rotation of Jupiter, 290;
red spot, 295;
periodicity of markings, 297;
rotation of Saturn, 302;
meteors of 1885, 336;
of 1892, 338;
stationary radiants, 341

Denza, meteors of 1872, 334

Derham, theory of sun-spots, 53;
ashen light on Venus, 255

Deslandres, eclipse expedition, 187;
rotation of corona, 188;
prominence photography, 198;
hydrogen spectrum in prominences, 198, 383;
photographs of Jupiter, 297;
radial movements of Saturn's rings, 300;
helium absorption in stars, 376;
stellar radial velocities, 406

Diffraction, corona explained by, 67, 70, 181;
spectrum, 139, 210, 223, 439

Dissociation in the sun, 152, 206-210;
in space, 312

Doberck, orbits of double stars, 38, 418

Dollond, discovery of achromatic telescope, 4, 112

Donati, discovery of comet, 323;
spectra of comets, 342;
of stars, 372

Doppler, effect of motion on light, 200

Douglass, observations of Jupiter's satellites, 292

Downing, perturbations of the Leonids, 338

Draper, H., ultra-violet spectrum, 210;
oxygen in sun, 213;
photographs of the moon, 268;
of Jupiter's spectrum, 291;
of Tebbutt's comet, 354;
of spectrum of Vega, 382;
of Orion nebula 407

Draper, J. W., lunar photographs, 152;
distribution of energy in spectrum, 223 _note_

Draper Memorial, 384-386

Dreyer, Catalogue of Nebulae, 50

Dulong and Petit, law of radiation, 217, 219

Duner, spectra of sun-spots, 156;
spectroscopic measurement of solar rotation, 203;
spectroscopic star catalogue, 381

Dunkin, solar translation, 39

Duponchel, sun-spot period, 163

Durchmusterung, Bonn, 33, 412;
Cape photographic, 412;
parallax, 418;
photometric, 421

Dyson, coronal photographs, 190

Earth, mean density, 60, 261;
knowledge regarding, 257;
rigidity, 257, 259;
variation of latitude, 258, 259;
figure, 261, 262;
effects of tidal friction, 271-273;
bodily tides, 316;
primitive disruption, 317

Easton, structure of Milky Way, 423, 424

Ebert, coronoidal discharges, 192

Eclipse, solar, of 1836, 61;
of 1842, 62-65, 67, 69;
of 1851, 69, 70, 166;
of 1860, 166, 167;
of 1868, 167-170;
of 1869, 170;
of 1870, 171;
of 1871, 173;
of 1878, 174-177;
of 1882, 177, 178;
of 1883, 180, 181;
of 1885, 183;