THE SOUTH-EAST DOME WITH THE SHUTTER OPEN.
Gravitation thus appears, indeed, to be the Bond of the Universe, yet it leaves us with several weighty problems. The observation of the positions of stars shows that though we call them fixed they really have motions of their own. Of these motions, a great part consists of a drift away from one portion of the heavens towards a point diametrically opposite to it, a drift such as must be due, not to a true motion of the individual stars, but to a motion through space of our sun and its attendant system. The elder Herschel was the first to discover this mysterious solar motion. Sir George Airy and Mr. Edwin Dunkin, for forty-six years a member of the Greenwich staff, and from 1881-1884 the Chief Assistant, contributed important determinations of its direction.
What is the cause of this motion, what is the law of this motion, is at present beyond our power to find out. Many years ago a German astronomer made the random suggestion that possibly we were revolving in an orbit round the Pleiades as a centre. The suggestion was entirely baseless, but unfortunately has found its way into many popular works, and still sometimes is brought forward as if it were one of the established truths of astronomy. We can at present only say that this solar motion is a mystery.
There is a greater mystery still. The stars have their own individual motions, and in the case of a few these are of the most amazing swiftness. The earth in its motion round the sun travels nearly nineteen miles in a second, say one thousand times faster than the quickest rush of an express train. The sun's rate of motion is probably not quite so swift, but Arcturus, a sun far larger than our own, has a pace some twenty times as swift as the orbital motion of the earth. This is not a motion that we can conceive of as being brought about by gravitation, for if there were some unseen body so vast as to draw Arcturus with this swiftness, other stars too would be hurtling across the sky as quickly. Such 'runaway stars' afford a problem to which we have as yet no key, and, like Job of old, we are speechless when the question comes to us from heaven, 'Canst thou guide Arcturus and his sons?'
It will be seen then that, fundamentally, Greenwich Observatory was founded and has been maintained for distinctly practical purposes, chiefly for the improvement of the eminently practical science of navigation. Other inquiries relating to navigation, as, for instance, terrestrial magnetism and meteorology, have been added since. The pursuit of these objects has of necessity meant that the Observatory was equipped with powerful and accurate instruments, and the possession of these again has led to their use in fields which lay outside the domain of the purely utilitarian, fields from which the only harvest that could be reaped was that of the increase of our knowledge. So we have been led step by step from the mere desire to help the mariner to find his way across the trackless ocean, to the establishment of the secret law which rules the movements of every body of the universe, till at length we stand face to face with the mysteries of vast systems in the making, with the intimate structure of the stellar universe, with the apparently aimless, causeless wanderings of vast suns in lightning flight; with problems that we cannot solve, nor hope to solve, yet cannot cease from attempting, problems to which the only answer we can give is the confession of the magicians of Egypt—'This is the finger of God.'
INDEX
Aberration of light, [79]
Adams, John C., his discovery of Neptune, [217]
Adhara, [183]
Airy, George Biddell, seventh Astronomer Royal, his early life, [102];
his work at Cambridge, [105];
comes to Greenwich, [105];
his relations with the Visitors, [106];
his autobiography, [108];
his character, [111];
his labours, [113];
attacks on, [114];
his distinctions, [118];
his resignation, [119];
his death, [120];
anecdote of, [142];
his conduct re Adams, [217];
his water telescope, [304]
Alderamin, [183]
Almagest, [185]
Almanac making, [29]
Alpha Aquilæ, telescope for, [303]
—— Cygni, telescope for, [303]
Altazimuth the, [114];
description and work of, [207], et seq.
Altazimuth Department, [205], et seq.
American time, [153]
Andromeda nebula, [301]
Anemometer, use of, [238];
trace of, [242]
Angström, [268]
Anson, Commodore, [17]
Apparent time, [152]
Arcturus, motion of, [315]
Argelander, star catalogue of, [287]
Art of Dialling, the, [28]
Assistants, position of the, [98], [100], [117], [137]
Astrographic chart, [128]
—— Department, [284], et seq.
—— dome, [128]
—— telescope, [289], et seq.
