In the south-east of Servia, on the western slope of Mount Rtagn, is a pit 20 feet in diameter, and 40 or 50 feet deep, the bottom of which is reached by a succession of trunks of trees with the branches lopped off, a sort of ladder called _stouba_ by the natives.[172] The peasants assert that the snow and ice disappear from this pit in September, and do not reappear before June. The Swiss peasants have never yet got so far as to say that the _snow_ in their pits disappears in winter and returns in summer. Boué[173] found the temperature of the bottom of the pit to be 28°.4 F., while that of the air outside was 76° F. The same writer[174] mentions a source in a mill-stone quarry in Bosnia which is frozen till the end of June. FOOTNOTES: [Footnote 122: Several of these caves are referred to by Reich, _Beobachtungen über die Temperatur des Gesteins in verschiedenen Tiefen in den Gruben des Sächsischen Erzgebirges;_ Freiberg, 1834.] [Footnote 123: _Naturwunder des Oesterr. Kaiserthums_, iii. 40.] [Footnote 124: _Mittheil. des Oesterr. Alpen-Vereins_, ii. 441. I am indebted to G.C. Churchill, Esq., one of the authors of the well-known book on the Dolomite Mountains, for my knowledge of the existence of this cave, and of the Kolowrathöhle.] [Footnote 125: _Beschreibung merkwürdiger Höhlen_, ii. 283.] [Footnote 126: _Geognostísche Reschreibung des bayerischen Alpengebirges_; Gotha, 1861.] [Footnote 127: These constitute the upper bone bed and Dachstein limestone beds of the uppermost part of the Trias formation.] [Footnote 128: _Hereynia Curiosa_, cap. v. The same account is given in Behren's _Natural History of the Harz Forest_, of which an English translation was published in 1730.] [Footnote 129: See also Muncke, _Handbuch der Naturlehre_, iii. 277; Heidelberg, 1830.] [Footnote 130: See page 58. The more modern spelling is _frais-puits_.] [Footnote 131: liv. 292.] [Footnote 132: Described by Schaller, _Leitmeritzer Kreis_, p. 271, and by Sommer, in the same publication, p. 331. I have not been able to procure this book.] [Footnote 133: _Böhmens Topogr._, i. 339. This reference is given by Professor Pleischl.] [Footnote 134: _Annalen_, lxxxi. 579.] [Footnote 135: I was told, in 1864, by a chamois-hunter of Les Plans, a valley two hours above Bex, that some years before he was cutting a wood-road through the forest early in September, when, at a depth of 6 inches below the surface, he found the ground frozen hard. We visited the place together, but could find no ice. The whole ground was composed of a mass of loose round stones, with a covering of earth and moss, and the air in the interstices was peculiarly cold and dry.] [Footnote 136: _Beobachtungen_, &c. (see note on p. 258), 181.] [Footnote 137: Reich found the temperature of the ice to be 31·982° F., that of the air in the immediate vicinity 34·025°, and the rock, at a little distance, 32·765°.] [Footnote 138: iii. 150.]