366 Scientific Intelligence. 



2435-159, 2506-904, and 2528*516. The spark data exceed these 

 numbers by 0*053, 0*151, and 0*069 A respectively. Whether 

 these differences are due to the manner of excitation (arc versus 

 spark) of the radiations or to instrumental errors is a question 

 which needs further consideration. — Proc. Roy. Soc, vol. xc (a), 

 p. 512. h. s. u. 



8. Solar Oxygen. — Attention has already been called to the 

 investigation of Runge and Paschen which showed that a cer- 

 tain triplet in the spectrum of the iron arc in air is due to oxygen. 

 (See vol. xxxvii, page 195.) This triplet at about A 7V74 and the 

 doublet at X 8446 match lines in the solar spectrum and hence 

 they may be either of solar or of telluric origin. From con- 

 siderations of intensity Jewell concluded that the triplet is caused 

 by solar absorption but he was unable to detect the Doppler 

 effect. At the suggestion of Paschen the problem was taken up 

 hj K. W. Meissner. By using a plane-grating spectrograph of 

 high resolving power in conjunction with plates specially sensi- 

 tized with dicyanin it was possible to record photographically, 

 and to determine the magnitude of, the Doppler displacement of 

 the lines in question from the opposite limbs of the sun. There 

 remains, therefore, no doubt concerning the evidence that oxygen 

 is present in the solar atmosphere. — Phys. Zeitschr., July 1, 1914, 

 p. 668. h. s. u. 



9. X-Rays ; G. W. C. Kaye. Pp. xx, 252, with 97 figures. 

 London, 1914 (Longmans, Green and Co.). — This book covers 

 the ground very well from the time of Rontgen's discovery in 

 1895 down to the end of the year 1913. u The author trusts that 

 the form of the book will be acceptable, not only to the student 

 of physics, but to the man of general scientific interests, and 

 particularly to the members of the medical profession, . . . 



. ." Consequently the treatment is non-mathematical. The 

 successive chapters deal respectively with : — the phenomena of 

 a discharge tube, cathode rays, positive rays, X-rays, an X-ray 

 bulb, high-potential generators, the " hardness " of an X-ray bulb, 

 the blackening of an X-ray bulb, the measurement of X-rays, 

 secondary rays, further properties of the X-rays, practical 

 applications of X-rays, interference and reflection of X-rays, and 

 the nature of the X-rays. The practical value of the text is 

 increased by the inclusion of five appendices, twenty-eight 

 tables and an index. The material is presented in a very clear 

 and pleasing style, the number of errors is small, and the reading 

 of the volume leaves one with the impression of time well and 

 profitably spent. h. s. u. 



10. A First Rook of Experimental Science; arranged by 

 W. A. Whittox. Pp. vii, 13V, with 77 figures. London, 1913 

 (Macmillan and Co.). — " The scope of this book has been deter- 

 mined largely by the syllabus prescribed by the Civil Service 

 Commissioners for Boy Artificers who wish to enter the Royal 

 Navy as Engineroom Artificers." The experiments suggested 

 pertain to statics, hydrostatics, heat, combustion, and the elemen- 



