Page:Popular Science Monthly Volume 25.djvu/870

852 ingenuity. In the first plate, for instance, the property of center of gravity is illustrated in a dozen ways, some of them amusing, in a two-page picture, which itself has no inconsiderable merit as a composition. Other plates explain the principles of the mechanical powers of simple and compound machines, the parallelogram of forces, density, the fire-engine, pumps, watch and clock works, mills, distilling apparatus, house-heating apparatus, steam-engines, ship-construction, electricity and its applications, the aurora borealis, and acoustics and optics, and the instruments in which they are applied, or are made subjects of investigation.

one has done more to make the world acquainted with the regions of the Upper Nile and the Central African lakes than Sir Samuel Baker; and no one has conveyed the knowledge gained of them in a more entertaining and instructive manner than he. His two works, on "The Nile Tributaries of Abyssinia" and "The Albert Nyanza Great Basin of the Nile," are too large and expensive, and out of the reach of the mass of readers. The present volume has been condensed from them in such a manner as to omit that which is dry and only of detail, while the unity and thrilling charm of the narrative and the descriptive parts are retained.

purpose of this "Gazetteer" is to furnish in a convenient form such a concise dictionary of geography as will, from its special features and cheapness, prove acceptable and useful to the general public. It gives descriptions of the different countries of the globe, and of their physical aspects and political divisions, and the location of their principal towns, etc., with the pronunciation, and, in many cases, the etymology of the geographical names. The first edition of the "Gazetteer" was published in 1879. The present edition has been thoroughly revised, and much new matter has been added.

is the purpose of this work to present, in a systematic manner, all the most important facts relating to the economical production of sugar, sirup, and fodder from sorghum. The attempt is made to separate that which is demonstrable from the vast accumulation of statements, true and fanciful, that have been made since the plant was first introduced into the United States. The actual working results of numerous practical experiments in the production of sugar from this source have been given in detail, together with illustrations and descriptions of all necessary apparatus. The author's experience, as chemist of the United States Department of Agriculture, has given him excellent advantages for the study of different varieties of sorghum during all stages of development, the results of which he has endeavored to present, condensed and classified, in this volume. He has full faith in the possibility of making the production of sugar from sorghum profitable.

, infusing into his work the interest of a narrative and the easy grace of the informal essay, has given in this volume a series of sketches, more or less connected, on the different phases and events of married life, each of which, and the whole together, are intended to convey a moral or a salutary practical lesson.

statement of the general principles of the science occupies the opening pages of this little manual, and this is followed by notes as to the occurrence, preparation, properties, history, etc., of each of the non-metallic elements. It is adapted to accompany a course of laboratory work and lectures on this division of the elements.