IV. CALCULATION OF BAROMETRIC HEIGHTS.
I. Formula employed.
II. Corrections eor periodic Changes of the Elements. 1. General considerations. 2. Practical application to
corrections. 3. Materials for the yearly period, a. Variation of the barometric heights in the yearly period.
b. Comparison of the curves, c. Corrections for the months. 4. Materials for the daily period, a. Variation of
the barometric heights in the daily period, b. Comparison of the curves. 5. General table of corrections.
HI. Examples. 1. Amarkantak, in Malva, Central India. 2. Mustak pass, in Balti, Tibet.
I. FORMULAE EMPLOYED.
For the calculation of our barometric heights we use the formulae which have
been extended from Gauss' tables by M. C. Dippe \ But as Dippe's tables are based
on Reaumur, and give the resulting height in toises, we had, for one argument, viz.
the sum of the temperatures of the air (t -f- t'), to reduce the table to Fahrenheit and
centigrade measure, and to alter the argument for the correction with the decrease
of gravity.
In accordance with Bessel's calculations, we have added a special correction for
introducing the mean humidity with its full value. We had, however, to reduce
Bessel's table (which is contained in " Schumacher's Astronomische Nachrichten", 1838,
Xo. 356), to English measures, and to extend it, so as to make it available for extreme
heights. All the tables required either for the barometrical or trigonometrical calcu-
lation of heights are given in full at the end of this part; they also contain the
1 Gauss' tables, a re-calculation of La Place's original formulas, are published in "Schumacher's Jahrbuch for
1836"; Dippe's tables, in the "Astronomische Nachrichten, No. 1056, November, 1856". The co-efficients used in these
tables have been recently confirmed by the theoretical researches of Professor Crelle: Einige Bemerkungen iiber die
Theorie des Hohenmessens; Abhandlungen der Berliner Akademie, 1852.
I. Formula employed.
II. Corrections eor periodic Changes of the Elements. 1. General considerations. 2. Practical application to
corrections. 3. Materials for the yearly period, a. Variation of the barometric heights in the yearly period.
b. Comparison of the curves, c. Corrections for the months. 4. Materials for the daily period, a. Variation of
the barometric heights in the daily period, b. Comparison of the curves. 5. General table of corrections.
HI. Examples. 1. Amarkantak, in Malva, Central India. 2. Mustak pass, in Balti, Tibet.
I. FORMULAE EMPLOYED.
For the calculation of our barometric heights we use the formulae which have
been extended from Gauss' tables by M. C. Dippe \ But as Dippe's tables are based
on Reaumur, and give the resulting height in toises, we had, for one argument, viz.
the sum of the temperatures of the air (t -f- t'), to reduce the table to Fahrenheit and
centigrade measure, and to alter the argument for the correction with the decrease
of gravity.
In accordance with Bessel's calculations, we have added a special correction for
introducing the mean humidity with its full value. We had, however, to reduce
Bessel's table (which is contained in " Schumacher's Astronomische Nachrichten", 1838,
Xo. 356), to English measures, and to extend it, so as to make it available for extreme
heights. All the tables required either for the barometrical or trigonometrical calcu-
lation of heights are given in full at the end of this part; they also contain the
1 Gauss' tables, a re-calculation of La Place's original formulas, are published in "Schumacher's Jahrbuch for
1836"; Dippe's tables, in the "Astronomische Nachrichten, No. 1056, November, 1856". The co-efficients used in these
tables have been recently confirmed by the theoretical researches of Professor Crelle: Einige Bemerkungen iiber die
Theorie des Hohenmessens; Abhandlungen der Berliner Akademie, 1852.