INDEX.
- A.
- Aberration (see Chromatic Aberration, Spherical Aberration)
- Absorption, general and selective, 403, 408;
- spectroscope arranged for showing, 409
- Adjustment of the transit instrument, 238
- Adjustments of the Equatorial (Chap. XXI.), 328
- Achromaticity of Huyghen’s eyepiece, 110
- Achromatic lenses, 84, 86
- Achromatism, 126
- Airy’s transit circle, 284
- Alexandrian Museum, astronomical observations, 19
- Alt-azimuth, 287, 289
- Altitudes, instrument used by Ptolemy for measuring, 35
- Aluminium, line spectrum of, 406;
- the sun, 417
- Analyser for polarization of light, 443, 450
- Anaximander, his theory of the form of the earth, 6;
- Anchor escapement, 197
- Angles of position, measurement of, 358-366, 372
- Ångström, spectrum analysis, 402, 412;
- wave-lengths, 406
- Annealing of lenses and specula, 121
- Archimedes, clocks used by, 176
- Arcturus, heat of, 385
- Argelander, magnitudes of stars, 382
- Aries, its position in the zodiac, 34
- Aristillus, his observations in the Alexandrian Museum, 19
- Armillæ Æquatoriæ of Tycho Brahe, 26, 41, 45;
- his Armillæ Zodiacales, 28
- Ascension, Right (see Right Ascension)
- Arctic circle, Euclid’s observations of stars in the, 10
- Astrolabe, invented by Hipparchus, 25;
- Astronomical clock, 240 (see Clock)
- ASTRONOMICAL PHYSICS (Book VI.), 371
- Astronomy of Precision, Instruments used in (Chap. XIX.), 284-290
- Astrophotometer, Zöllner’s, 379
- Autolycus, first map of the stars by, 8, 9
- Automatic spectroscope, 397
- Auzout, invention of micrometer ascribed to, 219, 221
- Axis of collimation, 218, 220
- B.
- Barium, in the sun, 419
- Barlow, correction of aberration in lenses, 88;
- Barometrical pressure, its effect on the pendulum, 193
- Berthon’s dynameter, 116
- Bessel’s transit instrument, 284
- Binary stars, 351, 359, 360
- Blair (Dr.), object-glasses, 88
- Bloxam’s improved gravity escapement, 201
- Bond (Prof.), spring governor, 320, 321;
- celestial photography, 463
- Bouguer’s photometer, 379
- Brahe, Tycho (see Tycho Brahe)
- Brewster (Sir David), his list of Tycho Brahe’s instruments, 38;
- spectrum analysis, 410
- British Horological Institute, time signals, 280
- Browning’s method of silvering glass specula, 137;
- Bunsen (Ernest de), on ancient astronomical observations, 6
- Bunsen (Prof.) spectroscope, 396;
- C.
- Calcium, line spectra of, 406, 418
- Cambridge Observatory (U.S.), equatorial at, 339;
- Camera, enlarging, for celestial photography, 458
- Canada balsam, its power of refracting light, 447
- Candles used to measure time, 176
- Canopus, observations of, by Posidonius, 8
- Cassegrain’s reflecting telescope, 103, 149, 169;
- with Mr. Grubb’s mounting, 301
- Casting lenses and specula, 121
- Castor, photograph of, 478
- Catalogues of stars (see Stars)
- Celestial globe, 23
- Celestial Photography (Chap. XXXI., XXXII.), 454
- Chair, observing, for equatorial telescopes, 339
- Chaldeans, their observations of the motions of the moon, 4;
- early use of the gnomon, 16
- Chance and Feil, manufacture of glass discs, 119, 305
- Chemistry of the Stars (Chap. XXVII.-XXX.), 386-453
- Chinese, observations of conjunctions of planets, 4, 5;
- Chromatic aberration of object-glasses and eyepieces, 87, 109, 123
- Chronograph, The (Chap. XVII.), 253-270
- “Chronographic method” of transit observation, 259
- Chronograph at Greenwich Observatory, 260-264
- Chronometer, The (Chap. XIII.), rise and progress of time-keeping, 206-210;
- Chronometers used for determining “local time,” 281
- Chronophers, for distributing “Greenwich time,” 275, 276
- Cincinnati Observatory, 338
- Circle, the; its first application as an astronomical instrument, 6, 7, 8, 10;