Astronomers Royal, the, [25]
Astrophysical researches, [282]
Auroræ, [281]
Automatic register, [241]
Axis of the earth, precession of, [184]
Ball, Time, [162]
Barometer, use of the, [192], [233]
Battery basement, [161]
Beaufort, Captain, [107]
Bessel quoted, [266]
Betelgeuse, [184]
Birkenhead, wreck of the, [180]
Bliss, Nathaniel, fourth Astronomer Royal, history of, [82]
Bradley, James, third Astronomer Royal, his life, [73];
his ordination, [74];
Vicar of Bridstow, [74];
Savilian Professor of Astronomy, [75];
discovers Aberration of Light, [75], et seq.;
becomes Astronomer Royal, [79];
labours of, [80];
character of, [81]
Bradley's transit room, [128]
Brinkley, Dr., [303]
British Mariner's Guide, the, [90]
Bunsen, [268]
Buys Ballot's law, [237]
Canadian time, [153]
Castor, [74], [306]
Catalogues, star, [182], [185], et seq., [198], [284]
Cepheus, [183]
Charles II., warrants of, [39], [40]
Christie, W. H. M., eighth Astronomer Royal, work of, [120]
Chromosphere of the sun, [268]
Chronograph, the, [157]
—— room, [126]
Chronometer business, [101], [107]
Chronometers, Harrison's improvements in, [165], et seq.;
tests of, [169];
'runs' of, [173];
romance of, [178]
Circle Department, [181], et seq.
Clock, Astrographic driving, [290];
driving 28-inch telescope, [312]
Clocks, standard, [160]
Columbus, aim of voyage of, [18]
Comet, appearance of a, [28]
—— Wells, [280]
Comets, observation of, [224];
spectra of, [280]
Commutator, the, [162]
Comte, assertion of, [267]
Constant of Aberration, [79]
Cook, Captain, work of, [170]
Copper, use of in Observatory, [245]
Corona of the sun, [264]
Crabtree, James, [31]
Crosthwait, Joseph, [57]
Dallmeyer telescope, [252]
Declination, [186], et seq.
Denebola, [184]
Distances of planets, [223];
of sun, [224]
Double-Star Department, [303], et seq.
Double Stars, [306]
Dublin time, [155]
Dunkin, Edwin, [315]
Earth, the, movements of, [201]
Eclipses of the moon, [216];
of the sun, July 25, 1748...85;
other eclipses of the sun, [263], et seq.
Electric Railway, influence of, [249]
Equation of Time, the, [29], [151]
Equatorial, Shuckburgh's, [101]
——, the great 28-inch, [221]
——, the Merz, 123/4-inch, [114]
——, 28-inch, driving clock of, [309];
use of, [313]
——, clock-driven, [74]
Eros, discovery of, [223];
photographs of, [298]
Errors in observations, noting of, [199], et seq.
Evaporation, [241]
Faculæ of the sun, [257]
Flamsteed, John, his report on Saint-Pierre's proposal, [23], [32];
appointed first Astronomer Royal, [23], [34];
his autobiography, [26];
his studies, [29];
his almanac, [29];
sent to London, [30];
enters Jesus College, Cambridge, [31];
completes his observatory, [31];
acquaintance with Newton, [31];
takes his degree, [32];
his work, [34];
warrant for his salary, [39];
position of, [42];
his ordination, [45];
his pupils, [45];
his trouble with Newton, [46], et seq.;
his catalogue, [53];
his letter to Sharp, [54];
his death, [56];
his labours, [57]
Flamsteed House, [126]
Fraunhofer mounting, [310]
French time, [155]
Galileo, his discovery of Jupiter's satellites, [19]
Gamma Draconis, [75], [304]
—— Virginis, [306]
Gascoigne, William, [31]
Gemma Frisius, plan of, [22]
George of Denmark, Prince, [50]
German mounting, [276], [310]
Gould, Dr., [287]
Graham, [166]
Gravitation, the bond of the universe, [313]
Great comet of 1882, the, [280], [288]
Greatrackes, Valentine, [29]
Green, Charles, [91]
Greenwich time, [153];
distribution of, [163]
Halley, Edmund, his life, [60];
his early work, [60];
his catalogue of stars, [63];
elected F.R.S., [63];
his work on Kepler's laws, [64];
becomes captain, [65];
Savilian Professor of Geometry, [66];
Astronomer Royal, [66];
observations on saros of the moon, [67];
pressed by Newton, [68];
his death, [68];
his services to science, [68];
his pay, [70];
nominates his successor, [73];
his transit instrument, [73]
Halley's comet, [225]
Harrison, James, timekeepers of, [86], [91], [93], [165]
Heineken, Rev. N. S., [59]
Heineken quadrant, [59]
Heliographic Department, [251], et seq.
