46o 



INDEX. 



Smell, 290-292 



Soap films, 8-10 



Solar radiation, 354, 367, 389 

 Forbes's estimate of, 389 

 Langley's estimate of, 389 

 Pouillet's estimate of, 367, 



389 

 Sorting demon, Clerk-Maxwell 's, 



137-141, 225, 226 

 Sound, 204-281 



propagation of, 301-311 

 speeds of vibrations in, 278- 



281, 305-309, 313, 314 

 wave-length of, 307-309 

 Specific heat, 355, 356 note 

 Spectrum, 321-325 

 Stokes, 204-213, 283 

 Sun, convection currents in the, 



385, 398 

 density of the, 388, 389, 



398-401 

 early history (nebular) of the, 



403-415 



effect of gravitational con- 

 densation of the, 356-359, 



365, 366, 372, 373, 384- 

 388, 390, 39i 



mechanical analogue of the, 



375-384 

 present temperature of the, 



361 363, 401-403 

 probable antecedents of the, 



415-422 

 secular cooling of the, 351- 



361 



specific heat of the, 359-361 

 thermal capacity of the, 387 

 Sun's heat, the, 349-422 

 age of the, 349-368 

 meteoric theory of the, 364- 



366, 372 



origin and amount of the, 

 363-368 



Surface-tension, 16, 30, 32, 49- 



55 



TASTE, 290-^92 



"Tears of strong wine," 50-52, 



56-59 

 Thomson, Prof. James 50, 56- 



59 



UNITS, C. G. S., 95, 103, 104- 



120 



reproduction of, 104-120 

 Q. G. S., 120-123 

 Unit of length, 104-110, 153 

 of mass and force, universal 



gravitation, 92, 95-103 

 of time, no- 1 20 

 Uranium glass, 207-213, 282, 283 



"v" (ratio of electrostatic to 

 electromagnetic unit of reck- 

 oning), 83, 111-113, 11 9> I2O > 

 133, 441-443 



Vortex motion, 239-252 



WAVE-LENGTH, model showing 



a, 155-158 



diagrams showing, 187-190 

 of light, 312, 313, 319, 324, 



325, 335-342 

 of sound, 307-309 

 Weber, 81-83, 431-433 

 Wilson, Dr. George, on the 



senses, 254 



Work done, by capillary attrac- 

 tion, 10-16 



by capillary attraction in 

 relation to surface ten- 

 sions, 20 

 by change of shape, 17, 1 8 



ZODIACAL light, 352 



RICHARD CLAY AND SONS, LIMITED, LONDON AND LUNGAY. 



