Supplement to ''Nature" March 5, 1908 



tnann covers biology as well. One half of the work 

 is taken up with detailed recommendations for class 

 teaching in branches of natural science, viz. physics, 

 chemistry, mineralogy, geology, astronomy, and 

 biologv, then chapters are added on the equipment 

 of laboratories, the preparation and use of text-books, 

 the training of science teachers, the treatment of 

 scientific ideas in the order of their historical develop- 

 ment ; then some half-dozen appendices give docu- 

 ments taken partly from the regulations of the 

 "Cultus Ministerium in Prussia and in other German 

 States, side by side with resolutions adopted by asso- 

 ciations of science teachers, in which no doubt Dr. 

 Dannemann is a leading personality. 



The adoption of the term" praktisch-heuristisch " is 

 sufficiently significant of the author's position. He 

 ■does not give the history of the name " heuristic," 

 ;md onlv incidentally refers to Prof. Armstrong, but 

 in all his work he is definitely on the side of those 

 who insist that the centre of a course of science teach- 

 ing shall be at the bench in the laboratory, and that 

 demonstration and discussion in the class-room must 

 be associated with and take their cue from this 

 centre of activity. He has nothing but scorn for the 

 " Kreidephysik " which is still too commonly found in 

 German schools, where the teacher with his chalk 

 and blackboard demonstrates the truths of natural 

 jihilosoph}-. It is very interesting to witness, from 

 the pages of this work, how very leluctant German 

 luthorities are to adopt these reforms, and no doubt 

 a strenuous advocate of English methods has not 

 nhvavs a happy time among his countrymen. Indeed, 

 the case is curiously paralleled by what is happening 

 in England as regards modern language teaching. 

 The " reformers " here look chiefly lo Vietor and 

 others in Germany for inspiration, and turn to many 

 examples in German schools to show how a foreign 

 language can be acquired. Dr. Dannemann tells his 

 countrvmen to look to the practical English teacher 

 and to abandon their reliance on the parrot-like learn- 

 ing of scientific text-books. 



.\lthough much of the ground covered by these 

 chapters will be familiar to the English teacher of 

 science, there arc portions which are novel, espe- 

 <iially in the plans by which the author hopes to give 

 a secondarv schoolboy some grasp of the entire field 

 of natural science before leavmg school; and the 

 sketch of science teaching from the genetic standpoint 

 is also well worthy of careful perusal. 



The chapter on the training of science teachers 

 seems to us the weakest part of the book. It is 

 difficult to see how university men can be kept for a 

 vear doing the very elementary work which Dr. 

 Dannemann proposes for therh ; a man ought to have 

 learned, during his university career in laboratories, 

 to be able to secure himself and his scholars against 

 accidents. But it is a little difficult to realise fully 

 the conditions of German schools in these respects. 

 A\'e are sure from the quality of this and other writ- 

 ings by the author that any "Kandidat " who was sent 

 to learn the business of a science teacher from him 

 would gain a thorough understanding both of prin- 

 ciples and practice. 



NO. 2001, VOL. 77] 



W'lKELESS TELEGRAPHY AND TELEPHONY. 

 Ja'nrbiich der drahtlosen Telegraphic tiiid Telephonic. 

 Band i.. Heft i. Edited by Dr. G. Eichorn. (Leip- 

 zig : S. Hirzel, 1907.) Preis fur den Band, 20 marks. 



Wireless Telephony in Theory and Practice. By 

 E. Ruhmcr. Translated by J. Erskine-Murray. 

 Pp. XV -I- 224. (London : Crosby Lockwood and 

 Son, 1908.) Price io.<. bd. net. 



THE publication of the first number of a German 

 year-book of wireless telegraphy and telephony 

 affords an indication of the growing importance of 

 this branch of electrotechnics. The volume before us 

 is more of the character of an ordinary scientific maga- 

 zine than of a year-book, since there is not really 

 much attempt to summarise the progress during the 

 past year, which, ve take it, is peculiarly the function 

 of a vear-book. This objection apart, the publication 

 deserves praise on account of the merit of the articles 

 which it contains. Of these the most important are 

 one by Prof. F. Braun on directed wireless telegraphy, 

 one by Dr. Simon on the production of undamped 

 waves, and one by Prof. Fleming on some of the most 

 recent developments. 



Dr. Simon's article will be read with special in- 

 terest at the present time on account of the experi- 

 mental work which is being carried on in all countries 

 for the development of wireless telephony. In addi- 

 tion to these and some minor papers, there is a 

 valuable bibliography. 



The development of wireless telegraphy during the 

 twenty years which have passed since the discoveries 

 of Hertz has presented some peculiar features. Grown 

 out of a discovery which, theoretically regarded, was 

 of a sensational nature, wireless telegraphy has always 

 seemed to have a tendency to sensational rather than 

 solid progress. Except in so far as its military and 

 naval value is concerned, the world at large cannot be 

 said to have derived as yet any very great advantage 

 from its development, and we doubt whether financial 

 success, the touchstone of utility, has as yet rewarded 

 any of the companies which have been pioneering the 

 various systems. On the other hand, sensational per- 

 formances, in which the hearts of all wireless workers 

 appear to rejoice, have been frequent. The Marconi 

 Company's first attempts to establish Transatlantic 

 communication, the signal failure of their first com- 

 mercial system of Transatlantic wireless telegraphy, 

 and the apparent failure, so far, of their more recent 

 attempt, will be fresh in the minds of all. As we have 

 before pointed out in these columns, it would appear 

 that the enormous efforts and expenditure which have 

 been lavished on the development of long-distance 

 signalling might have been much more usefully spent 

 on the dei-elopment of less ambitious but more solidly 

 useful schemes. 



More recently the attention to the production of 

 undamped oscillations on the principle of the Duddell 

 musical arc (as in the Poulsen system) has stimulated 

 research on the wireless transmission of speech, and 

 considerable success has attended the experiments. In 

 Germany successful transmission across ten miles of 

 land (right across Berlin) has been attained, and in 

 America, in addition to the equipment of the torpedo- 