- Circles, great, defined by Euclid, 12
- Circle Reading (Chap. XIV.), 211-217;
- Circle, Transit (see Transit Circle)
- Circle, meridian, at Cambridge (U.S.), 248;
- Circumpolar stars, 239
- Clarke (Alvan), improvement in telescope lenses, 305;
- Clement, inventor of the anchor escapement, 197
- Clepsydras, 36
- Clock, The (Chap. XIII.), 175-205;
- ancient escapement, 177;
- crown wheel, 178;
- clock train, 180;
- winding arrangements, 181;
- pendulum, 183;
- cycloidal pendulum, 185;
- compensating pendulums, 187;
- Graham’s, Harrison’s, and Greenwich pendulums, 188;
- clock at Royal Observatory, Greenwich, 194;
- escapements, 196;
- anchor escapement, 197;
- Graham’s dead-beat, 199;
- Mudge’s gravity escapement, 200;
- escapement of clock at Greenwich, 203;
- arrangements at Edinburgh Observatory, 269;
- astronomical, 240, 244, 245, 346;
- sidereal, 254, 256, 266;
- solar, 254;
- standard, at Greenwich, 194, 203, 204, 271, 274
- Clock, driving, for large telescopes, 318
- Clocks driven and controlled by electricity, 272
- Clock stars, 267
- Clock tower at Westminster, 277
- Coggia’s comet, its light polarized, 450
- Collimation and collimation-error in the transit instrument and equatorial, 238, 247, 328
- Colour, amount produced by a lens, 81, 84, 86;
- Comet of 1677, discovered by Tycho Brahe, 47
- Comet, measurement of the angle of position of its axis, 359
- Comparison prism of the spectroscope, 423
- Compensating balance, 207
- Compensating pendulums, 187-193
- Composite mounting of large telescopes, 310
- Concave lenses (see Lenses)
- Concave mirrors (see Mirrors)
- Conjugate images, 64
- Conjunctions of planets, first observations, 4
- Constellations, first observations, 5, 9;
- Orion and its neighbourhood, 156
- Convex lenses (see Lenses)
- Convex mirrors (see Mirrors)
- Cooke, adjustment of object-glasses, 141;
- Copernicus, parallactic rules of, 41
- Copernicus (lunar crater), 354
- Cross wires for circle reading, 212, 216, 218;
- Crown-glass prisms, 83, 84;
- Crystals of Iceland spar, double refraction by (see Iceland Spar)
- Culmination of stars, first observations of, 5
- Cycloidal pendulum, 185
- D.
- Dawes, solar eyepiece, 114, 115, 349;
- photometry, 378
- Day, solar and sidereal, 253, 254, 256
- Day eyepiece, 113
- Days, first reckoning of, 19;
- measurement of, 176
- Dead-beat escapement, 198
- Deal time-ball, 275, 279
- Declination, 24, 234, 241, 243, 251;
- measured by Tycho Brahe, 45
- Declination axis of the equatorial, 299, 308, 327, 328
- Defining power of the modern telescope, 160, 164;
- stars in Orion a test of, 165
- Degrees, division of the circle into, 8, 17, 21
- De La Rue (Warren, F.R.S.), his reflecting telescope, 108;
- Denderah, the zodiac of, 7
- Dent (E. & Co.), clock at Royal Observatory, Greenwich, 194, 203, 204, 271, 274
- Detached lever escapement, 208
- Deviation of light, 79, 82
- Deviation error in the transit instrument, 240, 248
- Dials of ancient clocks, 257
- Diagonal scale, Digges’, 213
- Differential observations made with the equatorial, 367
- Digges’ diagonal scale, 213
- Diogenes Laertes, on the invention of the gnomon, 16
- Dioptrics, Kepler’s treatise on, 386
- Direct vision spectroscope, 431
- Dispersion of light by prism, 79, 80, 82
- Dividing power of telescopes, 165
- Dollond, experiments with lenses, 85;
- Dome form of observatory, 338, 339
- Double stars, 351, 359;
- measurement of, 360
- Double-image micrometer, 225, 229
- Double refraction by crystals of Iceland spar (see Iceland Spar)
- Driving clock, for large telescopes, 318, 346
- Drum form of observatory, 338
- Dundee time signal, 278
- E.
