Stargazing: Past and Present

by Sir Norman Lockyer

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];
  • invention of the gnomon ascribed to him, [16], [17];
  • meridian observations by, [25]
• 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];
  • engraving of Tycho Brahe’s, [26], [41];
  • his ecliptic astrolabe, [28]
• 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];
  • “Barlow lenses,” [89], [229]
• 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];
  • of mounting specula, [144];
  • automatic spectroscope, [397];
  • solar spectroscope, [428]
• Bunsen (Ernest de), on ancient astronomical observations, [6]
• Bunsen (Prof.) spectroscope, [396];
  • his burner, flame of, [407];
  • his work in spectrum analysis, [402], [412], [423]
• C.
• Calcium, line spectra of, [406], [418]
• Cambridge Observatory (U.S.), equatorial at, [339];
  • star spectroscope, [430];
  • transit circle, [247], [248], [251]
• 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];
  • early use of the gnomon, [16], [17]
• 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;
  • compensating balance, [207];
  • detached lever escapement, [208];
  • chronometer escapement fusee, [209]
• 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];
  • division into degrees, [8], [17], [21]
• Circles, great, defined by Euclid, [12]
• Circle Reading (Chap. XIV.), [211]-217;
  • Digges’ diagonal scale, [213];
  • the vernier, [214]
• Circle, Transit (see Transit Circle)
• Circle, meridian, at Cambridge (U.S.), [248];
  • mural, [241], [242]
• Circumpolar stars, [239]
• Clarke (Alvan), improvement in telescope lenses, [305];
  • great equatorial at Washington, [309], [319]
• 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];
  • spectrum analysis, [407], [408], [414], [416];
  • of stars, [165], [351], [433];
  • of waves of light, [420];
  • refrangibility of, [387]
• 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];
  • improvement in telescope lenses, [305];
  • equatorial refractor, [300];
  • driving clock for large telescopes, [321];
  • illuminating lamp for equatorial telescopes, [326]
• Copernicus, parallactic rules of, [41]
• Copernicus (lunar crater), [354]
• Cross wires for circle reading, [212], [216], [218];
  • in transit eyepiece, [234], [257]
• Crown-glass prisms, [83], [84];
  • lenses, [86], [88]
• 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];
  • improvements in polishing specula, [134];
  • celestial photography, [454], [459], [460], [464], [465], [475]
• 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];
  • correction of chromatic aberration, [89];
  • on manufacture of flint-glass discs, [118];
  • pancratic eyepiece, [113]
• 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];
  • early theories of its form, [6];
  • circumference measured by Posidonius, [8];
  • Euclid’s theory of its position, [12];
  • inclination of its axis, [14], [17];
  • size measured by Eratosthenes, [19];
  • position in Tycho Brahe’s system, [46]
• Eclipses, first observations of, [4];
  • eclipses of Jupiter’s moons;
  • eclipses, solar, photograph of, [474]
• Ecliptic, plane of the, [13], [14];
  • discovery of its inclination, [17];
  • inclination measured by Eratosthenes, [19]
• Ecliptic astrolabe of Tycho Brahe, [28]
• Edinburgh Observatory, clock arrangements at, [269];
  • standard clock, [272];
  • time signals, [278]
• 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];
  • his measurement of the earth, and inclination of the ecliptic, [19];
  • meridian circle invented by, [20]
• 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;
  • ancient, [177];
  • anchor, [197];
  • Graham’s, [199];
  • Mudge’s, [200];
  • Greenwich clock, [203];
  • detached lever, [208];
  • chronometer escapement, [209]
• Ethereal vibrations, [373], [401], [410], [420], [449], [450]
• Euclid, his observations of the stars, [8], [9], [10];
  • of great circles, horizon, meridian and tropics, [11], [12];
  • theory of the earth’s position, [12];
  • pole star, [14]
• 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];
  • Ramsden’s, Dollond’s, [112];
  • erecting or “day eyepiece,” [112];
  • Dawes’s solar eyepiece, [114];
  • magnifying power of, [116]
• 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];
  • lenses, [86], [170]
• Flint-glass, improvements in the manufacture of discs of, [118], [119], [305]
• Focal length of telescopes, [82], [458];
  • of lenses, [62], [63];
  • of convex mirrors, [94]
• Foucault; his reflecting telescope, [108];
  • improvement of specula, [117];
  • mode of polishing specula, [134], [136];
  • mounting of his telescope, [311];
  • governor of driving clock for large telescopes, [323];
  • siderostat, [343];
  • spectrum analysis, [410];
  • heliostat, [424]
• Fraunhofer; manufacture of flint-glass discs, [118];
  • large telescopes, [303];
  • lines in the solar spectrum, [392];
  • spectrum analysis, [402], [410], [422], [425], [432], [438]
• Frederick II. of Denmark, his patronage of Tycho Brahe, [38]
• Fusee for chronometers, [209]
• G.
