352 SCIENCE PROGRESS 



might at least be introduced, and the word "elementary" substituted for "general" 

 in the title of the first chapter. But why not put the complete theory wholly into 

 an Appendix, and start with the present Chapter II — " Action and Working of the 

 Diesel Engine " ? 



Taking another important section, " Valves and Cams," we find the subject- 

 matter wholly descriptive. It is as if an author on " Mechanics " was content to 

 dismiss the common or garden pump with — 



H is the handle, 



S is the spout, 



You heave up the handle, 



And the water comes out. 



It cannot be disputed that an engineer without a previous knowledge of the 

 Diesel engine will have some idea of " Valves and Cams," but what will be the 

 value, the depth, of his knowledge ? Exactly on a par with the student's know- 

 ledge of the pump as described above. 



As a record of the design and construction of the Diesel engine as it stood in 

 191 5 the work is of distinct merit, and the many fine drawings will be of great 

 value to designers and constructors alike. It is the very merit in this direction 

 that makes the opening chapter grotesque. 



J. Wemyss Anderson. 



GENERAL 



The Dramas and Dramatic Dances of Non-European Races in Special 

 Reference to the Origin of Greek Tragedy, with an Appendix on the 

 Origin of Greek Comedy. By William Ridgeway, Sc.D., F.B.A. 

 [Pp. xv + 448, with 92 illustrations.] (Cambridge : at the University 

 Press, 191 5. Price 15s. net.) 



It will be remembered that three or four years ago Prof. Ridgeway published a 

 book on The Origin of Tragedy, in which he advanced the theory that Tragedy 

 originated not in the worship of Dionysus, as had been hitherto supposed, but in 

 the rites in honour of deceased " heroes." This new theory was subjected at the 

 time to severe criticism by scholars who adhered to the older opinion. The 

 present work is Prof. Ridgway's reply to his critics, being in fact, as he explains, 

 an expansion of a short chapter in The Origin of Tragedy, in which he had briefly 

 given " some evidence from the dramatic performances of Asiatic countries in 

 support of his doctrine of the origin of Greek Tragedy." The body of the work 

 is preceded by an introduction, defending his view and taking the offensive against 

 the theory, started by Mannhardt half a century ago and made familiar to British 

 readers by The Golden Bough, attributing the periodic celebrations in Europe and 

 elsewhere to the observances of the agricultural seasons, the worship of trees, 

 and of a more generalised " Vegetation-Daemon." After this preliminary recon- 

 naissance in force, the distinguished author begins his serious attack by a lengthy 

 but interesting account of the Passion Play of Hassan and Hussein, still performed 

 by the Shiah Mohammedans of Persia and India. He goes on to argue that 

 Adonis, Attis, and Osiris had, before entering on godhead, been as real human 

 beings as Muhammad, Ali, Fatima, Hassan and Hussein, and that the quasi- 

 dramatic representations periodically given in their honour were performances 

 having reference to the adventures and sorrows of their earthly life. He turns to 

 India and argues in like manner concerning Rama and Krishna, describing the Hindu 

 drama and elaborately discussing its origin and development. After dealing with 