- Earth, The, its position in Ptolemy’s system, 3;
- Eclipses, first observations of, 4;
- eclipses of Jupiter’s moons;
- eclipses, solar, photograph of, 474
- Ecliptic, plane of the, 13, 14;
- Ecliptic astrolabe of Tycho Brahe, 28
- Edinburgh Observatory, clock arrangements at, 269;
- Egyptians, their record of eclipses, 4;
- zodiac of Denderah, 7
- Eichens, his equatorial telescope at Paris, 314, 315;
- siderostat constructed by him, 344
- Electricity, its application to the chronograph, 265;
- to driving and controlling clocks, 272
- Electric lamp, 404;
- arranged for spectrum analysis, 405
- Emery used in grinding lenses and specula, 127
- English mounting of large telescopes, 310
- Equation of time, 254
- EQUATORIAL, THE (Book V.), 293-368 (see Telescopes)
- Equatorial Observatory, The (Chap. XXII.), 337-342 (see Observatories)
- Equatorial, The; its ordinary work, (Chap. XXIV.), 349-368
- Equinoctial circle, observations of, by Euclid, 11
- Equinoxes, first observations of, 15, 16, 17, 22;
- precession of the, 33
- Eratosthenes, observations of, 17;
- Erecting eyepiece, 113
- Errors, collimation and deviation, in the transit instrument, 238, 240, 247, 328
- Errors; personal equation, 259;
- adjustments of the equatorial, 329
- Ertel, vertical circle designed by, 290
- Escapements of clocks, 196-205;
- Ethereal vibrations, 373, 401, 410, 420, 449, 450
- Euclid, his observations of the stars, 8, 9, 10;
- Extra-meridional observations, first employment of, 23, 25
- “Eye and ear” method in transit observations, 259
- Eyeball, section of the, 66
- Eyepieces, Huyghen’s, 110;
- Eyepiece of Greenwich transit circle, 246;
- of transit instrument, 257
- F.
- Faye, M., celestial photography, 456
- Feil and Chance, manufacture of flint glass discs, 119, 305
- Fixed stars (see Stars)
- Flame of salts in a Bunsen’s burner, 407
- Flint-glass prisms, 83, 84;
- Flint-glass, improvements in the manufacture of discs of, 118, 119, 305
- Focal length of telescopes, 82, 458;
- Foucault; his reflecting telescope, 108;
- Fraunhofer; manufacture of flint-glass discs, 118;
- Frederick II. of Denmark, his patronage of Tycho Brahe, 38
- Fusee for chronometers, 209
- G.
- Galileo; his telescopes, 73, 78;
- Gascoigne, eyepieces and circle reading, 212;
- cross wires for “telescopic sight,” 219
- Gateshead, Mr. Newall’s refractor, 302
- Geissler’s tubes, 413
- German mounting of large telescopes, 299
- Gizeh, great pyramid of, an astronomical instrument, 6
- Glasgow, electric time-gun, 278
- Glass, injurious effects of the duty on, 305
- Glass specula, methods of silvering, 137
- Globe, celestial, 23;
- terrestrial, 23
- Gnomon; its invention and early use, 16;
- Graham; dead-beat escapement, 192, 199;
- mercurial pendulum, 188
- Gravity escapement, 200, 202
- Greeks, their early use of the gnomon, 16
- Greenwich, Royal Observatory; perspective view and plan of transit circle, 243, 245, 251;
- “Greenwich Time” and the use made of it (Chap. XVIII.), 271-283
- Gregorian telescope, 149
- Gridiron pendulum, 188, 189, 192
- Grinding of lenses and specula, 127
- Grubb; production and polishing of metallic specula, 121, 134;
- Guinand, manufacture of flint-glass discs, 118
- Guns fired as time-signals, 278
- H.
