uzeau, solar parallax, 240

Howlett, sun-spot observations, 155

Hubbard, period of comet of 1843, 105, 351

Huggins, Sir William, spectroscopic observations of prominences,
170, 195;
hydrogen spectrum in stars, 178, 198;
daylight coronal photography, 178, 179;
repulsive action in corona, 191;
stellar motions in line of sight, 201, 386, 387;
transit of Mercury, 245;
occultation of a star, 263;
snowcaps on Mars, 276;
spectrum of Mars, 277;
of Jupiter, 290;
Jovian markings and sun-spots, 297;
spectrum of Uranus, 304;
of comets, 342, 343;
photographs, 354, 357;
stellar spectroscopy, 373;
colours of stars, 374;
classification of star spectra, 376;
photographs, 382, 383, 438;
stellar chemistry, 381, 382;
spectra of new stars, 393, 395;
theory of Nova Aurigae, 397;
spectra of nebulae, 401, 402, 407;
nebular radial movement, 405

Huggins, Sir William and Lady, photograph of Uranian spectrum, 305;
spectra of Wolf-Rayet stars, 380;
ultra-violet spectrum of Sirius, 383;
nitrogen in stars, 384;
spectrum of Nova Aurigae, 396-398;
of Andromeda nebula, 403;
of Orion nebula, 407

Humboldt, sun-spot period, 126;
magnetic observations, 127;
meteoric shower, 329

Hussey, T. J., search for Neptune, 79

Hussey, W. J., cloud effects on Mars, 281;
cometary appendages, 369;
period of Delta Equulei, 419;
discoveries of double stars, 419, 433

Huygens, stellar parallax, 16;
Orion nebula, 22;
discovery of Titan, 84;
Saturn's ring, 85, 301;
spot on Mars, 275

Hydrogen, a constituent of prominences, 168, 195, 199;
spectrum, 178, 198, 383, 384;
absorption in stars, 198, 373, 381-383;
in sun, 211;
theoretical material of comets' tails, 347;
emissions in stars, 377-380, 384, 393, 397;
in nebulae, 402, 407

Innes, Southern double stars, 419

Jacoby, measurement of Rutherfurd's plates, 410;
Pritchard's parallax work, 417

Janssen, photographs of the sun, 165;
spectroscopic observations of prominences, 168, 169;
escape from Paris in a balloon, 171;
coronal spectrum, 173, 181;
coronal photographs, 181;
rarefaction of chromospheric gases, 182;
oxygen absorption in solar spectrum, 214;
transit of 1874, 234;
spectrum of Venus, 254;
of Saturn, 303;
photographs of Tebbutt'