June 17, 1898.] 



SCIENCE. 



839 



Under the head of Physics of the Ether are 

 ■considered the constants of mirrors and lenses, 

 the combinations of these to form telescopes 

 and microscopes, the spectrometer and spectrum 

 analysis, magnetic and electric fields of force, 

 absolute measurements of electric current, 

 quantity, potential difference and resistance, 

 battery electromotive forces and resistances, 

 the use of galvanometers, the absolute determi- 

 nation of capacity and comparison of capacities, 

 «lectro-magnetic induction, eiiiciency curves for 

 incandescent lamps, thermo-electric power, and 

 radiation. 



On the assumption that such a course should 

 be progressive in diflficulty, the last parts re- 

 quire decidedly greater proficiency on the part 

 of the student. Many juniors will find it 

 necessary to read with special care the theoretic 

 discussion of capacity. In the exercise on 

 radiation Boys' radiomicrometer is employed 

 in place of thermopile and galvanometer. 



The book closes with a few tables of constants, 

 of natural functions and of logarithms. 



Upon the whole, this volume is a welcome 

 addition to the literature of the subject. Apart 

 from some obvious typographical errors, it may 

 be consulted with confidence in the accuracy 

 of its statements. While many other labora- 

 tories are less generously equipped than the 

 Ryerson physical laboratory, and therefore can- 

 not substitute this book for local instruction 

 ■cards, it contains so much of good suggestion 

 and is so well methodized that many instruc- 

 tors will surely utilize it in the improvement 

 of the instructions which they prepare for their 

 own students. 



W. Le Conte Stevens. 



SCIENTIFIC JOURNALS. 

 The American Naturalist for April, which has 

 just been received, opens with an article on the 

 Sarcostyles of the Plumularidse, by Professor C. 

 C. Nutting, followed by the third chapter of the 

 work on the wings of insects, by Professor J. 

 H. Comstock and Mr. J. G. Needham. The 

 present chapter treats of the specialization of 

 wings by reduction and is illustrated by twenty- 

 three cuts. There are briefer articles as follows: 

 ' A Case of Variation in the Number of Ambu- 

 lacral Systems of Arhacia punctulata, by H. L. 



Osborn ; ' Relationship of the Chriacidse to the 

 Primates,' by Charles Earle ; 'Further Notes 

 on Thermometer Crickets,' byC. A. Besseyand 

 E. A. Bessey ; ' Pollination of the Closed Gen- 

 tian by Bumblebees,' by E. J. Webb. 



Popular Astronomy for June opens with an 

 article on 'Scales of Seeing,' by Mr. A. E. Doug- 

 lass, of- the Lowell Observatory, in which he 

 discusses a standard scale which he hopes will 

 be generally adopted and used for comparison. 

 There are articles by Dr. Herman S. Davis on 

 women astronomers and Orrin C. Harmon on 

 the astronomy of Shakespeare, and short arti- 

 cles by Messrs. E. J. Wilczyuski, J. A. Park- 

 hurst and the editors. Professor W. W. Payne 

 and Mr. H. C. Wilson. 



A NEW journal of interest to students of agri- 

 cultural science, entitled Revue des Eyhrides 

 Franco- Americains, has been published since 

 January of this year by M. P. Gouy, Vals 

 pres Aubenas. 



SOCIETIES AND ACADEMIES. 



PHILOSOPHICAL SOCIETY OF WASHINGTON. 



The 486th meeting of the Philosophical So- 

 ciety was held at 8 p. m., May 28th, at the 

 Cosmos Club. Two biographical sketches were 

 read before the regular exercises for the even- 

 ing. The first was of Mr. C. H. Kiimmel by 

 Mr. Marcus Baker, the second of Mr. Orlando 

 M. Poe by Mr. O. H. Tittmann. The first sci- 

 entific paper was by Mr. Louis A. Fischer, who 

 described and illustrated in a general way the 

 methods for comparing ' line ' with ' end ' stand- 

 ards. He also described in detail a special 

 method for comparing such standards depend- 

 ing upon small auxiliary abutting pieces, the 

 principal features of which are that they are 

 very light and that the lines ruled upon them 

 are so close to abutting surfaces (about 0.8 mm.) 

 that the distance between the lines when the 

 pieces are in contact with one another may be 

 measured with the micrometer screw of any or- 

 dinary microscope. He called attention to the 

 fact that certain systematic errors amounting to 

 one part in 300,000 were discovered in the 

 lengths of bars determined by the Fizean, or re- 

 flection, method at the International Bureau of 

 Weights and Measures. This method was used 