- Haliburton, on ancient astronomical observations, 6
- Hall; experiments with lenses, 85;
- manufacture of flint-glass discs, 118
- Harcourt, Vernon, experiments with phosphatic glass, 123
- Harrison’s gridiron pendulum, 188
- Heat of Stars, Determination of (Chap. XXVI.), 377-385
- Heliometer, 224
- Heliostat, 423, 458
- Henry (Prof.), radiation of heat from sun-spots, 385
- Herschel (Sir John), lenses corrected for aberration, 88;
- Herschel, Sir William, his reflecting telescopes, 103, 108;
- Herschel-Browning direct-vision prism, 400
- Hipparchus, trigonometrical tables constructed by, 17;
- Hittorf, spectrum analysis, 413
- Holmes (N. J.), his proposal of the electric time-gun, 278
- Hooke, improvement in clock escapements, 196;
- Horizon, the first astronomical instrument, 4, 7, 8;
- defined by Euclid, 12
- Horological Institute, time-signals, 280
- Hours, first reckoning of, 19;
- measurement of, 176
- Hour circle of the equatorial telescope, 328, 335
- Huen, island of, granted to Tycho Brahe, 38
- Huggins (Dr.), telespectroscope, 429, 432
- Huyghens; telescopes used by, 81;
- Hydrogen in the sun, 435
- I.
- Iceland spar crystals; double refraction by, 226, 228;
- Illuminating power of the telescope, 158, 166, 168, 169;
- stars in Orion, a test of, 164
- Images, double, seen through Iceland spar, 227
- Inclination of the earth’s axis, 14, 17
- Inclination of the ecliptic, 17;
- measured by Eratosthenes, 19
- Index error, adjustments of the equatorial, 330
- Iron, line spectrum of, 406, 418
- Irrationality of the spectrum, 87
- J.
- Janssen (Dr.), solar photography, 471;
- discoveries in solar physics, 472
- Jupiter, in Ptolemy’s system, 3;
- Jupiter’s moons, observation of their eclipses to determine “local time,” 282
- K.
- Kepler’s treatise on dioptrics, 386
- Kew Observatory, photographs of the sun and sun-spots, 460, 465, 470, 475
- Kirchhoff; spectroscope, 396;
- Kitchener (Dr.), improved eyepiece, 113;
- stars in Orion, 164
- Knobel’s photometer, 378
- Knott, star magnitudes, 381
- L.
- Lamp for equatorial telescope, 325
- Lamp, electric (see Electric Lamp)
- Lassell; his Newtonian telescope, 108, 311;
- Latitude; observations of Posidonius, 8;
- parallels of, 23
- Lattice-work for tubes of telescopes, 172
- Lenses; action of, 55, 58, 85;
- Lens, crystalline, of the eye, 67
- Lewis (Sir G. C.), his “Astronomy of the Ancients,” 9
- Liebig, improvement in specula, 117
- Light; refraction, 55-72;
- deviation and dispersion, 79, 80, 82, 83;
- decomposition and recomposition, 83;
- reflection, 90-99;
- action of a reflecting surface, 91;
- angles of incidence and reflection, 92;
- concave and convex mirrors, 94-98;
- velocity of, 159;
- loss due to reflection, 168;
- effective, in reflectors, 169;
- vibration of particles, 373, 401;
- polarization, 441-453
- Light of Stars, Determination of (Chap. XXVI.), 377-385
- Lindsay (Lord), siderostat at his observatory, 347
- Local time, 281
- Longitude, meridians of, 23;
- M.
