Page:Popular Science Monthly Volume 56.djvu/137

Rh required for perception, "hearing in school," the influence of habit and attention, orientation of the sound, bilateral sensations, effects on the nervous centers, etc., hearing of musical sounds, oscillations and aberrations of hearing, auditive memory, obsessions, hallucinations of the ear, and colored audition.

Prof. Andrew C. McLaughlin's History of the American Nation has many features to recommend it. It aims to trace the main outlines of national development, and to show how the American people came to be what they are. These outlines involve the struggle of European powers for supremacy in the New World, the victory of England, the growth of the English colonies and their steady progress in strength and self-reliance till they achieved their independence, the development of the American idea of government, its extension across the continent and its influence abroad—all achieved in the midst of stirring events, social, political, and moral, at the cost sometimes of wars, and accompanied by marvelous growth in material prosperity and political power. All this the author sets forth, trying to preserve the balance of the factors, in a pleasing, easy style. Especial attention is paid to political facts, to the rise of parties, to the development of governmental machinery, and to questions of government and administration. In industrial history those events have been selected for mention which seem to have had the most marked effect on the progress and make-up of the nation. It is to be desired that more attention had been given to social aspects and changes in which the development has not been less marked and stirring than in the other departments of our history. Indeed, the field for research and exposition here is extremely wide and almost infinitely varied, and it has hardly yet begun to be worked, and with any fullness only for special regions. When he comes to recent events, Professor McLaughlin naturally speaks with caution and in rather general terms. It seems to us, however, that in the matter of the war with Spain, without violating any of the proprieties, he might have given more emphasis to the anxious efforts of that country to comply with the demands of the administration for the institution of reforms in Cuba; and, in the interest of historical truth, he ought not to have left unmentioned the very important fact that the Spanish Government offered to refer the questions growing out of the blowing up of the Maine to arbitration and abide by the result, and our Government made no answer to the proposition.

Mr. W. W. Campbell's Elements of Practical Astronomy is an evolution. It grew out of the lessons of his experience in teaching rather large classes in astronomy in the University of Michigan, by which he was led to the conclusion that the extensive treatises on the subject could not be used satisfactorily except in special cases. Brief lecture notes were employed in preference. These were written out and printed for use in the author's classes. The first edition of the book made from them was used in several colleges and universities having astronomical departments of high character. The work now appears, slightly enlarged, in a second edition. In the present greatly extended field of practical astronomy numerous special problems arise, which require prolonged efforts on the part of professional astronomers. While for the discussion of the methods employed in solving such problems the reader is referred to special treatises and journals, these methods are all developed from the elements of astronomy and the related sciences, of which it is intended that this book shall contain the elements of practical astronomy, with numerous references to the problems first requiring solution. The author believes that the methods of observing employed are illustrations of the best modern practice.

In The Characters of Crystals Prof. Alfred J. Moses has attempted to describe, simply and concisely, the