444 



SCIENCE. 



[N. S. Vol. XII. No. 299. 



Several facts are added to our knowledge of 

 the minor anatomy of the oyster, especially in- 

 teresting being the demonstrated change in the 

 primitive retractor pedis muscle whereby it be- 

 comes a dilator oris. 



The paper is well illustrated. 



H. F. Moore. 



"Washington", August 25, 1900. 



Anatomie el physiologic veg&tale. For the use 

 of students of natural science in universities 

 and agricultural schools, etc. By Professor 

 Er. Belzung. Ancienne Librairie, Germer 

 Baillifere et Cie. Paris, 1900. 1699 Figs. 8vo. 

 Pp. iii + 1320. 



Professor Belzung is the author of text-books 

 on geology, zoology, animal physiology, and ani- 

 mal paleontology, in addition to two or three bo- 

 tanical works besides the subject of this review. 

 Such breadth of authorship undoubtedly relieves 

 him from any taint of narrow specialism. This 

 experience secures for the book in question, 

 however, no new points of view, since it is a 

 purely formal presentation of the better known 

 facts in botany compiled after the manner of an 

 encyclopedia. Perhaps the freshest portion of 

 the book is that taken up with the subject of 

 fermentation, which is given a treatment not 

 usually accorded this phase of botany in general 

 texts. The final section of the work consists of 

 the ' Conclusions ' and is devoted to the general 

 characters of protoplasm and plants usually 

 given in the introductory chapters of such 

 texts. 



The book leads chiefly to the examination 

 room, and only the most determined enthusi- 

 asm could carry through its use a genuine in- 

 terest in the study of plants. 



D. T. MacDougal. 



Report of Competitive Tests of Street Car Brakes. 

 By the Board of Railroad Commissioners 

 OP THE State of New York. 1899. Al- 

 bany, Brandon Printing Co., Department 

 Printer, 1900. 8vo. Pp. 60 ; 67 sheets of 

 diagrams. 



The report of the electrical expert, Mr. C. R. 

 Barnes, April 4, 1900, details the origin and 

 progress of the work of the N. Y. State Board 

 of R. R. Commissioners, conducted to ascertain 



the practicability of insuring greater safety in 

 the operation of street cars moved by cable and 

 by the electric current, comparing the newer 

 forms of brake with the older. It is stated that 

 295 people have been killed and 1599 injured 

 by the electric railways of the State of New 

 York in three years, as shown by the records 

 of the Board. These figures indicate a rapid in- 

 crease in this form of mortality, due to rising 

 weights of cars and increasing speeds. Cars 

 are now in use weighing 23 tons and speeds ex- 

 ceeding 50 miles an hour have been attained on 

 suburban lines. 



In preparing for these trials Messrs. Barnes 

 and Pierson, the electrical engineer of the 

 Metropolitan R'y Co., designed and constructed 

 an automatic recording apparatus for measuring 

 lengths of run under action of the brake. The 

 apparatus was calibrated on 275 feet of track 

 assigned for the purpose by the railway com- 

 pany and the essential observations and data 

 were derived by use of this instrument ; the 

 work being performed in New York on the 

 Lenox Avenue line, in the half-mile between 

 135th and 146th streets. Sixteen brakes — 4 

 air-brakes, 4 electric, 3 hand-power, 2 friction 

 and 2 ' track-and-wheel ' brakes — were tried. 



The reliability of the air-brake is reported 

 to be thoroughly established and a number of 

 them have come into use. But one electric 

 brake, that of the General Electric Co., is in 

 use to any extent. New forms of the older 

 type, the hand-power brake, were tested. They 

 act directly upon the wheels, as usual. The 

 so-called ' friction-brake ' is a friction device 

 on the axle, usually disks rotating with the 

 axle and engaging stationary disks, the two 

 sets arranged to be forced strongly against each 

 other, when in action, by means of ingenious 

 mechanisms. The ' track-and-wheel brake ' 

 acts on the tracks'as well as the wheel. Photo- 

 graphic reproductions of the autographic dia- 

 grams obtained from each brake are published, 

 with appended tables exhibiting results numer- 

 ically. 



The usual experiences in such work with dil- 

 atory exhibitors, incomplete outfits and occa- 

 sional miscarriage of the plans of the Board 

 was observed in these trials ; but a large 

 amount of new data in a novel field of re- 