• Galileo; his telescopes, [73], [78];
  • • their magnifying power, [77];
  • the pendulum, [183], [184]
• 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];
  • improvements in, [18], [175]
• 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];
  • transit room, [251], [257];
  • meridian of, [252];
  • chronograph, [260]-264;
  • computing room, [267];
  • standard sidereal clock, [267];
  • mean solar time clock, [268];
  • standard clock, [274];
  • pendulum, [188];
  • reflex zenith tube, [286];
  • alt-azimuth, [290];
  • equatorial, [310];
  • thermopile, [384];
  • photoheliograph, [469]
• “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];
  • adjustment of object-glasses, [141];
  • Cassegrainian and Newtonian reflectors, [102], [108], [301], [303];
  • great Melbourne equatorial telescope, [108], [314], [315], [317], [324], [327];
    • mode of mounting its speculum, [145]-149;
  • automatic spectroscope, [397];
  • solar spectroscope, [428]
• 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];
  • table of reflective powers, [169];
  • star magnitudes, [381]
• Herschel, Sir William, his reflecting telescopes, [103], [108];
  • his mode of polishing specula, [129];
  • great telescope at Slough, [169], [294]
• Herschel-Browning direct-vision prism, [400]
• Hipparchus, trigonometrical tables constructed by, [17];
  • discoveries of, [25]-35;
  • his measurement of space, [213]
• Hittorf, spectrum analysis, [413]
• Holmes (N. J.), his proposal of the electric time-gun, [278]
• Hooke, improvement in clock escapements, [196];
  • micrometer, [221], [222];
  • zenith sector invented by, [285];
  • siderostat suggested by, [343]
• 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];
  • eyepiece, [110], [116], [212];
  • application of the pendulum to clocks, [183];
  • his measurements of space, [219], [223], [343];
  • polarized light, [442]
• Hydrogen in the sun, [435]
• I.
