mined the latitude and longitude
of the mountain, measured the slope of the cone, and the diameter of the
great crater, and minutely examined the structure of the rocks at the
base of the mountain. He also gives a good sectional view, elevations
taken from each quarter of the compass, and a geological map, which
although accurate in its general details, can scarcely be considered
very satisfactory. A relief map of Etna, a copy of which is in the Royal
School of Mines, was afterwards constructed from the flat map, and this
was, we believe, at the same time, the first geological map, and the
first map in relief, which had been made of the mountain. Elie de
Beaumont considers granite as the basis of the mountain, because it is
sometimes ejected from the crater; old basaltic rocks appear in the
Isole dei Ciclopi, and near Paterno, Licodia, and Aderno; _cailloux
roules_ near Motta; ancient lavas on each side of the Val del Bove;
modern lavas in every part of the mountain, and calcareous and
arenaceous rocks in the surrounding mountains.

[11] Printed in vol. IV. of _Memoires pour servir a une description
Geologique de la France_. Par M.M. Dufrenoy et Elie de Beaumont.

In 1836, Abich published some excellent sections of Etna, and an
accurate view of the interior of the crater, in a work entitled _Vues
illustratives de quelques Phenomenes Geologiques prises sur le Vesuve et
l'Etna pendant les annees 1833 and 1834_.

The whole of the thirteenth volume (1839) of the Berlin _Archiv fuer
Mineralogie, Geognosie, Berghau und Huettenkunde_, is occupied by an
elaborate memoir on the geology of Sicily[12] by Friedrich Hoffmann,
accompanied by an excellent geological map. A long account of the
geology of Etna is given, and an enlarged map of the mountain was
afterwards constructed and published in the _Vulkanen Atlas_ of Dr.
Leonhard in 1850.[13]

[12] Entitled _Geognostiche Beobachtungen Gesammelt auf einer Reise
durch Italian und Sicilien, in den jahren 1830 bis 1832, von Friedrich
Hoffmann_.

[13] _Vulkanen Atlas zur naturgeschichte der Erde von K. G. Von
Leonhard._ Stuttgardt. 1850.

In 1836 Baron Sartorius Von Waltershausen commenced a minute survey of
Etna, preparatory to a complete description of the mountain, both
geological and otherwise. He was assisted by Professor Cavallari of
Palermo, Professor Peters of Hensbourg, and Professor Roos of Mayence.
The survey occupied six years, (1836-1842), and the results of direct