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140 travel more speedily than the short ones. Waves at sea are mostly generated by wind, though other causes, such as earthquakes, occasionally operate. By blowing the surface of a long trough with a fan, the lecturer showed that the waves produced close to the source of the wind are shorter than those set up farther away. Oil has no effect upon big rollers, but the broken water on which it acts is just what is dangerous to boats in a tempest. A storm in mid-ocean generates waves of all lengths, but a kind of regularity is reached at a distance, where the long waves arrive first. The height of waves at sea has often been exaggerated, owing to the difficulty of measuring them, but the highest authentic observation is about forty feet. Stationary waves, as opposed to the progressive waves of which the lecturer had been speaking, were described as the results of the meeting of two equal sets of progressive waves. In illustration of the effects of waves upon ships, Lord Rayleigh showed a small model boat so weighted as to have the same rolling period as the waves in the tank in which it floated. Its rolling was exceedingly violent, but became comparatively slight when the heights were altered so as to change the rolling period. Warships, in which stability is very essential, are designed so as to have a longer period of roll than any waves they are likely to encounter.

Plymouth School of Applied Ethics.—The School of Applied Ethics at Plymouth, Mass, has had three profitable sessions—in 1891, 1892, and 1894; the session of 1893 having been omitted on account of the congresses at Chicago. At the first session, 1891, H. C. Adams, dean, the faculty numbered twenty-nine, and one hundred and sixteen lectures were given in the three departments of Economics, Ethics, and History of Religions. At the second session, Prof. C. H. Toy, dean, there were twenty-two lecturers and ninety-six lectures, in the three departments as before. At this session the Wednesdays were set apart for conferences and other special meetings—an experiment which was regarded favorably, but was not repeated during the next year. At the third session, 1894, Prof. Felix Adler, dean, there were thirty lecturers and one hundred and one lectures. The general subject in each of the three departments was the labor question, which was treated from various points of view, some of the lecturers being among the foremost political economists of our leading colleges and universities. The fourth session will begin in the second week in July, 1895, and will continue five weeks. An "Auxiliary Society of the School of Applied Ethics" has been formed, for the purpose, among others, of making the school and its work more widely known. Membership is open to all, for five dollars a year, and applications for it may be sent to the Rev. Paul R. Frothingham, New Bedford, Mass.

Indian Bows, Arrows, and Quivers.—In an interesting study of North American Bows, Arrows, and Quivers, published in the Smithsonian Report for 1893, Prof. Otis T. Mason shows how, in respect to either and all these appurtenances of the savage warrior and hunter, the form and material of the instrument and the manner of making n vary with and are dependent upon the kind of material which the local manufacturer had at his disposal. The bow is of hard wood, and simple, but of various forms according to fancy, in those regions where strong, elastic woods are abundant; compound, built up of buffalo or other horns in several pieces skillfully joined, where wood is scarce and the other material plenty; sinew-lined—finely shredded sinew mixed with glue being laid upon it so as to resemble bark—in the regions of the Sierras and as far north as the headwaters of the Mackenzie; sinew-corded, or having a long string or braid of sinew passing to and fro along the back, of which several types are found in the arctic and subarctic regions. The material of bows^varies geographically, and the list shows that in some regions some of the apparently most unpromising woods are used in their construction. The strings are of rawhide, the best vegetable fibers of the country, the intestines of animals cut into strings and twisted, or, most frequently, of sinew. The study is continued, with even more minutenes corresponding with the varieties of detail involved—concerning the head, the shaft, nocking, notching, and feathering—with the arrow. The quiver is difficult of study, because collectors have paid little attention to it. Among all the Plains tribes the quivers are