INDEX. 



517 



STATIC. 



positions furnishing historical data, 

 88, 89 ; made visible by refraction, 

 1 54 ; peculiar law of light demon- 

 strated by the aberration of, 202 ; 

 magnitude of the solar system seen 

 from, 226 ; numbers, classification 

 of, 384 ; positions, 385 ; the Milky 

 Way, 385-387; parallaxes and 

 distances of, 387-389; variable, 

 390-395 ; missing, 395 ; systems 

 of multiple, classified, ib. ; binary, 

 395-406 (see Double stars'); ne- 

 bulous, 406-419 (see Nebula); 

 seemingly innumerable, 420 ; me- 

 teors, 420-423. 



Static electricity, 282 : see Elec- 

 tricity. 



Steam, formation of, 269 ; force con- 

 verting liquids into, 277; measure 

 of its elasticity, 278 ; question of 

 its being superseded by electricity, 

 328. 



Steel, paramagnetism induced in, 336 ; 

 conditions of magnetic power re- 

 maining permanently in, 337, 338 ; 

 its elasticity affected by magnetism, 

 352. 

 Stephenson, George, quotation from, 



279-280. 



Stokes, Professor, remarks of, on gra- 

 dation of colours, 161 ; experiments 

 on fluorescence of light, 197 ; his 

 decision with regard to vibrations of 

 polarised light, 223. 

 Storms, magnetic, 344 ; varying with 



latitude, 345, 346. 



Strata of the earth, position and com- 

 parative density of, 77. 

 Stratifications, experiments showing, 



in electric light, 306, 307. 

 Struve, M., measurement by, 48 ; his 

 observations on Saturn's rings, 68 ; 

 occultation by a comet observed by 

 364 ; comet's nucleus described, ib. 

 distance of a fixed star measured by, 

 388, 389 ; catalogue of double stars 

 396 ; remarks on colour and ligh 

 of double stars, 401 ; sun's motion 

 proved by, 405. 

 Stutgardt, natural hot springs used in 



manufactories near, 231. 

 Submarine telegraph, 325-327. 



SUN. 



Sulphate of magnesia, its crystals 



boiled in alcohol, 108. 

 of nickel, effect of exposure to 



the sun, on its crystals, 107. 



of soda, its crystals, 107. 



of zinc, experiment on its crys- 

 tals, 108. 



Sulphuretted hydrogen gas, its con- 

 stituent parts, 111. 



Sumbawa, volcanic eruption of, 233. 



Summer, mean temperature of, vary- 

 ing in the same latitude, 246, 247 ; 

 atmospheric electricity in, 291. 



Sun, the, law regulating his attraction 

 of heavenly bodies, 5 ; effect of his 

 attraction on planetary orbits, mean 

 distance of planets from, 8 ; im- 

 portance of his magnitude in the 

 solar system, 12; disturbances in 

 the relative positions of planets and, 

 14 ; force modifying his intensity of 

 attraction, 16 ; resistance offered 

 by, to the power of disturbing 

 forces, 20 ; periods of conjunc- 

 tions of Jupiter, Saturn, and, 25 ; 

 influence of, on lunar motions, 

 34, 35 ; action of the planets re- 

 flected by, 37 ; eclipses of, 40, 41 ; 

 supposed constitution of, 41 ; his 

 atmosphere, 42 ; mode of finding his 

 parallax, 52, 53 ; mean distance 

 from the earth, 53 ; mass of, 55 ; 

 diameter, 56 ; comparative density, 

 attractive force, 56, 57 ; astrono- 

 mical tables of, 63 ; deductions 

 from his rotation about an axis, 

 period of, 65 ; attraction of, pro- 

 ducing a precession of the equinoxes, 

 79, 81 ; returns of, a measure of 

 time, 83-85 ; divisions of^time, de- 

 pendent on revolutions of the major 

 axis of his orbit, 86, 87 ; action on 

 tides, 92, 97 ; disturbing the equi- 

 librium of the atmosphere, 121 ; 

 dry and rainy seasons regulated by, 

 123 ; cause of decreased light and 

 heat in horizontal rays, 157, 158; 

 distance of, falsely estimated, 158 ; 

 light polarized by, 195; indications 

 of an absorptive atmosphere sur- 

 rounding, 212, 213 ; his diameter, 

 224 ; appearance of, through his 