- Magnesium vapour; colour of, 416;
- in the sun, 435
- Magnifying power of large telescopes, 154, 155;
- stars in Orion, a test of, 163
- Magnitude of stars, 377
- Malus, discovery of polarization by reflection, 442, 448
- Malvasia (Marquis), his micrometer, 219, 221
- Manlius, gnomon erected by him at Rome, 18
- Maps of the stars (see Stars)
- Mars, in Ptolemy’s system, 3;
- Martin’s method of silvering glass specula, 138
- Mauritius, photoheliograph at, 469
- Mean time, 254
- Mean solar time clock at Greenwich, 268
- Melbourne Observatory, great reflecting telescope, 312, 313, 337;
- Mercurial pendulum, 187, 188, 192
- Mercury, in Ptolemy’s system, 3;
- Meridian, defined by Euclid, 12
- Meridional observations, first employment of, 20
- Meridian of Greenwich, 252
- Meridian circle, the first, 20;
- at Cambridge (U.S.), 248
- Meridians of longitude (see Longitude)
- MERIDIONAL OBSERVATIONS, MODERN (Book IV.), 233-290
- Merz (M.), manufacture of flint-glass discs, 119;
- Metallic specula, 120, 171
- Meton, meridian observations by, 25
- Meudon Observatory, solar photography at, 470
- Micrometer, The (Chap. XV.), 218-232;
- Microscopes, for reading transit circles, 247;
- for Newall’s telescope, 307
- Middlesborough, time signal, 278
- Milky Way, observations of Euclid, 11
- Miller, spectrum analysis, 410
- Mirrors, concave and convex, 94-98
- Mirrors for reflecting telescopes (see Specula)
- MODERN MERIDIONAL OBSERVATIONS (Book IV.), 233-290
- Molecular vibration, 373, 401, 410, 429, 449, 450
- Months, first observations of, 5
- Moon, The, in Ptolemy’s system, 3;
- motions observed by the Chaldeans, 4;
- parallax observed by Ptolemy, 35;
- used by Hipparchus to determine longitude, 44;
- as a telescopic object, 350;
- the lunar crater, Copernicus, 354;
- measurement of shadow thrown by a lunar hill, 355;
- photographs and stereographs, 459, 464, 465, 466;
- part of Beer and Mädler’s map, 476;
- of De La Rue’s photograph, 477
- Mounting of Large Telescopes (Chap. XX.), 293-327
- Mounting of specula for reflecting telescopes, 144, 149, 169
- Mudge, grinding and polishing specula, 129;
- gravity escapement, 200
- Mural circle, 241, 242
- Mural quadrant, Tycho Brahe’s, 233, 235
- Multiple stars, 351
- N.
- Nebulæ, 351
- Nebula of Orion, 157, 158
- Neptune, as a telescopic object, 351
- Newall’s equatorial refractor, 302;
- Newcastle, time signals, 278
- Newton (Sir Isaac), on refracting telescopes, 82;
- Newtonian reflector, 149;
- Nicols’ prism, 115;
- North pole, diagram illustrating how it is found, 249, 251
- O.
- Object-glasses, production of, 118, 119;
- Object-glass prism, 426
- Observatories [see Alexandrian Museum, Cambridge (U.S.), Cincinnati, Edinburgh, Greenwich, Huen (Tycho Brahe’s), Kew, Lord Lindsay’s, Mauritius, Melbourne, Meudon, Paris, Potsdam, Vienna, Washington]
- Observing chair for equatorial telescopes, 339
- Optical action of the eye, 67;
- Optical qualities of telescopes, permanence of, 170
- Optic axis in crystals of Iceland spar, 228
- “Optick tube,” telescope so first called, 55, 139-151
- Orion, first observations of, 5;
- P.
- Parallactic rules, 51;
- Parallax of the moon, observed by Ptolemy, 35
- Paris Observatory, reflecting equatorial telescope, 314, 315, 337;
- Pendulum, 183, 185, 187, 188
- Personal equation, 259
- Phosphatic glass for lenses, 123
- Photography, Celestial (Chap. XXXI., XXXII.), 454-483
- Photography, stellar, 172
- Photoheliograph, for photographs of the sun, 460, 470;
- for transit of Venus (1874), 461
- Photometry, 373, 377
- PHYSICS, ASTRONOMICAL (Book VI.), 371
- Physical Inquiry, General Field of (Chap. XXV.), 371-376
- Picard, transit circle, 284
- Pisces, its position in the zodiac, 34
- Pitch employed in polishing lenses and specula, 128, 132
- Plane of the ecliptic, 13, 14
- Planets, in Ptolemy’s system, 3;
- Pleiades, the first observations of, 5
- Plücker, spectrum analysis, 413
- Pogson, star magnitudes, 381, 382
- Pointers of pre-telescopic instruments, 35, 49, 214, 216
- Polar axis of the equatorial, 299, 302, 308, 311, 312, 324, 328, 329, 346
- Polariscope, 441-453
- Polarization of light, 441-453
- Pole, North, 238;
- diagram illustrating how it is found, 249
- Pole star, first observations of, 6;
- Polishing lenses and specula, 128, 171;
- Posidonius, measurement of the earth’s circumference, 8
- Position circle, 353
- Position micrometer, 353, 358
- Post Office Telegraphs, for distribution of Greenwich time, 275
- Potsdam, photoheliograph at, 469
- Precession of the equinoxes, 33
- Prime-vertical, 285
- Prime-vertical instrument, 287
- Primum mobile of Ptolemy, 3
- Prisms, action of, 55;
- Ptolemy, the Heavens according to, 3;
- Purbach, observation of altitudes by, 36
- Pyramids, the first constructed astronomical instruments, 5, 6
- Q.
