FREEZING CAVERN AT ILLETZKAYA-ZASTCHITA. 
189 
“ I should observe, that in the recorded observations of the Ekaterinenburg ob- 
servatory, the temperatures are observed two-hourly, from eight a.m. to ten p.m., 
and not at night. The mean monthly temperatures are thence concluded by a 
formula which I am not very well satisfied with ; but the error, if any, so intro- 
duced must be far too trifling to affect this argument. The works whence the 
above data are obtained are ‘ Observations Mcteorologiques et Magnetiques faites 
dans l’lnterieur de l’Empire de Russie,’ and ‘ Annuaire Magnetique et Meteorolo- 
gique du Corps des Ingenieurs des Mines de Russie,’ works which we owe to the 
munificence of the Russian government, and which it is satisfactory to find thus 
early affording proofs of utility to science in explaining what certainly might be 
regarded as a somewhat puzzling pbsenomenon, as it is one highly worthy of being 
further studied and being made the subject of exact thermometric researches on the 
spot, and wherever else anything similar occurs.” 
“ P.S. Thermometric observations in the steppes, of the mean monthly tempera- 
ture of the soil at different depths from one to 100 feet (at Forbes’s intervals), would 
be most interesting. At Ekaterinenburg the mean temperature of the air being 
36 0, 6 Fahr., no permanently frozen soil would probably be reached, but a very little 
more to the northward that phenomenon must occur. 
“ The ‘ thinning out ’ of the frozen stratum would be most interesting to trace, 
but in thinning out by decrease of latitude it might possibly at the same time 
‘ dip’ beyond reach, all above i't being occupied by soil subject to the law of pe- 
riodic frost and thaw, and giving room under favourable circumstances to ice- 
caverns, pits, or galleries. What determines the distinct definition of the hot 
and cold alternating layers is the exceedingly peculiar form of the curve of the 
monthly temperatures as given in the tables above referred to.” 
In thanking Sir John Herschel for his efforts (amid his numerous important re- 
searches) to explain the wonders of our cave of Illetzkaya, we think it right to 
state, that even his explanation has to contend with some strong local objections. 
The little hillock of gypsum, for example, not exceeding 150 feet in height, and 
of an irregular conical form, is the seat of other rents and openings, no one of 
which, as we were informed, contains snow or ice. Why therefore does our cave 
present this exceptional phenomenon ? How indeed are we to imagine that a six 
months’ wave of cold shall affect a cavern in a small mount, and not the subsoil 
of the surrounding country 1 ? Again, if there be no connection between the hot 
' Although they have no direct application to our case of Illetzkaya, we may state that the phamo-. 
2 C 
