634 



SCIENCE. 



[N. S. Vol. I. No. 3a 



SCIENTIFIC LITEEATUEE. 

 The Mechanical En(jineer''s Pocket Booh. By 



Wm. Kent. New York, J. Wiley & 



Sons, 1895. 168 illustrations, pp. xxxi.; 



1087, 16 mo. $5.00. 



This ' pocket-book,' although altogether 

 too large for the pocket — as are, in fact, all 

 these books, when meeting the require- 

 ments fully — is the most important and 

 valuable accession to the portable library 

 of the engineer that has recently appeared. 

 Its scope is purposely confined to those 

 subjects which are of main interest to the 

 mechanical engineer, including the electric- 

 al engineering branch, and matters assign- 

 able to civil engineering, distinctively, are 

 omitted ; it being assumed that the intei'- 

 ested engineer will find them in his ' Trau- 

 twine.' The aiithor of the new 'pocket- 

 book ' is a distinguished engineer and met- 

 allurgist, and has had a peculiarly fruitful 

 and fortunate variety of experience in those 

 departments. He supplemented a mercan- 

 tile education and some experience with a 

 course of study in mechanical engineering, 

 and subsequently had charge of iron and 

 steel works in Pittsburgh, edited a technic- 

 al journal, was the responsible laboratory 

 assistant in charge of important work of the 

 ' United States Iron and Steel Board,' and 

 has enjoyed a most unique and helpful ex- 

 perience as a consulting engineer. No one 

 could better comprehend precisely what is 

 demanded of the author of such a book. 



Throughout a period of now many years 

 material was in process of accumulation, as 

 advised by Nystrom : ' Every engineer 

 should make his own pocket-book.' The 

 construction of the book in hand was com- 

 menced at the request of the publishers, 

 who selected the presumably best prepared 

 man for the work, and the result of four 

 years of labor is an admirable, an extensive 

 and a ' meaty ' volume. 



The section devoted to the materials of 

 engineering, their strength and their prop- 



erties, is peculiarly valuable and complete. 

 It is a department in which the author is 

 thoroughly at home and with which he has 

 all his life been familiar. The revision of 

 the old formulse and their constants has been 

 very carefully and completely performed, 

 and this woi'k in itself constitutes a great 

 boon to the engineer. The wide range of 

 difference of proportions of parts of engines 

 and machines observed among contempo- 

 rary builders and ' authorities ' has been 

 the subject of long and conscientious labors. 

 When it is said that sizes of important 

 parts, in the best practice, for ' low-speed ' 

 and ' high-speed ' engines, respectively, av- 

 erage as four in the one to seven in the 

 other, and when it is known that variations 

 of ten to one, in certain proportions of parts, 

 among well-known makers, are known to 

 exist, the importance of this revision be- 

 comes appreciable. 



Experimental data are collated to date, 

 and in immense quantity in all depart- 

 ments, and the theory of construction, as 

 far as required and appropriate to such a 

 book as this, has been well condensed and 

 revised, not only by the author, but by 

 specialists whose aid has been sought by 

 him. 



The book is especially rich in matter re- 

 lating to the steam-engine and steam-boilers, 

 stationary, marine and locomotive, and a 

 moderate amount of space is well utilized 

 by a very condensed resume of principles 

 and practice in electrical engineering. It 

 may perhaps be fairly anticipated that this 

 section will grow somewhat with the raj)- 

 idly succeeding editions of the book which, 

 it is safe to predict, will follow. ReMger- 

 ating machinery here, for the first time, 

 finds space in some degree commensurate 

 with its growing importance, and theory 

 and practice are judiciously presented with 

 data derived by the best experiments yet 

 reported. 



This book has more importance, and de- 



