bservations of prominences, 194, 196, 199;
absence of helium absorption, 213;
temperature of the sun, 218;
solar atmospheric absorption, 221;
Martian canals, 279;
spectrum of Uranus, 304;
of Coggia's comet, 343;
stellar spectral researches, 372, 373;
carbon stars, 372, 381;
gaseous stars, 377

See, stellar orbits, 42, 46;
measures of Neptune, 84;
measures of Uranus, 304;
belts of Neptune, 306;
colour of Sirius, 375 _note_;
southern double stars, 419;
evolution of stellar systems, 420

Seeliger, photometry of Saturn's rings, 299;
rationale of new stars, 396

Seidel, stellar photometry, 420

Sherman, spectrum of Nova Andromedae, 395

Short, reflectors, 4, 109, 115, 121;
chromosphere, 68;
satellite of Venus, 256;
striation of Saturn's rings, 299

Sidereal science, foundation, 9, 442;
condition in 1785, 10;
progress, 50

Sidgreaves, spots and faculae, 159

Siemens, regenerative theory of the sun, 312

Simony, photographs of ultra-violet spectrum, 215

Sirius, a binary star, 41;
mass, 42;
parallax, 42, 416;
spectrum, 133, 373, 383;
former redness, 375 _note_;
radial movement, 386, 387

Smyth, Admiral, Donati's comet, 324

Smyth, Piazzi, oxygen spectrum, 215;
lunar radiations, 269;
expedition to Teneriffe, 434

Solar constant, 216, 225

Solar spectrum, fixed lines in, 133-135;
maps, 133, 136, 206, 210, 211, 224, 440;
distribution of energy, 222, 223

Solar system, translation through space, 15, 39, 40, 406;
development, 308, 309, 313-316, 322;
complexity, 441

Soret, solar temperature, 218

South, observations of double stars, 45;
12-inch lens, 113;
Rosse reflector, 117;
occultation by Mars, 276

Spectroscopic binaries, 387-391

Spectrum analysis, defined, 130;
first experiments, 131, 132;
applied to the sun, 133-135, 156;
to the stars, 133, 372, 373;
Kirchhoff's theorem, 135;
elementary principles, 139, 140;
effects on science, 141, 142;
radial motion determined by, 201, 386;
investigations of comets by, 342, 343;
of new stars, 393, 399;
of nebulae, 401-403

Spencer, position of nebulae, 422

Spitaler, attendants on Brooks's comet, 366

Spitta, transits of Jupiter's satellites, 292

Sporer, solar rotation, 148, 149;
chromosphere, 199, 200

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