ENGINEER DIPLOMATIST, TRIN. COLL. DUBLIN; MEMBER OF THE ROYAL IRISH ETC. ETC. LONDON: ROBERT HARDWICKE, 192, PICCADILLY. 1873. PREFACE. the is WANT expressed by many Geologists and often felt by the Author, is a classified HANDY-BOOK OF ROCK NAMES. It is hoped that, until a better appears, this Manual may be useful to the Public. same To write such a work satisfactorily is no easy task. In other branches of Natural Science, such as Botany, Zoology, and the like, some systematic nomenclature has been followed, but in Geology no one system has been used, or all system has been ignored. It is not uncommon to find eminent Petrologists calling the rock by several names, or, what is more perplexing, using for a rock a name already given to a totally different one. At the present time Rock names are in such confusion that if an observer names a rock, without at the same time mentioning his authority, he may be supposed to be referring to a rock, or even rocks, totally different to that which he intended to illustrate. This irregularity has caused many names to be used, not only unscientifically but also absurdly, as the original name may refer to a mineral or character not possessed by the rock or rocks to which it is now applied. From the above it is evident that a compiler of such a book as this Manual must run contrary to the opinions and |