PREFACE. I did not set about this work under the persuasion that I was the most fitting person for a task so arduous; or that I possessed either the necessary facilities for so wide a field of Statistics, or could appropriate sufficient time to its preparation. The fact is, at the outset, it was the result almost of necessity; a preparation for temporary and specific purposes, of a series of comparative details relating to the coal trade of the United States and of certain other countries. The information required was not accessible in any single work, nor even in a number of works; it was no where to be found. The materials, therefore, had to be collected and arranged by degrees, and to be drawn from original sources; and in this manner, the data sought for became the nucleus which has gradually expanded into the substance and capacity of a considerable volume. Of the incompleteness, the multifold imperfections of such a work, especially its first edition; the tendency to error; the innumerable gaps and blanks that remain to be filled up, no one can be so well aware, probably, as its author. An unequal acquisition of statistical details is the inevitable result of all such undertakings. It will not, we admit, be difficult to point out these deficiencies, and critics may suggest abundant omissions and emendations, in this volume. However, as there must be some limit to the accumulative process and some cessation from the collector's toil, it has now become necessary to bring it to a close, and to commit it to the indulgence of the public. R. C. T. CONTENTS OF THE INTRODUCTION. Introductory Sketch.-Proportionate areas of coal land in Europe and America.- Proportionate areas of coal formations in the United States.-General summary of coal statistics.-Europe.-United States of America.-Production of combustibles. -Summary of statistics of mineral fuel.-Increased production of American coal Page Miscellaneous notes in relation to coal.-Geographical distribution of coal.-Com- parative value of gold and silver, and of coal and iron.-Employment of mineral combustibles.-Geological position of coal beds.-Local position and arrangement of beds of coal.-Accidents, faults, and irregularities of coal beds.-Varieties of coal, with reference to their adaptation to the making of iron.-Classification of mineral coals. Adaptation of different varieties of coal to the purposes of steam navigation.-Adaptation of coal to steam power.-Depths of coal mines.-Systems for working coal mines.-Ventilation of coal mines.-Means to destroy or check the fire-damp or grisou in subterranean works.-Local ventilation.-Ventilation of fiery collieries.-Ventilation of collieries in Scotland and the north of England.- Medical treatment after explosion.-Drainage of coal mines.-Tracing of coal beds in the anthracite districts of Pennsylvania.-On the maps or plans of mines.- Fossil botany and geological distribution of vegetable remains.-Fossil botany:- Cotyledoneæ.-I. Dicotyledonea.-II. Monocotyledoneæ.-III. Acotyledoneæ, or imperfect.-Microscopic observations on the structure of coal, lignite and peat.- Miscellaneous notes as to coal and fossil vegetation.-Usual position of stigmariæ, |