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LXVII. Some occasional Observations on the Structure, the Melt- 

 ing, and the Crijstallization of Ice, made in Siberia. By A. 

 Erman, Prof. Univ. Berol. 



To John Tyndall, Esq., F.R.S. 

 Dear Sir, 



YOUR important experiments and observations on the phy- 

 sical properties of ice, of which I have read the report in 

 the Philosophical Magazine, No. 108, remind me of some re- 

 marks on the same subject which occurred to me during my 

 travels in Siberia. It seems that at present these remai'ks may 

 become useful ; for some of them agree perfectly with the results 

 which you have already obtained, and therefore confirm them, 

 and some others, like all phfenomena that are still waiting for 

 an explanation, may be an inducement to new experiments. I 

 think, therefore, that either yourself in the second part of your 

 researches, or other observers who may participate in them, 

 would like to take notice of my observations. If you are of this 

 opinion, I should wish the description of what I have given to 

 become known to English philosophers, by your publishing it in 

 the Philosophical Magazine. I have endeavoured to have these 

 observations quite verbally translated from the German volumes, 

 entitled Reise um die Erde, u. s. w., which I published in the 

 years 1835 to 1849; and I hope you will convince yourself of 

 this agreement by comparing them with the passages quoted from 

 the German work. I may add that my translation of many of 

 the passages in question agrees fully with that of Mr. W. D. 

 Cooley, in his somewhat abridged English edition of part of my 

 book, entitled "Travels in Siberia," &c., by A. Erman: London, 

 1848. The remainder of the annexed remarks, however, will be 

 found in full accordance with the German only, whereas some 

 particulars have been omitted in the English abridgement, per- 

 haps as not being of interest to the public in general. I have 

 nevertheless quoted at each of these passages the pages of the 

 English as well as of the German edition, when the phfenomena 

 in question are either merely alluded to, or fully described. 

 Believe me, dear Sir, to be with sincerest regard. 

 Your obedient Servant, 

 Berlin, 122 Fiiedrichstrasse, A. Erman. 



April 23, 1859. 



Structural divisions of ice observed on Lake Baikul. 



(Reise um die Erde, u. s.w., Histor. Ahtheilung, vol. ii. p. 1/5. 

 Travels in Siberia, &c. vol. ii. p. 284.) 



Fetrruary 2G We reached the coasts of the Baikal at 



Posolskoi about three o'clock in the afternoon, and commenced 