- Quadrants used by Tycho Brahe, 38;
- his quadrans maximus, 48
- Quadrant, mural, 233, 235
- Quartz crystals for polarizing light, 450, 452
- R.
- Radiation of stars, visual, 383;
- thermal, 385
- Radiation, general and selective, 403, 408
- Ramsden’s eyepiece, 112, 212
- Reading microscopes, for Greenwich and Cambridge (U.S.) transit circles, 247;
- for Newall’s telescope, 307
- Red stars (see Colour of Stars)
- Reflection of light (see Light)
- Reflecting telescopes (see Telescope)
- Reflective powers, Sir John Herschel’s table of, 168
- Reflector, diagonal, for solar observations, 114
- Reflecting and refracting telescopes compared, 170
- Reflex zenith-tube at Greenwich, 286
- Refracting telescopes (see Telescopes)
- Refracting and reflecting telescopes compared, 170
- Refraction of light (see Light)
- Refraction, double, by crystals of Iceland spar (see Iceland Spar)
- Refrangibility of colours, 387;
- of light, 420
- Regiomontanus, altitudes measured by, 36
- Regulation of clocks by electricity, 272
- Rising of stars (see Stars)
- Right ascension, 24, 234, 241, 249, 257;
- Ring micrometer, 368
- Robinson (Dr.),
- Rockets fired as time signals, 281
- Römer, wires in a transit eyepiece, 220;
- transit circle and transit instrument, 284
- Rosse (Lord), his reflecting telescope, 108, 294, 311, 312;
- Royal Observatory, Greenwich (see Greenwich)
- Rudolph II. (Emperor), his patronage of Tycho Brahe, 42
- Rumford’s photometer, 377
- Rutherfurd, his work in celestial photography, 455, 464, 466, 471, 477, 480
- S.
- Salts, flame of, in a Bunsen’s burner, 407
- Sand clocks and sand glasses, 176
- Saturn, in Ptolemy’s system, 3;
- Savart’s analyser for polarization of light, 452
- Scarphie, employed by Eratosthenes, 19
- Scheiner’s telescope, 78
- Seasons, The, 15, 16
- Secchi (Father), direct-vision star spectroscope, 431;
- stellar spectra, 433
- Setting of stars (see Stars)
- Sextants used by Tycho Brahe, 38, 50
- Sidereal clock, 254, 266 (see Clock)
- Sidereal day, 256
- Sidereal time, 240, 254, 324
- Siderostat, The (Chap. XXIII.), 343-348, 461;
- at Lord Lindsay’s Observatory, 347
- Signals for distributing “Greenwich time,” 278
- Signals, time, 281, 283
- Signs of the zodiac (see Zodiac)
- Silver-on-glass reflector at the Paris Observatory, 316
- Silvering glass specula, modes of, 137;
- silvered glass reflectors, 171
- Simms, his introduction of the collimator in the spectroscope, 393, 425
- Sirius, first observations of, 5;
- spectrum of, 432
- Slough, Sir Wm. Herschel’s telescope at, 294
- Smyth (Admiral), stars in Orion, 165;
- Smyth (Prof. Piazzi), on the pyramids as astronomical instruments, 6;
- Sodium, discovery of its presence in the sun, 412
- Solar photography, 459, 465
- Solar spectroscope, 435;
- Browning’s and Grubb’s forms, 428
- Solar spectrum, 390, 391, 392, 423, 433, 436, 438, 439;
