January 22, 1897.] 



SCIENCE. 



153 



I desired to state briefly the principal countries 

 •which were represented at Munich and not at 

 Paris, and vice versd, but I might add that, al- 

 though representatives from both Austria and 

 Russia came to Paris, yet there was much re- 

 gret at the absence of Prof. Hann, the eminent 

 director of the Austrian Meteorological Bureau, 

 and of Prof. Wild, late director of the Physical 

 Central Observatory at St. Petersburg, both of 

 whom had taken an active part in these inter- 

 national meetings since the first conference at 

 Leipzig in 1872. 



A. Lawrence Rotch. 

 Blue Hill Meteorological Observatory, Jan- 

 uary 6, 1897. 



THE STUDY OP FEAR. 



Editor of Science: One sentence in your 

 account of Prof. Stanley Hall's study of fear 

 has especially attracted my attention : ' ' The 

 fear of high places. President Hall thinks, is a 

 vestigial trace, like the gill slits under the skin 

 of our necks, antedating limbs and inherited 

 from our swimnling ancestors." A study of 

 fear by the comparative and genetic method 

 seems called for if results are to rest on a sure 

 and broad foundation. In my own investiga- 

 tions on the psychic development of animals 

 the subject has not been overlooked. I have 

 called attention to a peculiar manifestation 

 when even the youngest mammals and birds are 

 placed near the edge of a surface that is ele- 

 vated ; but I have also pointed out that a turtle 

 will walk off any such elevated support again 

 and again, and, as is well known, a frog will 

 jump almost anywhere, so that, if I understand 

 Dr. Hall aright in the above sentence, these 

 facts seem to present a difiBculty in the accept- 

 ance of this part of his theory. 



Wesley Mills. 



McGill University, Montreal. 



glossophaga teuei. 

 To THE Editor of Science : In the Proc. U. 

 S. National Museum, Vol. XVII., No. 1100, 1 de- 

 scribed a new species of bat under the name Glos- 

 sophaga villosa. But a Glossophaga villosa was 

 described by Rengger (Naturgesch. der Siiugeth. 

 von Paraguay 1830, 80). I, therefore, rename 

 the new species. I propose the following : 

 Glossophaga truei, after Mr. Frederick W. True, 



the accomplished curator of Mammals at the 

 Museum. Harrison Allen. 



Philadelphia, Pa., January 13, 1897. 



SCIENTIFIC LITERATURE. 

 Elude de Huit Essais de Machine & Vapeur. Par 



V. Dwelshauvers-Dery. Extrait de la 



Revue Universelle des Mines, t. xxxvi., 1896. 



Mon. Dwelshauvers-Dery has published re- 

 cently a report on the work of his laboratory, 

 on his experimental engine, relative to the effi- 

 ciency of the machine under various conditions, 

 mainly affecting the quality of steam supplied.* 

 He supplements that report, in the article here 

 referred to, by a more complete study of these 

 effects, and with extended illustration of his 

 methods of conducting the work and of giving 

 instruction in this department. He describes 

 the conduct and computation of eight engine- 

 trials, four with saturated and four with super- 

 heated steam. His conclusions from the pre- 

 liminary study have already been given. f 



Dwelshauvers is a consistent follower of 

 Hirn, whose ' practical ' or applied theory of 

 the steam-engine he has developed, giving it 

 algebraic expression and establishing seven 

 principal equations by means of which he is en- 

 abled to compute essential data from the re- 

 sults of observation during an engine-trial. 

 These expressions and their derivation are 

 given in the report here under review. His 

 graphical illustrations of the method of distribu- 

 tion and of variation of thermal and of dynamic 

 energies in the cycle studied, and their inter- 

 conversion, afford a means of bringing clearly 

 before the investigator and the student the es- 

 sential facts of engine-operation, in each case, 

 and throw into high relief the most important 

 phenomena. 



They show clearly how great is the quantity 

 of heat-energy exchanged between steam and 

 cylinder-wall, and bring out plainly the fact 

 that this waste is enormously less with super- 

 heated than with saturated steam. They show 

 that the use of the steam-jacket is ' but a pal- 

 liative, not a radical and complete remedy ' for 

 this waste. The steam-jacket, while almost 

 invariably reducing wastes, nevertheless itself" 

 * Revue Universelle des Mines, t. xxsiv., 1896. 

 t Science, N. S., Vol. IV., No. 89, p. 654. 



