Smith, the father of English Geology, loved to remark that he had been born upon the Oolite--the formation whose various deposits he was the first to distinguish and describe, and from which, as from the meridian line of the geographer, the geological scale has been graduated on both sides. I have thought of the circumstance when, on visiting in my native district the birthplace of the author of the _Silurian System_, I found it situated among the more ancient fossiliferous rocks of the north of Scotland--the Lower Formation of the Old Red Sandstone spreading out beneath and around it, and the first-formed deposit of the system, the Great Conglomerate, rising high on the neighboring hills. It is unquestionably no slight advantage to be placed, at that early stage of life, when the mind collects its facts with greatest avidity, and the curiosity is most active, in localities where there is much to attract observation that has escaped the notice of others. Like the gentleman whom I have now the honor of addressing, I too was born on the Old Red Sandstone, and first broke ground as an inquirer into geological fact in a formation scarce at all known to the geologist, and in which there still remains much for future discoverers to examine and describe. Hence an acquaintance, I am afraid all too slight, with phenomena which, if intrinsically of interest, may be found to have also the interest of novelty to recommend them, and with organisms which, though among the most ancient of things in their relation to the world's history, will be pronounced new by the geological reader in their relation to human knowledge. Hence, too, my present opportunity of subscribing myself, as the writer of a volume on the Old Red Sandstone, Honored Sir, With sincere gratitude and respect, Your obedient humble Servant, HUGH MILLER. Edinburgh, _May_ 1, 1841. PREFACE. Nearly one third of the present volume appeared a few months ago in the form of a series of sketches in the _Witness_ newspaper. A portion of the first chapter was submitted to the public a year or two earlier, in _Chambers's Edinburgh Journal_. The rest, amounting to about two thirds of the whole, appears for the first time.