• Iceland spar crystals; double refraction by, [226], [228];
  • polarization of light, [442], [445], [447], [449], [450]
• 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];
  • in Tycho Brahe’s, [46];
  • as a telescopic object, [351];
  • photographs of, [465], [466]
• 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];
  • spectrum analysis, [402], [403], [412], [422], [428]
• 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];
  • production, polishing, and mounting metallic specula, [121], [132], [144]
• Latitude; observations of Posidonius, [8];
  • parallels of, [23]
• Lattice-work for tubes of telescopes, [172]
• Lenses; action of, [55], [58], [85];
  • concave and convex, [61], [71], [75];
  • amount of colour produced by, [81];
  • achromatic, [84];
  • Hall and Dollond’s experiments, [85];
  • correction for colour, [87];
  • correction for aberration in eyepieces, [109], [116];
  • production of, [117]
• 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];
  • as determined by Hipparchus and Tycho Brahe, [44];
  • determined by clock and transit instrument, [280];
  • expressed in degrees and time, [280]
• 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];
  • in Tycho Brahe’s, [46];
  • as a telescopic object, [350]
• 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];
  • composition and production of specula, [120], [121], [129];
  • view of optical part, [143];
  • mode of mounting speculum, [144]-149;
  • photographs of the moon, [459]
• Mercurial pendulum, [187], [188], [192]
• Mercury, in Ptolemy’s system, [3];
  • in Tycho Brahe’s, [46];
  • as a telescopic object, [350]
• 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];
  • cost of large object-glasses, [172];
  • large telescopes, [303]
• Metallic specula, [120], [171]
• Meton, meridian observations by, [25]
• Meudon Observatory, solar photography at, [470]
• Micrometer, The (Chap. XV.), [218]-232;
  • wire micrometer, [221], [352];
  • heliometer, [224];
  • double image, [229];
  • position, [353];
    • measurements made by, [355], [359]-366, [368]
• 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];
  • with spectroscope, [427];
  • flint-glass discs for, [119];
  • production of discs for object-glass, [128];
  • photographs of the moon, [459]
• Newcastle, time signals, [278]
• Newton (Sir Isaac), on refracting telescopes, [82];
  • his reflecting telescope, [101], [102];
  • use of pitch in polishing specula, [128];
  • refrangibility of light, [387];
  • polarized light, [442]
• Newtonian reflector, [149];
  • view of optical part, [143];
  • effective light, [169];
  • Grubb’s form, [303];
  • Browning’s form, [304];
  • mounting of, [310]
• Nicols’ prism, [115];
  • measurement of the light of stars, [380];
  • polarization of light, [443], [447], [448], [449], [450]
• North pole, diagram illustrating how it is found, [249], [251]
• O.
• Object-glasses, production of, [118], [119];
  • correction of colour, [88];
  • correction for spherical aberration, [126];
  • mode of polishing, [128];
  • mode of centring, [140];
  • illustrations of defective adjustment, [141];
  • adjustment of, [163];
  • its perfection in modern telescopes, [166], [305];
  • cost of production, [172];
  • divided, for duplication of image, [225]
• 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];
  • long and short sight, [69], [71]
• 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];
  • Orion and the neighbouring constellations, [156];
  • nebula of, [157], [158];
  • stars in, a test for power of telescopes, [164]-166;
  • facilities for observing, [164]
• P.
• Parallactic rules, [51];
  • used by Ptolemy, [35];
  • by Tycho Brahe, [38], [41]
• Parallax of the moon, observed by Ptolemy, [35]
• Paris Observatory, reflecting equatorial telescope, [314], [315], [337];
  • siderostat, [344];
  • photoheliograph, [469]
• 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];
  • first observations of conjunction, [4], [5];
  • motions observed by Autolycus, [9];
  • in Tycho Brahe’s system, [46];
  • Saturn seen with object-glasses of 3¾ and 26 inches, [160], [161];
  • as telescopic objects, [350];
  • photographs of, [465]
• 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];
  • observations of Euclid, [10], [14];
  • its position, [238]
• Polishing lenses and specula, [128], [171];
  • Lord Rosse’s polishing machine, [131];
  • Mr. Lassell’s, [132]
• 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];
  • crown and flint-glass, [83], [84];
  • water, [85];
  • doubly refracting, for the micrometer, [226];
  • direct vision, [400];
  • in the spectroscope, [393]-400;
  • object-glass prism, [426]
• Ptolemy, the Heavens according to, [3];
  • trigonometrical tables, [17];
  • sun’s altitude, [21];
  • his discoveries, [35];
