Volcanoes: What They are and What They Teach

THE
International Scientific Series
VOL. XXXV.
Frontispiece.
Sections of Igneous Rocks, illustrating the passage from the glassy to the crystalline structure.
1. Vitreous Rock. 2. Semi-Vitreous Rock. 3. Vitreous Rock with Sphærulites. 4. Rock with Crypto-crystalline Base. 5. Rock with Micro-crystalline Base. 6. Rock of Granite Structure built up entirely of Crystals.
PROFESSOR OF GEOLOGY IN THE ROYAL SCHOOL OF MINES
WITH 96 ILLUSTRATIONS
SIXTH EDITION
LONDON KEGAN PAUL, TRENCH, TRÜBNER & CO. Ltd. PATERNOSTER HOUSE, CHARING CROSS ROAD 1903
( The rights of translation and of reproduction are reserved. )
In preparing this work, I have aimed at carrying out a design suggested to me by the late Mr. Poulett Scrope, the accomplishment of which has been unfortunately delayed, longer than I could have wished, by many pressing duties.