140 



THE POPULAR SCIENCE MONTHLY 



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 sur- 

 face 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 tem- 

 pest. 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 diffi- 

 culty of measuring them, but the highest 

 authentic observation is about forty feet. 

 Stationary waves, as opposed to the progress- 

 ive 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 sta- 

 bility 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 con- 

 gresses at Chicago. At the first session, 1891, 

 H. C. Adams, dean, the faculty numbered 

 twenty-nine, and one hundred and sixteen lec- 

 tures 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 be- 

 fore. 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 lectur- 

 ers and one hundred and one lectures. The 

 general subject in each of the three depart- 



ments was the labor question, which was 

 treated from various points of view, some of 

 the lecturers being among the foremost po- 

 litical 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 war- 

 rior and hunter, the form and material of the 

 instrument and the manner of making n vary 

 with and are dependent upon the kind of ma- 

 terial 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 skill- 

 fully 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 re- 

 gions 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 sub- 

 arctic 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 con- 

 struction. The strings are of rawhide, the 

 best vegetable fibers of the country, the in- 

 testines of animals cut into strings and twisted, 

 or, most frequently, of sinew. The study is 

 continued, with even more minutenes corre- 

 sponding 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 col- 

 lectors have paid little attention to it. 

 Among all the Plains tribes the quivers are 



