s, 188, 189

Harding, discovery of Juno, 75;
celestial atlas, 77

Harkness, spectrum of corona, 170;
corona of 1878, 175;
shadow of the moon in solar eclipses, 182;
light equation, 231;
distance of the sun, 237, 240, 241, 242

Harriot, observations on Halley's comet, 29

Hartley, gallium in the sun, 200, 213

Hartwig, Nova Andromedae, 394

Hasselberg, metallic spectra, 211;
spectra of comets, 342, 357;
of Nova Andromedae, 395

Hastings, composition of photosphere, 152;
observations at Caroline Island, 181;
Saturn's dusky ring, 299

Hegel, number of the planets, 73

Heis, radiant of Andromedes, 334

Heliometer, 34, 234, 237, 238, 240

Helium, a constituent of prominences, 194, 195, 199;
no absorption by, in solar spectrum, 213;
absorptive action in first-type stars, 376;
bright in gaseous stars, 377, 378, 380;
in Orion nebula, 407

Helmholtz, gravitational theory of sun-heat, 311-313

Hencke, discoveries of minor planets, 76

Henderson, parallax of Alpha Centauri, 36, 416;
observation of chromosphere, 68

Henry, Paul and Prosper, lunar twilight, 264;
markings on Uranus, 303;
photograph of Saturn, 408;
photographs of nebulae in the Pleiades, 410, 411;
stellar photography, 413;
plane mirrors, 438

Herrick and Bradley, duplication of Biela's comet, 96

Herschel, Alexander S., cometary and meteoric orbits, 332

Herschel, Caroline, her brother's assistant, 12;
observation of Encke's comet, 90

Herschel, Colonel, spectrum of prominences, 168;
of reversing layer, 172;
of corona, 174

Herschel, Sir John, life and work, 45-50;
Magellanic clouds, 47, 422;
sun-spots, 58, 59, 144;
solar flames, 68;
anticipation of Neptune's discovery, 81;
status of Hyperion, 85;
Biela's comet, 95;
Halley's, 102;
comet of 1843, 103;
sixth star in "trapezium," 113;
grinding of specula, 116;
spectrum analysis, 136;
solar photography, 145, 154;
solar constitution, 151;
shadow round eclipsed sun, 182;
actinometrical experiments, 216;
solar heat, 217;
climate and eccentricity, 259;
lunar atmosphere, 263;
surface of Mars, 276;
Andromeda nebula, 396;
observations of nebulae, 404;
double nebulae, 412

Herschel, Sir William, discovery of Uranus, 5;
founder of sidereal astronomy, 9;
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