat too small. The latest and most exact results we now possess, combined and computed by Bessel, would make the quarter of the meridian 10,000,856 metres, and the metre = 443.29979 Paris lines ; Schmidt's computation would make it...
Page 38 - D' and the height of the barometer at the lower station, take the corrections for the decrease of gravity on a vertical, and add them to the approximate difference of level. The sum thus found is the true difference of level between the two stations, or Z; by adding the elevation of the lower station above the level of the sea, when known. we obtain the altitude of the upper station. The...
Page 98 - When water is heated, the elastic force of the vapor produced from it gradually increases until it becomes equal to the incumbent weight of the atmosphere. Then, the pressure of the atmosphere being overcome, the steam escapes rapidly in large bubbles, and the water boils.
Page 12 - Bessel's tables, because Plantamour substituted for Laplace's barometrical coefficient that derived from the probably more accurate determination of the relative weight of the air and mercury by Regnault, viz. 18404.8 metres. E. Ritter's tables, computed from his own formula, give perhaps, in extreme cases, better results ; but as, in ordinary circumstances, the altitudes obtained do not much differ from those furnished by the less complicated tables of Plantamour, they were not reprinted here.
Page 85 - From the foregoing statements it may be safely inferred that " the mean height of the barometer at the level of the sea being the same in every part of the globe...
Page 51 - T', the temperature of the barometer, ' t', the temperature of the air. Represent by s the height of the lower station above the level of the sea, by L the latitude of the place, and by h the observed height h' reduced to the temperature T.
Page 37 - D1 -^^s^r to be applied to the approximate altitude for the decrease of gravity on a vertical acting on the density of the mercurial column. It is always additive.
Page 52 - Ла^а^'» which is always to be added to the approximate height A, and which is due to the diminution of gravity on the vertical. Part V. furnishes for the approximate difference of level A the small correction AX |(цц3|5 corresponding to several values of the height s of the lower station.
Page 74 - ... however, be observed, that this table is only calculated for barometers whose scales are engraven upon a rod or plate of brass reaching from the level of the mercury to the vernier. In many barometers the scale is engraved upon a short plate of brass fixed upon the wooden frame of the instrument, and the compound expansion of the two substances can only be guessed at, but must be obviously less than if the whole length had been of brass. As a near approximation for such imperfect instruments,...