274 



THE POPULAR SCIENCE MONTHLY. 



and technical discussions have been for the 

 most part excluded from the body of the 

 work and printed at the end of the volume 

 in notes. The wider application than that to 

 the special object of the research of which 

 many discoveries are susceptible is illus- 

 trated in the modern very general use by 

 farmers and fruit-growers, in all parts of 

 the country, of pyrethrum in the field, of 

 petroleum emulsions, and of the cyclone 

 spraying-nozzle, all of which have had their 

 origin in this investigation. The report 

 gives a full account of the cotton-worm, its 

 character, habits, and history ; of the influ- 

 ences that affect it, its natural enemies, the 

 preventive measures to be taken against it, 

 and the remedies, and machinery, and de- 

 vices for accomplishing its destruction ; a 

 chapter on the boll-worm ; and a number 

 of special reports in the Appendix. 



Duffy's Wave-Motor as a Source of Tow- 

 er for Various Purposes. By Ter- 

 ence Duffy. San Francisco: 948 Ger- 

 ry Street. Pp. 15. 



Mr. Duffy has sought an invention to 

 utilize the enormous energy of waves as a 

 source of power, and for the movement of 

 mechanism. He has devised a buoy, with 

 internal arrangements and machinery by 

 which a set of pumps shall be set in motion 

 by the undulations to which it is subjected, 

 to supply a reservoir of compressed air ; 

 this air to be applied to any purpose for 

 which it may be desired. Among the ap- 

 plications suggested in the pamphlet are 

 the generation of electricity; signal, relief, 

 and light stations ; propulsion of vessels ; 

 and the movement of machinery on shore. 

 The structure of the buoy, with all its cham- 

 bers and mechanism, and the application to 

 these purposes, are set forth in the pamphlet. 

 We see nothing in the text, however, from 

 which we are enabled to affirm that the au- 

 thor has set up one of his buoys and put it 

 to an experimental test. 



The American Journal of Biology. Quar- 

 terly. Edited by II. D. Valin, M. D. 

 Chicago: Published by the author. $1 

 a year. 



The "Journal," according to the edi- 

 tor's prospectus, is devoted to the study of 

 life and mind in its widest sense, and will 

 consist mainly of articles written especially 



for its pages by persons competent to treat 

 the subject. Each number is intended to 

 contain sixty pages. The present number 

 is published with only forty-four pages, but 

 with a promise to make up the deficiency in 

 the next number, which will consist of sev- 

 enty-six pages. It contains papers on " The 

 Laws of Life outlined," " Origin of Flow- 

 ers," " Nature of Animal Colors," " Nature 

 of Light," " Development of the Eye," and 

 " Nature of Sight," and selections. 



Mechanics of the Girder. A Treatise on 

 Bridges and Roofs. By John Daven- 

 port Crehore, C. E. New York : John 

 Wiley & Sons. Pp. 575. Price, $5. 



In this purely technical treatise, the 

 necessary and sufficient weight of the struct- 

 ure is calculated, not assumed ; and the 

 number of panels and height of girder that 

 render the bridge-weight least for a given 

 span, live load, and wind-pressure, are de- 

 termined. The book is presented just as 

 it was left at the author's death, in October, 

 1884, with the carrying out of only a few 

 examples in the twelve classes of girders 

 still remaining to be done. Of these exam- 

 ples, the post-truss promised to yield the 

 most prolific results ; and it may be possible, 

 the editor hopes, " before another edition is 

 published, to complete this calculation at 

 least, if not to introduce other examples 

 from the later classes. However, the a priori 

 method of the author is fully set forth pre- 

 vious to the tenth chapter ; and it is be- 

 lieved that no one else has as yet published 

 any so satisfactory results from this meth- 

 od, if, indeed, the method has been hitherto 

 attempted with any degree of success." The 

 work has been prepared for the press un- 

 der the supervision of Professor John N. 

 Stockwell, who has also undertaken the task 

 of completing the remaining examples for 

 future editions. 



Bulletin of the United States Geological 

 Survey. Nos. 27, 28, and 29. Washing- 

 ton : Government Printing-Office. I'p. 

 80, 59, with Plates and Map, and pp. 24, 

 with Plates. 



No. 27 is an account of the work done in 

 the division of Chemistry and Physics, main- 

 ly dming the year 1884-'85. Among the 

 papers arc one on " Topaz from Stoncham, 

 Maine " ; a memoir, by F. A. Gooch, on the 



