REVIEWS 521 



has been given to the logical development of the subject, and care has been taken 

 to point out the limitations of the different theories ; emphasis being laid on the 

 divergence of the conditions met in practice from the ideal conditions under 

 which the theoretical formulas are deduced, and on modifications necessary, or 

 advisable, when the formulas are used under ordinary working conditions" — is 

 more than justified. 



Indeed, these points in particular, no less than the general treatment through- 

 out, stamp the volume as being in a class by itself. 



With very little addition the work carried out on such sound lines " for the 

 use of students in the Departments of Engineering in the Massachusetts Institute 

 of Technology " would be of the greatest value in the library of the engineer. 



The chief addition would be with respect to (a) the actual testing of materials, 

 (b) working stresses. 



Thus, "hardness" is defined on p. 2. No mention, however, is made of the 

 methods of testing hardness. There can be no question that an outline of 

 the chief tests of materials, in a book on " the strength of materials," would be 

 of value to the student as well as to the engineer. In the same way a tabulation 

 of "working stresses" and the methods of determining same would be a great 

 help to the designer in college no less than to the more mature designer in 

 practice. We contend that there are many important points discussed in this 

 volume the full significance of which the mere student could not be expected to 

 realise — more particularly, those modifications of theory so necessary in practice. 

 The engineers, in practice, would welcome the help given them on these points, 

 which form so strong a feature of the book. We have no hesitation in recom- 

 mending the volume to students and engineers alike. 



J. Wemyss Anderson. 



MISCELLANEOUS 



A Century of Science in America. By Edward Salisbury Dana and other 

 writers. [Pp. xi + 458, with 22 portrait plates.] (New Haven : Yale 

 University Press; London: Oxford University Press, 19 18. Price17j.net.) 



This volume contains the fourteenth course of the Silliman Memorial Lectures, 

 which were inaugurated in 1901 by the Corporation of Yale University when it 

 came into possession of the legacy of $80,000 given by the children of Mrs. 

 Hepea Ely Silliman, in 1883, as a memorial of their mother. It commemorates 

 the hundredth anniversary of the foundation of the American Journal of Science 

 by Benjamin Silliman, who at the time occupied the chair of chemistry and 

 mineralogy at Yale College. 



The first chapter of the book contains an account of the history of this Journal '. 

 It appears that its inception was due to Colonel George Gibbs, whose famous 

 collection of minerals was purchased by Yale in 1825. Benjamin Silliman rather 

 reluctantly consented to act as editor, for he recognised the difficulties which 

 then confronted the holder of such an office and the demands it would make 

 on his time. He had a twofold problem to solve : not only had an audience 

 to be found among a public little interested in science, but also material to fill 

 his pages. The original " Plan of Work" was for these reasons most com- 

 prehensive, including not merely all branches of science, but all the applied arts 

 as well. Just at first progress was very slow, and in his preface to the fourth 

 volume the editor, who had by now assumed pecuniary responsibility for his 



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