January 10, 1902.] 



SCIENCE. 



65 



(1) The results confirm those of Sehultze 

 that isolated pieces from the center of the 

 heart can contract in sea water. (2) They 

 have established the new facts, (a) that 

 in the intact animal the heart may some- 

 times beat from the center toicards both 

 ends; also, (&) that when the heart is tied 

 near the center, the isolated pieces may 

 sometimes beat from the center towards the 

 ends; and (c) in such pieces there may 

 even be a regular alteration in the direc- 

 tion of the heart-beat. These last results 

 will probably necessitate a complete change 

 in our conception of the character of the 

 Ascidian heart-beat. 



This is a proper place to record the oc- 

 currence of Branchiostoma Californiense 

 at San Pedro, hitherto not known farther 

 north than San Diego. About a dozen 

 specimens were dredged during the sum- 

 mer, some in the inner harbor, and others 

 outside but near its mouth. 



It may also be noted here that the Point 

 Loma blind fish, Typhlogobius Calif ornien- 

 sis, hitherto not reported north of San 

 Diego, was found at San Pedro. At 

 White's Point it was found in holes in the 

 soft rock and under stones; while during 

 the Peridinium visitation a considerable 

 number of specimens were cast ashore, 

 some alive and others dead, along the 

 breakwater at San Pedro. 



Wm. E. Ritter. 



Univebsitt of Califoenia, 

 Bekkeley, October 29, 1901. 



SCIENTIFIC BOOKS. 

 A Treatise on Hydraulics. By Henry T. 

 BovEY, M. Inst. C.E., LL.D., F.R.S.C. Sec- 

 ond edition, rewritten. New York, John 

 Wiley and Sons. 1901. Pp. xviii + 683. 

 Figs. 330. Price, $5.00. 

 The second edition of Dr. Bovey^s well- 

 laiown text-book is practically a new work, 

 having been largely rewritten, rearranged and 

 nearly doubled in extent; forming a very im- 

 portant and valuable addition to the literature 



of engineering education. It contains 583 

 pages and 330 figures, as against 337 and 196, 

 respectively, in the first edition; embodying 

 also some improvements in mechanical execu- 

 tion, such as the substitution of clear-cut line 

 engravings for the few (but hazy) half-tones 

 illustrating certain water-meters in the first 

 edition, and the use of bold-faced tj^e for im- 

 portant formulae. Being printed on thinner 

 paper the present volume possesses no more 

 weight or bulk than the earlier book. 



As in the earlier edition, the statements of 

 mauy numerical examples, with their answers, 

 are placed at the end of each chapter, and 

 these have been greatly increased in number 

 (e. fir., at the end of Chapter I. we find 106 ex- 

 amples as against 76 in the first edition) ; but 

 a new and special feature in this respect con- 

 sists in the insertion, in the body of the text 

 in connection with each topic, of numerical 

 examples fully worked out in all their details. 

 This added feature will be heartily welcomed 

 by engineering students possessing only aver- 

 age mathematical ability, and hence needing 

 careful guidance in the principles of correct 

 numerical substitution. 



Among additions to the subject-matter the 

 following are prominent : 



A description of the elaborate apparatus in 

 the Hydraulic Laboratory of McGill Univer- 

 sity, for experimentation with jets of water 

 (as to coefficients of eflux, form of jets and 

 impact of jets on vanes and cups of various 

 shapes) ; with methods of use and results ob- 

 tained. 



An illustrated abstract (ten pages of fine 

 Ijrint) of Bazin's papers in the Annales des 

 Pants et Chaussees on experiments with 

 weirs; including the phenomena of depressed, 

 drowned and adhering nappes. 



In connection with flow in pipes, the for- 

 mute of Darcy, Hagen, Thrupp, Reynolds, 

 Levy, Vallot, Manning, Tutton, Flamant, 

 Foss and Lampe. 



Many of the results obtained by Mr. C. H. 

 Tutton in 1896 in his careful and extended 

 collation, and logarithmic plotting, of the ele- 

 ments of some 1,000 recorded experiments on 

 the flow of water in pipes ; with diagrams and 

 formulse. 