- Solar time, 253, 255
- Solstices, first observations of the, 15, 16, 17, 22
- Southing of stars, 234
- SPACE MEASURERS (Book III.), 135-232;
- Space-penetrating power of the telescope, 154;
- stars in Orion, a test of, 165
- Spectroscope, construction of the, 393-400;
- Spectrum produced by prisms, irrationality of the, 86, 87
- Spectrum, solar, 390, 391, 392
- Spectrum analysis, principles of, 401-421
- Specula, production of, 117, 120;
- Spherical aberration, 87;
- Sprengel pump, 413
- Spring governor of driving-clock for large telescopes, 319, 320
- “Spurious disc” of fixed stars, 163
- Standard clock at Edinburgh Observatory, 272
- Standard sidereal clock of Greenwich Observatory, 267
- Standard solar time clock of Greenwich Observatory, 267
- Stars, Chemistry of the (Chap. XXVII.-XXX.), 386-453
- Stars, Light and Heat of (Chap. XXVI.), 377;
- Stars, first observations of the, 4, 5, 6, 7;
- first maps of, 8;
- observations of Autolycus, Euclid, and Posidonius, 8, 10;
- first catalogues of, 19;
- latitude and longitude of, 24, 30;
- positions tabulated by Hipparchus, 30;
- Tycho Brahe’s catalogue and map of, 42, 44;
- stars in Gemini seen through a large telescope, 155;
- nebula of Orion, 157;
- Orion and its neighbourhood, 156;
- double, as defined by telescopes of different power, 162, 164, 167, 167;
- distance of stars from the earth, 159;
- facilities for observing Orion, its stars, a test for power of telescopes, 164;
- stellar photography, 172, 465, 466, 467, 478;
- their rising and setting as measurers of time, 176;
- double, measurement of, 359, 361, 362;
- spectrum of red star, 433
- Star-clusters, double and multiple stars, 351
- Star-spectra, from Father Secchi’s observations, 433;
- photographs of, 479
- Star spectroscopes, at Cambridge (U.S.), 430;
- direct vision, 431
- Star-time (see Sidereal Time)
- Steinheil, improvement of specula, 117
- Stellar day, 256
- Stereographs of the moon, 465, 466
- Sternberg, Tycho Brahe’s Observatory, 38
- Stewart (Prof. Balfour), spectrum analysis, 402;
- solar photography, 471
- Stokes (Prof.), experiments with phosphatic glass, 123;
- Stone, thermopile at Greenwich, 384
- Strontium in the sun, 419
- Struve, transit instrument, 285;
- Sun, The; in Ptolemy’s system, 3;
- first determination of its yearly course, 8, 15;
- course in the zodiac, described by Autolycus, 9;
- altitude determined by the gnomon, 16, 18;
- telescopes for observing, 114;
- “mean sun,” 256;
- as a telescopic object, 349;
- presence of sodium in, 412, 415;
- vapour of other metals, 417;
- absorption spectrum, 418;
- telespectroscopic observations, 436;
- of the chromosphere, 437;
- sun-storms, 438, 439;
- photographs, 459, 469, 470
- Sun-dials, 18
- Sun-spots observed by Galileo and Scheiner, 78;
- Sunderland time signals, 278
- T.
