[28] Annales chim. et phys., 1892 [6], 26. 425.
[29] The vapour pressure of water at 0° has recently been very accurately determined by Thiesen and Scheel (loc. cit.), and found to be 4.579 ± 0.001 mm. of mercury (at 0°), or equal to 0.006025 atm.
[30] Juhlin, Bihang Svenska Akad. Handl., 1891, 17. I. 58. See also Ramsay and Young, loc. cit.
[31] Trans. Roy. Soc. Edin., 1849, 16. 575.
[32] Proc. Roy. Soc. Edin., 1850, 2, 267.
[33] Annalen der Physik, 1899 [3], 68. 564; 1900 [4], 2. 1, 424. See also Dewar, Proc. Roy. Soc., 1880, 30. 533.
[34] The pressure of 1 atmosphere is equal to 1.033 kilogm. per sq. cm.; or the pressure of 1 kilogm. per sq. cm. is equal to 0.968 atm.
[35] Tammann, loc. cit., 1900, 2. 1, 424; cf. Goossens, Arch. néerland, 1886, 20. 449.
[36] J. Thomson, Proc. Roy. Soc., 1874, 22. 28.
[37] A field is "enclosed" by two curves when these cut at an angle less than two right angles. It may be useful to remember that an invariant system is represented by a point, a univariant system by a line, and a bivariant system by an area.