8 
PREFACE. 
authors, and if I have not quoted his researches 
more often, it is because I have been anxious to 
give the latest authorities. In 1858 he suggested 
that the Dufour map should be taken as the basis 
of a geological survey on a larger scale. To this the 
Swiss Government assented; they voted the modest 
sum of £ 120, since increased to £400 a year, and 
appointed a Commission, consisting of Messrs. B. 
Studer, P. Mirian, A. Escher von der Linth, A. Favre, 
and E. Desor. Under their supervision the present 
geological map, in twenty-five sheets, has gradually 
appeared: the last being published in 1888, on the 
very day of Studer’s death. 
In addition to the geological maps themselves, 
the Commission have published a splendid series of 
descriptive volumes, over thirty in number, by A. 
Muller, Jaccard, Greppin, Moesch, Kaufmann, Escher, 
Theobald, Gillieron, Baltzer, Fritsch, Du Pasquier, 
Burckhardt, Quereau, Heim, Schmidt, Favre, Renevier, 
Gerlach, Schardt, Fellenberg, Rolle, Taramelli, and 
others. 
This is not the place to catalogue the separate 
