346 



SCIENCE. 



[N. S. Vol. XI. No. 270. 



The style of the book is on the whole simple 

 and clear (what does the subject-matter admit 

 of else?), but one is occasionally startled by 

 such English as this (p. 38) : " In birds, at about 

 the middle, the mid-gut bears a blind tube," 

 or as this (p. 223) : "The lampreys feed upon 

 the mucus and blood which they rasp from 

 fishes." 



The method of treatment is then strictly 

 morphological — the first part dealing with the 

 morphology of the organs — the second part 

 adding to this so much of external morphology 

 as is of use in classification. Judged as a mor- 

 phology the book deserves to be commended. 

 But does this warrant the author in calling it a 

 zoology ? 



A categorical description of the structures of 

 vertebrates so arranged as to suggest their evo- 

 lution is but a part of zoology. In the opinion 

 of the reviewer it is the least interesting part, 

 and by many modern workers It is regarded 

 as the J east important. It would be hard to 

 imagine a college student calling Professor 

 Kingsley's book either interesting or stimula- 

 ting, though if used as directed in connec- 

 tion with lectures and laboratory work he will 

 surely find it of value. It is easier to point out 

 faults than to show how they may be remedied, 

 but why, may we ask, should three pages 

 be given to the mouth, lips, teeth and tongue, 

 and no word said of the chain of causal rela- 

 tions connecting lip development in mammals 

 with the power of mastication, heterodont 

 dentition and articulate speech, so admirably 

 worked up by Gegenbaur ? Why an account 

 of the peculiarities of structure of the Eaise 

 and no word as to the relation of these pecu- 

 liarities to the mode of life? And so the rest 

 of it : if we are to have pure morphology, why 

 not more of the spirit of Gegenbaur and less 

 of that of Haeckel? When the ideal text-book 

 of zoology is written it will surely deal with 

 causes, not merely with results. 



Jacob Reighaed. 



Univeesity of Michigan. 



Water-Supply Engineering : The Designing, Con- 

 struction and Maintenance of Water-Supply 

 Systems, both City and Irrigation. By A. 

 Pkbscott Folwell, Associate Professor of 



Municipal Engineering in Lafayette College. 



First Edition. New York, John Wiley and 



Sous. 1900. Octavo, 562 pages and 19 



plates. Price, $4.00. 

 The Filtration of Public Water-Supplies. By 



Allen Hazen. Third Edition, Revised and 



Enlarged. New York, John Wiley and 



Sons. 1900. Octavo, 321 pages and 22 



plates. Price, $3.00. 



It is a happy feature of American engineer- 

 ing education that many of the text-books used 

 by the student are also manuals constantly con- 

 sulted by the engineer in making his designs. 

 In such a system of education there is no con- 

 flict between theory and practice, but each 

 supplements and improves the other. Theory 

 is indeed merely the systematic formulation 

 of general laws derived from experience, and 

 practice is the application of theory to the 

 economic production of useful results. Both 

 of the above books are well adapted to class 

 use, both exhibit the details of the latest 

 theories and constructions, and both are of 

 high value to the practicing engineer. The 

 first book covers the wide field of all the fea- 

 tures of water works, while the second treats 

 of that special part concerned with the im- 

 provement of the quality of the water. 



Professor Folwell has succeeded well in pre- 

 senting the principles and practice of this wide 

 field in a single volume. The theoretical dis- 

 cussions may sometimes be criticised as rather 

 incomplete, but it is evidently intended that 

 the reader should have a good knowledge of 

 applied mechanics and hydraulics. The ques- 

 tion of the force of impact caused by a moving 

 body or stream of water, which is always puz- 

 zling to practical men, especially needs correc- 

 tion and revision on pages 229 and 247. On 

 the whole, however, the theory seems as well 

 presented as can be done in such limited space. 

 The practical details relate largely to the water 

 supplies of cities and towns, irrigation systems 

 being properly given a subordinate place. The 

 subject of designing which includes quantity 

 and quality of water and the details of the 

 systems of collection, purification, and distribu- 

 tion, covers 452 pages, while construction and 

 operation are treated in 94 pages. Methods of " 

 cleaning water mains, of thawing out frozen 



