286, 287;
collective volume, 287;
atmospheres, 288

Plantade, halo round Mercury, 244

Pleiades, community of movement near, 41;
photographed spectra, 385;
measurements, 410;
photographs, 410, 411;
nebulae, 410, 411

Pluecker, hydrogen in sun, 212

Plummer, solar translation, 39;
Encke's comet, 99

Plutarch, solar corona, 65

Pogson, prominence spectrum, 168;
reversing layer, 172;
discovery of a comet, 335, 339;
new star in cluster, 395

Pond, errors of Greenwich quadrant, 28;
controversy with Brinkley, 33

Pons, discoveries of comets, 90, 94, 365

Pontecoulant, return of Halley's comet, 101

Poor, C. Lane, calculation of Lexell's comet, 367

Porter, solar translation, 40

Pouillet, solar constant, 216, 225;
temperature of the sun, 217;
of space, 270

Poynting, mean density of the earth, 261

Prince, glow round Venus, 253

Pritchard, parallax of Beta Aurigae, 388;
photographic determinations of stellar parallax, 417;
photometric catalogue, 420

Pritchett, corona of January, 1889, 186;
red spot on Jupiter, 294

Proctor, glare theory of corona, 182;
speed of ejections from sun, 205;
transit of Venus, 233;
distance of sun, 236;
atmosphere of Venus, 254;
rotation of Mars, 275;
map and canals of Mars, 278, 279;
condition of great planets, 289;
Nova Andromedae, 403;
status of nebulae, 422, 423;
structure of Milky Way, 424;
star drift, 426

Procyon, satellite, 42; parallax, 417

Prominences, observed in 1842, 63, 64, 68;
described by Vassenius, 68;
observed in 1851, 70;
photographed during eclipse, 167, 188, 190;
without eclipse, 197, 198;
spectrum, 168, 178, 194, 195, 198, 199;
spectroscopic method of observing, 168-170, 194-196;
white, 183, 184;
chemistry, 195, 199;
classification, 196;
distribution, 199;
movements in, 204-206;
heat of development, 220

Quetelet, periodicity of August meteors, 329

Ranyard, drawing of sun-spot, 101;
coronal types, 175, 185;
lunar atmosphere, 265;
Jupiter's markings, 297;
meteors from fixed radiants, 341;
cometary trains, 348;
tenuity of nebulae, 409

Rayet, spectrum of prominences, 168, 170

Red spot on Jupiter, 293, 296

Reduction of observations, 31;
Bessel's improvements, 32, 122;
Baily's, 60