362 



SCIENCE. 



[Vol. XVI. No. 412 



mostly well disposed of. But some of the germs may find the 

 proper soil, multiply, and cause disease Of such diseases, con- 

 sumption is by far the most deadly, and the one most easily 

 spread, since the germs are being constantly scattered in the spu- 

 tum in streets, public buildings, and public conveyances. Con- 

 sumption is, however, preventible, and to this end the destruction 

 of the sputum would distinctly tend. The author's severe stric- 

 tures of the street-cleaning department are fully justified. " We 

 virtually condone manslaughter just as long as we permit men to 

 hold municipal offices who fail in their plain duty in the protec- 

 tion of the public health." 



Germ laden dust readily finds its way into private rooms: 

 hence, after sweeping, the furniture and floor should be cleaned, 

 not dusted. "Dust and its Dangers"' is an excellent, suggestive, 

 and temperate little book. 



AMONG THE PUBLISHERS. 



Among the features of Outing for January, 1891, are " Arti- 

 ficial Skating Ponds," by C. Bowyer Vaux, who teaches our boys 

 how nature can be " coached " into the skater's service; and " Sail- 

 ing on Skates," and the method of rigging up such an outfit. 



— The D Van Nostrand Company of this city have published, 

 in a neat octavo of a hundred pages, a work on "Maximum 

 Stresses under Concentrated Loads, treated Graphically," by 

 Henry T. Eddy, C.E., Ph.D., professor of mathematics and civil 

 engineering in the University of Cincinnati. It is a reprint from 

 the "Transactions of the American Society of Civil Engineers," 

 and is illustrated by twenty-five figures in the text and one folding 

 plate. The object of the work, as stated by the author, is to in- 

 troduce a new graphical method for determining what position a 

 moving train of wheel weights must have in order to produce the 

 greatest stress in any given part of the bridge truss or girder over 

 which the train is passing. The method proposed depends princi- 



pally upon the construction and use of a class of polygons or 

 curves named by the author "re-action polygons." These are 

 readily constructed graphically, and their properties are such as to 

 give with ease the train positions for maximum stresses as well as 

 to decide which one of several maxima is the greatest. The proof 

 of these constructions is given in algebraic form, the graphical 

 constructions being really only representations of the algebraic 

 conditions for maximum stresses. The treatise shows how the 

 algebraic theory leads to convenient graphical solutions of the 

 equations of condition for maximum stresses, and will prove a 

 serviceable addition to the growing literature of bridge engineer- 

 ing. 



^In The Chautauquan for January. 1891, may be found "The 

 Intellectual Development of the English People," by Edward A. 

 Freeman; " The English Constitution," IV., by Woodrow Wilson; . 

 "England after the Norman Conquest," Parti., by Sarah Orne 

 Jewett; "The English Towns," by Augustus I. Jessopp, D.D. ; 

 "Studies in Astronomy," IV., by Garrett P. Serviss; "How the 

 People are t'ounted," by H. C. Adams; and " Plants in Legends," 

 by Dr. Ferd. 



— The American Book Company have just published " Greek 

 for Beginners," by Edward G. Coy, professor of Greek in Phillips 

 Academy. It is intended to he a companion book to the Hadley- 

 Allen "Greek Grammar," and to be used as an introduction to 

 either Coy's " First Greek Reader" or the Anabasis of Xenophon. 

 A book bearing the same title, prepared by Professor Joseph B. 

 Mayor, was published in London in 1869. An American edition 

 of that book, considerably altered in form, was published in 1880 

 as " Coy's Mayor's Greek Lessons." The book now issued is a re- 

 vision of the last-named edition, but the changes introduced by 

 Professor Coy are so numerous and extensive, that, in justice to 

 both Professor Mayor and himself, he has deemed it advisable to 

 assume the entire responsibility for the work. He has therefore 



JUST PUBLISHED. 8vo, $4.00. 



THE MYOLOGY OF THE RAVEN 



{CORVUS COR AX SINDATVS). 



A GUIDE TO THE STUDY OF THE MUSCULAR SYSTEM IN BIRDS. By R. W. Shupeldt. With numerous illustrations. 8vo, 



$4.00. 



" We can congratulate Dr. Shufeldt on the production of an original and well-arranged text-booh, the result of much patient labour in col- 

 lecting and dissecting, and careful thought in arrangement. The volume uill appeal especially to ornithologists, as well as to students of compara- 

 tive anatomy. The figures, of which there are 76, are on the whole excellent, and with few exceptions are original. A copious bibliography and 

 index are given at the end if the 600ft."— Nature. 



SUBSCRIBE NOW FOR THE YEAR 1891. 



NATURE: 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. Weekly, price, 15 cents. Annual Subscription, $6.00. Sent two months as a 

 trial subscription on receipt of $1.00. 



" Nature is recognized everywhere as the foremost scientific journal, of a general character, in the world." — N. Y. Evening Post. 



"The one journal indispensable to students in every branch and every land." — Popular Science Monthly. 



*' That Natuke has completed its twentieth year is subject of congratulation on the part of the whole scientific world." — Evening Post. 



Tycho Brahe. A picture of scientific life and work in the six- 

 teenth century. By J. L. E. Dretbr, Ph.D., F.R.A.S. With 

 illustrations. 8vo, $3.50. 

 "A most valuable contribution to the history of mediBBval astronomy; it 

 is creditably exempt from slips and inaccuracies of memory, pen or print; 

 abounds with bibliographical knowledge and indications; and— not its least 

 merit — is furnished with a highly serviceable index. It portrays, moreover, 

 with perfect candour, yet full comprehension and sympathy, a vigorous and 

 picturesque individuality." — Nature. 



The Meteoritic Hypothesis. A statement of the results of a 

 spectroscopic inquiry into the origin of cosmical systems. By 

 J. NoEMAN LoCKTEE, F.R.S., etc., etc. With numerous illas- 

 trations. 8vo, $5.25. 



Macmillan's Physical and Political School Atlas. A series of 

 eighty maps with general index. By J. G. Baetholomew, 

 F.R.S.E., F.R.G.S. $3.00. 



Are the Effects of Use and Disuse Inherited ? An Examination 

 of the views held by Spencer and Darwin. By William Platt 

 Ball. 16mo, $1.00. 



"The questions dealt with in Dr. Ball's clearly reasoned and ingenious 

 little book, are not merely interesting from a speculative point of view, but 

 upon their solution depend social problems of the first importance. The 

 views set forth by the author coincide in large measure with the theory of 

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 Tribune. 



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