INDEX. 



471 



prime azimuth for the different 

 Fraunhofer's lines, 321. 

 Rayleigh (Lord) on the manufacture 

 and theory of diffraction-gratings, 

 81, 193 ; on the theory of resona- 

 tors, 419. 

 Reflection and refraction, on the 

 boundary-conditions of, for the 

 principal section of media in mo- 

 tion, 411. 

 Refraction, on double, in a viscous 



fluid in motion, 390. 

 Resonators, on the theory of, 419. 

 Reynolds (Prof. O.) on the conden- 

 sation of a mixture of air and steam 

 on cold surfaces, 67. 

 Roberts (S.) on a simple condensing 

 collector for frictional electrical ma- 

 chines, 49. 

 Roberts (W. C.) on the quantitative 

 analysis of certain alloys by means 

 of the spectroscope, 311. 

 Rosse (the Earl of) on the electric 



resistance of selenium, 161. 

 Roval Institution, proceedings of the, 



374. 

 Royal Society, proceedings of the, 61, 



216,309,384,447. 

 Sale (Lieut.) on the action of light on 

 the electrical resistance of selenium, 

 216. 

 Sarasin (E.) on the effects of mag- 

 netism on the electric discharge 

 through a rarefied gas, 462. 

 Secchi (Father A.) on the tempera- 

 ture of the sun, 394. 

 Selenium, on the electric resistance 

 of, 161 ; on the action of light on 

 the electrical resistance of, 216. 

 Serrano y Fatigati (H.) on the me- 

 chanical equivalent of heat, 155. 

 Sharp (S.) on the oolites of North- 

 amptonshire, 74. 

 Siemens mercury unit of electrical 

 resistance, on the absolute value 

 of, 294, 342. 

 Silicic acid, on a peculiar occurrence 



of crystallized, 319. 

 Sky, measurements of the polarization 



of the light reflected by the, 127. 

 Soret (J. L.) on some phenomena of 

 polarization by diffusion of light, 

 205. 

 Sound, on the effects produced by 

 fog and vapour in the atmosphere 

 on the intensity of, 277, 3/4. 



Sounding pipe, on a process for veri- 

 fying the nodes in a, 80. 

 Spectroscope, on the quantitative 

 analysis of certain alloys by means 

 of the, 311. 

 Spectrum-analysis, researches in, 



384. 

 Steam, on the condensation of a mix- 

 ture of, and air on cold surfaces, 

 67. 

 Steel, on the permanent magnetism 



of, 315. 

 Stefan (J.) on the theory of the mag- 

 netic forces, 381 ; on apparent ad- 

 hesion, 465. 

 Sterlingite, on the crystallographic 

 structure and chemical composition 

 of, 247. 

 Stewart (Prof. B.) on the heating of 

 a disk by rapid rotation in vacuo, 

 219. 

 Sun, on the spectrum of the, 384 ; on 



the temperature of the, 394. 

 Sundell (Dr. A. F.) on the electro- 

 motive and thermoelectric forces of 

 some metallic alloys in contact 

 with copper, 28. 

 Sun-spots, on the period of hemi- 

 spherical excess of, 311. 

 Tait (Prof. P. G.) on the heating of 

 a disk by rapid rotation in vacuo, 

 219. 

 Telegraph-lines, on the testing of, 22, 



93, 416, 426. 

 Terquem (A.) on the vibroscope tono- 

 meter, 212. 

 Thomson (Prof. J.) on certain rela- 

 tions between the gaseous, the 

 liquid, and the solid states of 

 water-substance, 447. 

 Tonometer, on the transformation of 



the vibroscope into a, 212. 

 Tribe (A.) on an air-battery, 61.' 

 Troost (L.) on hydrogenized palla- 

 dium, 397. 

 Tyndall(Prof) on the acoustic trans- 

 parency and opacity of the atmo- 

 sphere, 374. 

 Vapour, on the effects produced by, 

 on the intensity of sound, 27/, 

 374. 

 Vermicuiites, on the, their crystallo- 

 graphic and chemical relations to 

 the micas, 241. 

 Vibrations, on the determination of 

 the absolute number of, 212. 