- Talcott, zenith telescope designed by, 285
- Taurus, its position in the zodiac, 34
- Telegraph wires, their application in determining “local time,” 281
- Telepolariscope, The (Chap. XXX.), 441-453
- Telespectroscope, 426
- TELESCOPE, THE (Book II.), 55-172
- TELESCOPE, THE EQUATORIAL (Book V.), 293-368
- Telescope:—Various Methods of Mounting Large Telescopes (Chap. XX.), 293-327;
- refracting, 73-89;
- Galilean, 73;
- magnifying power of the telescope, 76, 79;
- Scheiner’s telescope, 78;
- focal length of early telescopes, 79;
- achromatic, 86;
- reflecting, 100-108;
- Gregory’s telescope, 101;
- Newton’s, 102;
- Cassegrain’s, 103;
- Sir W. Herschel’s 103, 108;
- Lord Rosse’s, De La Rue’s, Lassell’s, Foucault’s, Grubb’s, 108;
- eyepieces, 109-116;
- lenses and specula, 117-138;
- flint glass for lenses, 119;
- the “optick tube,” 139-151;
- the modern telescope, 152-172;
- magnifying and space penetrating power, 154, 155;
- illuminating power, 158;
- defining power, 160;
- reflecting and refracting compared, 170;
- permanence of optical qualities, 170;
- “telescopic sight,” 219;
- Sir Wm. Herschel’s at Slough, 294;
- Lord Rosse’s reflector, 294, 311, 312;
- refractor on alt-azimuth tripod, 296;
- simple equatorial mounting, 298;
- the German mounting, 299;
- Washington great equatorial, 309;
- English mounting, 310;
- forked mounting, 310;
- Greenwich equatorial, 310;
- Melbourne reflector, 312, 313;
- Paris reflector, 314;
- driving clock, 318;
- Newall’s refractor with spectroscope, 427;
- De La Rue’s, 459;
- Rutherfurd’s, 466;
- Newall’s, 459;
- Melbourne, 459
- Telescope, zenith (see Zenith Telescope)
- Temperature, its effect on the pendulum, 187, 193
- Terrestrial globe, 23
- Thales, his employment of the gnomon, 17
- Theodolite, 288
- Theodolite, astronomical, 287
- Thermometry, 374, 384
- Thermopile, 374
- Time; first reckoning of, 19;
- TIME AND SPACE MEASURERS (Book III.), 175-232
- Time, Greenwich (see Greenwich Time)
- Time, local, 281
- Time balls for distributing Greenwich time, 275
- Time signals, 278, 281, 283
- Timocharis, his observations in the Alexandrian museum, 19
- Tourmaline, in polarization of light, 443
- Transit Circle, The (Chap. XVI.), 233-252;
- Transit Clock, The (Chap. XVII.), 253-270
- Transit instrument, 171, 234, 236, 237;
- Transit of Venus, photographic observations, 475
- Trigonometrical tables, first construction of, 17
- Tropics, defined by Euclid, 12
- Trouvelot, ring of Saturn observed with the Washington refractor, 161
- Tube of the telescope, 139-151
- Tycho Brahe; astrolabe, 26;
- ecliptic astrolabe, 28;
- discoveries of, 37-52;
- biography of, 37;
- list of his instruments, 38;
- portrait, 39;
- catalogue of stars, 42;
- observatory (engraving), 43, 287;
- his solar system, 46;
- discovery of comet of 1677, 47;
- instruments for measuring distances and altitudes of stars, 51;
- clocks, 179, 184, 196;
- diagonal scale for measuring space, 213;
- mural quadrant, 233;
- transit circle, 284
- U.
- United States Naval Observatory, 341
- Uranus, as a telescopic object, 351
- Uraniberg, Tycho Brahe’s Observatory, 38
- V.
- Variable stars, 377
- Velocity of gases in sun-storms, 440
- Venice, ancient clock dials, 257
- Venus, in Ptolemy’s system, 3;
- Vibrations, ethereal, 373, 401, 410, 449, 450
- Vienna, refracting telescope, 141
- Villarceau, Yvon, driving clocks, 324
- Vega, heat of, 385
- Vernal equinox, its position in the constellations, 34
- Vernier, the, 214
- Vertical circle, Ertel’s, 290
- W.
- Walther, altitudes measured by, 36
- Washington Observatory; great refracting telescope, 302, 309;
- Watches, detached lever escapement for, 207
- Water clocks, 176
- Wave-lengths of light of solar gases, 440
- Westminster clock-tower, 277
- Wheatstone (Sir C.); “chronographic method” of transit observation, 259;
- apparatus for controlling clocks, 271
- Winlock (Prof.), photographs of the sun, 461
- Wires, cross, for circle reading, 212, 216;
- Wire micrometer, 221, 352
- Wolfius, correction of chromatic aberration in lenses, 89
- Wollaston (Dr.), lines in the solar spectrum, 391;
- Wyck (Henry de), clock made in 1364 by, 178
- Y.
- Ys of the transit instrument, 238, 284
- Years, first observation of, 5;
- determination of their length, 22
- Z.
- Zenith, zenith sector, zenith telescope, reflex zenith tube, at Greenwich, 285
- Zenith distances, measurement of, 51
- Zodiac, first defined, 8, 9;
- Zöllner’s astrophotometer, 379
- Zero of right ascension, 249
- Zinc in the sun, 419