CURRENT LITERATURE.
Six Lectures on Physical Geography. By the Rev. Samuel Haughton, M.D., F.R.S. (Dublin : Hodges, Foster, and Figgie.)- " The Past History of our Globe, and its Future Prospects ;" " Con- tinents and Oceans ;" " Mountains and Volcanoes ;" " Rivers and Lakes ;" " The Laws of Climate and Atmosphere," with " The Dis- tribution in Space and Time of Animals and Plants," —such are the large and varied subjects which Dr. Haughton handles in the volame before us. The original six lectures have now grown into a volume of nearly 400 pages, illustrated with more than a score of tables, maps, and diagrams. To give a just notion of the contents of this book, and of the mode of treatment which Dr. Haughton has adopted, would demand far more space than we can here afford. We must content ourselves with a general recommendation of these lectures, which are interesting not only by reason of the subjects on which they treat, but also because of the extraordinary industry with which the facts and figures they contain have been collected, and the extreme ingenuity with which these data have been made to serve as bases for the arguments and hypotheses of the author. The reader is constantly meeting with such calculations as this (p. 79),—A layer of coal 3 in. thick, or a layer of limestone 15 in. thick, spread uniformly over the globe, if volatilised by heat, would develope four per cent. of carbonic acid in the atmosphere, and immediately destroy alt the warm-blooded animals on the surface of the globe. Or again, we may learn if we will (p. 160), the total amount of heat received from the sun at various latitudes during the course of a year ; and we shall find that it may be represented by an average thickness of SO ft. of ice, melted over the whole globe. Now, of this heat, the amount lost by radiation would melt 28f ft. of ice, and thus we have heat sufficient to melt 51} ft. of ice available for and used in the geological work done by air, rain, and rivers, and in the chemical and vital work performed in the animal and vegetable organisms upon the earth. Calculations such as these, many of them original and all most carefully elaborated abound in Dr. Haughton's pages. But the interest of his work centres in the use he makes of such figures ; while a lively style, which does not exclude narratives of travel and descriptions of natural marvels, makes the volume agreeable reading.
Previous page
