428 



SCIENCE. 



[N. S. Vol. VII. No. 169. 



paper of Professor J. Willard Gibbs, on ' Graph- 

 ical Methods in Thermodynamics,' in the 

 Transactions of the Connecticut Academy of 

 Sciences, 1873, the ' entrophy-temperature dia- 

 gram ' has attracted little attention until within 

 a comparatively few years. Brought out by 

 that writer twenty-five years ago, it was left 

 unnoticed for a long time, and it was only 

 when, recently, the eminent and able mathe- 

 matical physicist and engineer, Mr. J. Mac- 

 Farlane Grey, employed it in his papers, 

 read before the British Institution of Naval 

 Architects, and later. Professor Cotterill took 

 it up, and the late Mr. Willans gave it practi- 

 cal application in the exposition of the experi- 

 mental work on his engines which gave him 

 fame, that it has been thought worth while, on 

 the part of engineers, to make use of what 

 proves to be a very beautiful method of exhibit- 

 ing heat-exchanges and transformations in 

 heat-engine cycles, and especially with the 

 steam-engine. 



The recent publication of Professor Ewing 

 on the steam-engine, in which this system is 

 employed to some extent, has called attention 

 to the subject once more, and the indications 

 would seem to be that the entropy-temperature 

 diagram will now find frequent use in the 

 hands of the engineer in the exposition of ther- 

 modynamic problems. 



The particular form given this diagram, in 

 order to make it available for general use, in 

 this publication by Professor Reeve, is that 

 adopted by Professor Boulvin, of Ghent Univer- 

 sity, modified by the present author to meet the 

 demands of the profession in a more complete 

 and satisfactory manner. It exhibits the four 

 quadrants, devoted in the present case to en- 

 tropy-volume changes of steam, to volume-pres- 

 sure, to temperature-pressure and to entropy- 

 temperature variations, taking the series clock- 

 wise, and exhibiting the various curves drawn 

 to a moderately large scale. There are also 

 printed upon the sheet the proper tables and 

 blanks for use in tabulating data of steam- 

 engine trials. Accompanying is a text, de- 

 scriptive of the diagram and its uses, indicat- 

 ing the character of its lines and the methods 

 of analysis appropriate to the purposes of the 

 engineer. 



The text is concise and clear and the plate 

 well made. It would be an improvement were 

 the latter given a light and strong cloth 

 backing, and were a pocket supplied in the 

 cover of its text, in which to preserve it. The 

 cost would be slightly increased, but the sheet 

 would be thus rendered comparatively safe. 

 With care in mounting, and iuspeotion after- 

 ward, the diagram could probably be thus 

 guarded without measurable distortion. 



The diagram should find many users and 

 prove of real assistance to many investigators 

 and illustrators of thermodyamic problems. 

 R. H. Thurston. 



Cornell Univeesity . 



SOCIETIES AND ACADEMIES'. 

 ANTHROPOLOGICAL SOCIETY, WASHINGTON. 



The 274th regular meeting of the Anthropo- 

 logical Society was held Tuesday, March 1, 1897. 



Dr. J. Walter Fewkes read a paper on ' The 

 Altar of the Great Snake of Walpi,' which he 

 described in detail, and stated it to be dilferent 

 from those of the Snake Dance proper. 



A number of illustrations, colored charts and 

 drawings were used to show the structure and 

 construction of the altar. 



In his paper on ' Snake Worship among the 

 Navaho,' Dr. Matthews stated that the Navahoes 

 have ophiolatrous rites ; but they do not handle 

 or introduce live snakes after the manner of the 

 Moki. While their rites do not seem to be derived 

 directly from those of the Moki both have much 

 in common and are probably borrowed from 

 a common source ; still they differ in many im- 

 portant respects. The ceremonial circuits are 

 different. A Navaho will not kill a snake ; if 

 he finds one coiled in his path he will lift it 

 gently with a stick and throw it to one side. 

 They think the serpent possessed of extraordi- 

 nary wisdom ; that it understands human lan- 

 guage and may make evil use of human knowl- 

 edge ; hence their most sacred rites may be 

 performed and their myths may be told only 

 in winter, when the snakes are hibernating. A 

 picture was shown which was a copy of a 

 Navaho dry-painting or sand-altar. It might 

 be considered a Navaho snake-altar. It repre- 

 sented the home of the Navaho snake-god ; a 

 minute description of it was given. 



