Tables of physical and chemical constants and some mathematical functions / by G.W.C. Kaye and T.H. Laby.

  • Kaye, G. W. C. (George William Clarkson), 1880-1941.
Date:
[1941]
Catalogue details

Licence: Public Domain Mark

Credit: Tables of physical and chemical constants and some mathematical functions / by G.W.C. Kaye and T.H. Laby. Source: Wellcome Collection.

    39/200 (page 27)
    BAROMETRY REDUCTION OF BAROMETER READINGS TO 0°C. Corrected height HQ = H^i — where H and t are the observed height and temperature of the barometer, £ = * *0001818 (Regnault), the coefficient of cubical expansion of mercury; a = *0000085, the coefficient of linear expansion of glass, or *0000184 for brass. Hydrogen temperature scale. (After Broch, Inter. Bur. Weights and Measures.) (In accurate barometry, the height of the mercury column is corrected to o° C. (320 F.). Inch scales are corrected to 62° F., and mm. scales, as in the table below, to o° C. Correction in mms. to be subtracted. GLASS SCALE. BRASS SCALE. Temp. (/). Uncorrected height in mms. TJncorrected height in mms. 700 720 740 760 780 700 720 740 760 780 mm. mm. 2° C. •24 •25 •26 *2 6 •27 •23 •24 *24 '25 '25 4 •48 *49 •51 '53 '54 •46 '47 •48 '50 '5i 6 73 75 77 79 •81 •69 71 •72 *74 •76 8 •97 '99 1*02 1*05 1*08 '91 '94 '97 '99 1*02 10 1*21 1*25 1*28 I’3I i'35 1*14 1*17 1*21 1*24 1*27 12 i-45 1*49 i*53 1*58 1*62 i'37 1*41 I'45 1'49 **53 14 1*69 1*74 1*79 1*84 1*89 i*6o 1*64 1*69 i'73 1*78 16 1*94 r99 2*05 210 2*16 1*82 i*88 I'93 1’98 2*03 18 2*18 2*24 2*30 2*36 2‘43 2*05 2*11 2*17 2*23 2*29 20 2*42 2*49 2*56 2-62 2*69 2*28 2*34 2*41 2*47 2'54 22 2*66 273 2*81 2*89 2*96 2*51 2*58 2*65 2*72 2*79 24 2*90 2*98 3*06 3*i5 3'23 273 2'8i 2-89 2’97 3’°5 26 3'*4 323 3‘32 3'4i 3'5° 2*96 3'°4 3'i3 3*21 3’3° 28 3'38 3*47 3*57 3*67 377 3'*9 3*28 3‘37 3’46 3*55 30 3*62 372 3'83 3'93 4'°3 3'4i 3*5i 3-61 371 3'8o 32 3-86 3‘97 4*08 4*19 4'3° 3*64 374 3-85 3*95 4’°5 34 4*10 4*21 4*33 4'45 4‘57 3*87 3'98 4*09 4*20 4'3* REDUCTION OF BAROMETER READINGS TO LAT. 45° AND SEA-LEVEL It is a convention to take ug” at lat. 450 and sea-level as the standard value for “gravity.” The corrections below result from the variation of “g” with latitude and height above sea-level (see p. 18). The barometer correction for latitude = ^~^(C), has to be subtracted from the temperature—corrected barometer reading H0 for latitudes between o° and 450 ; and added for latitudes from 450 to 90° Latitude C 0° 90° mm. 1'97 5° 85° 1*94 10° 80° 1*85 15° 75° 1*70 20° 70° i*5i 25° 65° 1*27 30° 60° •98 35° 55° •67 40° 50° *34* 45° 45° *00 The correction of the barometer due to diminution of gravity with increasing height above sea-level amounts to about *24 mm. of mercury per 1000 metres above sea-level. The correction has to be subtracted from the observed reading. * London, *45.