  • parallax of the moon, [35];
  • his measurement of time, [36];
  • parallactic rules, [38], [51]
• 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];
  • measured by Hipparchus, [44];
  • by Tycho Brahe, [45]
• Ring micrometer, [368]
• Robinson (Dr.),
  • specula of Melbourne telescope, [129];
  • apertures of object-glasses, [168]
• 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];
  • composition of reflector, [120];
    • production of metallic specula, [121], [131];
    • nebula of Orion as seen by his reflector, [157], [158];
    • illuminating power of his telescope, [159];
    • effective light, [169];
  • thermopile observations, [384]
• 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];
  • in Tycho Brahe’s, [46];
  • as seen with a 3¾ inch and 26 inch object-glass, [160], [161];
  • as a telescopic object, [351];
  • mode of measuring its rings, [357];
  • photographs of, [465], [466]
• 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];
  • colours of stars, [351];
  • star magnitudes, [381]
• Smyth (Prof. Piazzi), on the pyramids as astronomical instruments, [6];
  • position of the vernal equinox, [34];
  • clock arrangements at Edinburgh Observatory, [269]
• 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];
  • photographs of, [479], [480]
• Solar time, [253], [255]
• Solstices, first observations of the, [15], [16], [17], [22]
• Southing of stars, [234]
• SPACE MEASURERS (Book III.), [135]-232;
  • circle reading, [211];
  • Digges’ diagonal scale, [213];
  • the vernier, [214];
  • micrometers, [218]
• Space-penetrating power of the telescope, [154];
  • stars in Orion, a test of, [165]
• Spectroscope, construction of the, [393]-400;
  • automatic, [397];
  • arranged for showing absorption, [409];
  • attached to Newall’s refractor, [427];
  • solar, Browning’s and Grubb’s forms, [428]
• 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];
  • casting, annealing, [121];
  • curvature, [122];
  • grinding, [127];
  • polishing, [128];
  • silvering, [137];
  • mounting, [142], [169], [172];
  • effective light, [169];
  • repolishing, [171];
  • cost as compared with object-glasses, [172]
• Spherical aberration, [87];
  • diagram illustrating, [104], [105];
  • its correction in eyepieces, [109], [111];
  • of specula, [123], [124]
• 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];
  • variable, [377]-[385]
• 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];
  • spectrum analysis, [402], [410]
• Stone, thermopile at Greenwich, [384]
• Strontium in the sun, [419]
• Struve, transit instrument, [285];
  • double stars, [362];
  • star magnitudes, [381]
• 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];
    • and the Scarphie, [19], [20];
  • 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];
  • examined by the position micrometer, [358];
  • spectra of, [415], [435]
• 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;
    • Huyghen’s eyepiece, [110];
    • Ramsden’s eyepiece, [112];
    • magnifying power of eyepieces, [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];
  • early measurements, [36], [44], [175];
  • modern measurement of, [253];
  • sidereal, solar, and mean, [254], [256]
• 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;
  • system of wires in eyepiece, [220];
  • at Greenwich and Cambridge (U.S.), [247], [248], [251];
  • mode of using, [253], [284]
• Transit Clock, The (Chap. XVII.), [253]-[270]
• Transit instrument, [171], [234], [236], [237];
  • mode of using, [253];
  • Römer’s, [284];
  • Struve’s, [285]
• 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];
  • in Tycho Brahe’s, [46];
  • employed by Tycho Brahe in determining longitude, [44];
  • as a telescopic object, [350];
  • transit of, instrument used in the expedition of 1874, [236];
  • photographic observations, [475]
• 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];
  • flint glass discs, [119];
  • ring of Saturn seen through it, [161]
• 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];
  • system of wires in a transit eyepiece, [220], [234], [257];
  • in eyepiece of Greenwich transit circle, [246];
  • wires of the transit instrument, [234]
• Wire micrometer, [221], [352]
• Wolfius, correction of chromatic aberration in lenses, [89]
• Wollaston (Dr.), lines in the solar spectrum, [391];
  • spectrum analysis, [402], [422]
• 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];
  • observations of Euclid, [11], [12];
    • of Denderah, [7]
• Zöllner’s astrophotometer, [379]
• Zero of right ascension, [249]
• Zinc in the sun, [419]

THE END.

LONDON: R. CLAY, SONS, AND TAYLOR, BREAD STREET HILL, E.C.

TRANSCRIBER'S NOTES

1. Silently corrected typographical errors.
2. Retained anachronistic and non-standard spellings as printed.