Page:Popular Science Monthly Volume 32.djvu/137

Rh hands. The section on the general structure and geological history of the earth has been prepared by Dr. John S. Newberry, Professor of Geology and Paleontology in Columbia College; that devoted to the geological history of the North American Continent, by Professor Charles H. Hitchcock, of Dartmouth College; the portion relating to general physiology and the physical features of the United States, by Mr. Henry Gannett, Chief Geographer of the United States Geological Survey; the pages explaining terrestrial magnetism, with the chapters on volcanoes and earthquakes, coral islands, the earth's waters, and meteorology, by Dr. W. Le Conte Stevens, Professor of Physics in the Packer Collegiate Institute. Dr. N. L. Britton, Lecturer in Botany, Columbia College, furnished the chapter on plant-life; Dr. C. Hart Merriam, the Ornithologist of the Department of Agriculture, those relating to zoölogy and the animal life of the United States; Professor William H. Dall, of the Smithsonian Institution, that on etimologyetymology [sic]; and Mr. George F. Kunz, gem expert and mineralogist with Messrs. Tiffany & Co., of New York, that on precious stones. Throughout the book references to standard works have been inserted, which will guide pupils and teachers to fuller sources of information on the various topics which can be only touched upon in a school text-book. The text is copiously illustrated with pictures, diagrams, and maps in color, on which no pains have been spared to secure accuracy and mechanical excellence.

applications of new chemical discoveries to technical purposes have become so frequent during the last quarter of a century as to cause almost a complete change in several important branches of modern industry, developing new fields of human application and effecting marked improvements in manufacturing generally. Like other industries, the colorist branch, which may be said to be the pet child of modern chemical investigation, has not been slow to feel the effect of the introduction of scientific methods in the every-day work of the factory; the result has been a steady progress and improvement in the methods of obtaining colors on fabrics, consequent on the introduction of new coloring-matters and a better understanding of the properties of the substances used, and of the principles which govern the formation and fixation of each color on the fiber.

The printing of tissues—that is, the art of fixing various colors which form more or less elaborate designs on cloth—is a very complicated process, requiring for its successful completion the assistance of all the skill which chemical and mechanical progress has placed at the service of manufacturers. This progress, however, which permits of greater facilities being introduced gradually, rendering possible the adoption of novel and more complicated designs which could not be easily employed with older methods, makes it at the same time imperative on those engaged in this branch of industry to keep themselves posted on all the forward steps made by others, in order to meet the artistic requirements of the consumer, and the competition of rival manufacturers.

This progress is so steady and gradual that it has to be followed incessantly. Publications treating specially of this branch of manufactures are not very plentiful; the continual changes and improvements are liable to deprive a book of its practical usefulness a few years after its publication. A complete work on the subject, embodying the latest devices and processes in use, can, therefore, not help being welcome both to the trained colorist and to the student. The author is well fitted for the task he has undertaken, having been for several years director of the School of Dyeing and Printing at the Technical School of Manchester, the center of the printing industry.

Theory and practice are given an equal share of attention, which they both deserve in an art in which scientific training, skill, experience, and artistic taste have all to contribute to the result. The opening chapter is devoted to the history of calico-printing which is traced from its origin in India, to its present flourishing expansion.

Before the tissue can actually be printed upon, it is necessary that it should be bleached; to this important Preliminary