[Illustration: BASALTIC COLUMNS AT REGIA, IN MEXICO ] GEOLOGICAL FACTS; OR, THE CRUST OF THE EARTH, WHAT IT IS, AND WHAT ARE ITS USES. BY THE REV. W. G. BARRETT, ROYSTON. “There is in this universe a stair, or manifest scale of creatures, rising not disorderly nor in confusion, but with a comely method and proportion.”—SIR THOMAS BROWNE, _Religio Medici_, 1642. LONDON: ARTHUR HALL, VIRTUE, & CO. 25, PATERNOSTER ROW. 1855. LONDON: R. CLAY, PRINTER, BREAD STREET HILL PREFACE. Last written, and generally last read, a Preface has nevertheless become so integral a part of every book, that I may presume, I trust, upon the attention of my readers while I ask them to indulge me with a little prefatory egotism. This book of mine goes forth into the world with many misgivings on the part of its author. How he came to write it was thus-wise. He was settled in a quiet country town in Cambridgeshire, Royston to wit, as a Dissenting Minister; around him he found a number of young persons, who did not believe they had “finished their education” because they had left school, and who were anxious to avoid the usual littleness and small talk of such towns, by earnest attention to actual study. And so it came to pass that a Geological class was formed, which, meeting every week, afforded real stimulus for private work, and led to the consultation of the best standard works, happily available through the well-conditioned library of the town. The result of those classes is this little book. What is written here was mostly, if not all, said there; and, urged to publish, the author feels a pleasure in dedicating this book to the class, composed almost entirely of young ladies, who found in these studies one of their chief delights, and whose private collections have been greatly assisted by the hints thus obtained. I do not pretend to _teach the Science of Geology_; I aspire simply to give a taste for this noble and elevating physical study; and, imperfect as this little manual, written in the few hours of capricious leisure snatched from an incessant strain of engagements, must be, I shall only be too happy, if one and another lay aside _my_ book, and go up higher to Lyell, Sedgwick, Buckland, Murchison, Ansted, Miller, and others.