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can be no doubt concerning the importance of using the right words in the right places; and any guide which approaches the subject in the right way and in the right spirit is of value. Mr. Ayres has given such a guide. He does not assume to be an authority, but a student of authorities and a representative of them. Following a strictly alphabetical arrangement of words and topics in regard to which a wrong usage exists or authorities differ, he gives in brief what the authorities declare about each, with their differences where they differ; and, while he does this with apparent impartiality, he is not afraid to add his own view, which, so far as we have noticed, is the one agreeable to reason and common sense. As a whole, "The Verbalist" is equal to the best of the small works in this department.

system of ventilation has been in use for several years, and has given general satisfaction as a cheap, simple, and effective method of solving the problem. It is adapted for any of the twenty or more kinds of buildings and apartments which he enumerates in his title-page, and can be applied with but little alteration of plans. The present volume gives an explanation of its operation, and a selection of miscellaneous paragraphs on the need of ventilation, good and bad ventilation, and the defects of modern buildings and modern life generally in respect to the subject.

work appears to be one of great value to amateur astronomers. Its purpose is to furnish the possessors of ordinary telescopes with plain directions for their use, and a list of objects for their advantageous employment. It begins with a description of the telescope, especially of ordinary telescopes (refractors of from three to five inches aperture, and reflectors of a little larger diameter), and directions for their practical care and use, after which are given descriptions of the sun, moon, planets, comets, and of the double stars, clusters, and nebulæ coming within the range of the class of observations contemplated. The account of the moon is accompanied with a large sheet-map, on which every point and object is distinctly marked and numbered, and that of Mars by a polar map of similar character. The chapter on double stars, clusters, and nebula?, is arranged by constellations, under the head of which each object is specifically and separately located and described.

is an example of the kind of work that an active mind of some ability may produce without having any of the knowledge that is gained by investigation and careful study. It offers a mixture of native ideas, some of which are good, with the utmost confusion of all that is taught by history and science. The author assumes that the great evils that afflict the world are land tenure, rents, interest, and the price of stocks—that is, all that furnishes the capital on which labor depends; and that it is the duty of labor to destroy these and establish a kind of communism. With all this he has some sound ideas on free trade and tariffs, and the spirit in which trades unions ought to be managed.

object of this treatise is to exhibit the elementary principles and notation of the quaternion calculus, so as to meet the wants of beginners in the class-room; and to give them such a conception of the value and beauty of this instrument of research as