100 Association of American Oeologists and Naturalists. 



Extract of a Letter from Baron W. Sartorius von Waltershausen to 

 George Ticknor, Esq. dated Gottingen, Dec. 18, 1843. 



I send you some of the first proof-impressions of the copperplates 

 intended for my work upon ^tna, upon which, as well as upon the 

 publication of the work, I should like to give you some more minute 

 information. » 



Amidst struggles of all sorts, after seven years of uninterrupted la- 

 bor, in which I have avoided neither exertion nor peril, at the expense 

 of not a small part of my fortune, without support from any Euro- 

 pean government, sustained only by the love of nature and by a strong 

 will, I have fortunately attained my object ; and having set aside and 

 overcome all obstacles, I think myself now able to offer to science a 

 work which in other times could have been brought forward only by 

 royal munificence, as for example the Expedition d'Egypte under Na- 

 poleon. 



Meantime six years are still necessary before the whole work can ap- 

 pear ; in each of which years, from this time forward, one portion will 

 come out. The description of the whole, which explains the six divis- 

 ions, will, I hope, be completed in a few years. The work itself will, I 

 think, form a thick quarto volume, called " ^Etna and its Convulsions," 

 and will contain nearly the following matter : 



General scientific, topographic introduction ; astronomical observa- 

 tions to determine the localities ; base measurement and complete tri- 

 angulation of the volcanoes ; topographical description ; trigonometri- 

 cal and barometrical observations to determine heights ; examination 

 of terrestrial magnetism ; mineralogy ; history of eruptions from the 

 Sicanlans to the present day ; the geology, and the origin, and all the 

 changes of the volcano now to be recognized. The conclusion will 

 consist of general remarks upon the theory of volcanoes, and a com- 

 parison of ^tna with the Ligurian volcanoes, Vesuvius, and the ex- 

 tinct volcanoes of the south of Europe. 



The book of plates, which, as I said, will appear in six numbers, 

 consists of about fifty four large engravings ; a topographical map in 

 fifteen sheets, and a geological map in fifteen. The remaining sheets 

 consist of views, sections, and other drawings appropriate to the expla- 

 nation of the text. 



The fact that the work is of too comprehensive a nature and much 

 too costly for a German public, is sufficient to account for my finding 

 it impossible to procure either publisher or bookseller, and therefore I 

 shall be obliged to meet the expenses of the costly publication with my 

 own means. 



As mutual scientific exchange has always had a great charm, and 

 the object of grave works is, at least in part, to be read by an intelli- 



