Page:Popular Science Monthly Volume 18.djvu/723

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An Elementary Course of Geometrical Drawing: Containing Problems on the Right Line and Circle, Conic Sections and other Curves; the Projection Section and Intersection of Solids; the Development of Surfaces and Isometric Perspective. By George L. Vose, A. M., Professor of Civil Engineering in Bowdoin College. Illustrated by Thirty-eight Plates. Boston: Lee & Shepard.

This seems to be an excellent introduction to the practice of geometrical drawing. Its method has been used for several years in classes with the most favorable results. It was prepared for the use of the lower classes in engineering schools, but parts of it may no doubt be made excellent use of in the high schools. The author claims that it is well adapted for those who desire to pursue this branch of study by themselves and without a teacher. But he strongly recommends pupils to commence with a master wherever practicable, as they will thus save time, and avoid the formation of bad habits, so easy to get and so hard to lose.

Among Machines. A Description of Various Mechanical Appliances used in the Manufacture of Wood, Metal, and Other Substances. A Book for Boys. Copiously illustrated by the author of "The Young Mechanic." New York: G. P. Putnam's Sons. Pp. 335. Price, $1.75.

On the extensive subject of machinery, which would fill cyclopædias, this volume takes up only such parts as are assumed to have a general interest, and concerning which it is well that all active-minded boys should be instructed. It treats of those fundamental laws which underlie the system of machinery, and upon which are founded the various mechanical combinations which have contributed so much to the development of manufactures. The need of understanding these principles would be apparent, and we remember that hand processes are rapidly disappearing by the substitution of machinery, so that the mechanic who has been trained to a special manipulation hardly knows at what moment an unexpected invention may undermine and destroy his vocation. Each new victory and invention is, moreover, but a step toward others, and we are every day surprised to observe how triumphant ingenuity has overcome difficulties hitherto supposed to be insurmountable, and which makes an inroad upon the traditional handicraft labor, and cheapens a product of general utility. The author of this book, therefore, thinks it a fit time to instruct the younger portion of the community in the details of the more ordinary machines with which they may perhaps some day become closely and personally interested. Twenty chapters are devoted to the most important machines, processes, and mechanical arrangements in the wide field of manufacturing industry.

Telegraphic Determination of Longitudes on the East Coast of South America. By Lieutenant-Commanders F. M. Green, C. H. Davis, and Lieutenant J. A. Norris, U. S. N., in 1878 and 1879. Published by order of Commodore William D. Whiting, U. S. N., Chief of the Bureau of Navigation, Navy Department. Washington: Government Printing-Office. Pp. 87.

The longitude of points on the east coast of South America has been very uncertain until recently, for the results obtained by apparently trustworthy methods have differed by almost incredibly large quantities. The extension of telegraphic cables gave the opportunity to make more accurate determinations from some well-determined point in Europe by way of Madeira and the Cape Verd Islands with the eastern South American coast. The connection was made from Land's End by Carcavellos, at the mouth of the Tagus, and the Brazilian submarine telegraph. The determinations made by the commission, combined with the determinations of meridian distances made by Professor Gould at Cordova, furnish a valuable system of longitudes embracing about twenty stations in the interior. A curious fact connected with this work is, that it has given the first correct determination of the longitude of Lisbon.

The Relations of Science to Modern Life. A Lecture delivered before the New York Academy of Sciences. By Henry C. Potter, D. D. Published by the Academy. New York: G. P. Putnam's Sons. Pp. 29.

The author presents, in the easy, flowing style of a popular lecture, a view of the obligations we are under to science in the commoner features of our domestic and social life.