Herschel, Caroline, [57]
Hipparchus, catalogue of, [185]
Hodgson, Mr., [50]
Hooke, Robert, [75], [206]
Horrox, Jeremiah, [31]
Huggins, Sir W., his use of spectroscope, [268]
Inscription, an, [126]
International Photographic Survey, [296]
Ireis, [224]
Iron quadrant, [73]
Isobars, [237]
Jupiter, satellites of, [19], [296];
atmosphere of, [279]
Keill, John, [74]
Kendall, Larcum, [166]
Kepler, laws of, [64]
Kew, photo-heliograph, the, [252]
Kinnebrook, David, [176]
Kirchhoff's use of spectroscope, [267]
Latitude, finding the, [18]
Ledgers, chronometer, romance of, [176]
Leverrier, his discovery of Neptune, [217]
Libraries, [132]
Linacre, G., [28]
Lindsay, Thomas, quoted, [204]
Litchford, W., [28]
Local apparent time, [22]
Longitude, finding the, [18];
at sea, problem of, [86];
determination of, [173]
Longitude nought, [148]
Lower computing room, [128]
Lunars, method of, [86]
Magnetic Department, work of, [133];
description of, [228], et seq.
Magnetic inclination and declination, [246]
—— needles, movements of, [247], [262]
—— observatory, [132]
—— pavilion, [245]
—— storms, [248], [262]
Mars, distance of, [223];
atmosphere of, [279];
satellites of, [296]
Maskelyne, Nevil, fifth Astronomer Royal, [85];
practical work of, [86];
Astronomer Royal, [91];
his work, [92];
his publications, [92];
his observations and work, [92], et seq.;
his death, [94];
his character, [97];
recommends his successor, [97];
his mural circle, [101]
Mean solar clock, [160]
Mean time, [152]
Meldrum, Dr., on sun spots, [263]
Meridian, the, [149]
Merz telescope, [279]
Meteorological Department, work of, [133];
description of, [228], et seq.
Micrometers, use of, [309]
Microscopes, use of, [188]
Milky Way, [288]
Miller, Professor, [268]
Milne, Professor, on earth movements, [201]
Minor planets, [222]
Molyneux, Samuel, [75]
Moon, observation of the, [212], et seq.;
eclipses of, [266]
Moore, Sir Jonas, [30];
death of, [42]
Morin, [33]
Mounting telescopes, modes of, [310]
Mudge, Thomas, [94]
Mural arc, 7-feet, [46]
Mural circles, [101], [196]
Names of stars, origin of, [183]
Nares, Sir George, [170]
Nautical Almanac, the, [22], [23], [92]
Navigation, state of primitive, [17]
Neptune, discovery of, [217];
atmosphere of, [280];
satellite of, [298]
New altazimuth, the, [132], [210]
New Observatory, the, [136], [275]
New stars, [268]
Newcomb, Professor, on growth of Observatory, [124];
on Greenwich observations, [207]
Newton, Sir I., his absent-mindedness, [31];
his trouble with Flamsteed, [46], et seq.;
on Kepler's laws, [65];
his Principia, [65];
his pressure on Halley, [68];
his discovery of gravitation, [206]
North terrace, the, [126]
Northumberland equatorial, [218]
Nutation of the earth, [80]
Observation, modes of, [156], [176], [188];
by reflection, [196];
of comets, [224]
Observatory, Greenwich, work of, [13];
foundation of, [23];
warrant for building, [40];
position of, [41];
foundation stone laid, [42];
condition of, [79];
enlargement of, [112];
recent extensions of, [120];
description of, [124], et seq.;
staff of, [137];
work of, [139], et seq.;
visitors to, [175];
new altazimuth building, [211];
magnet house, [228];
magnetic pavilion, [245];
new Observatory, [275];
future of, [283];
reflex zenith room, [304];
objects of, [316]
Occultations by the moon, [212], et seq.
Octagon room, [125], [238], [242]
Oldenburg, Mr., [30]
Orion nebula, [268], [301]
Parallax of stars, [303]
Paramour, the, [65]
Paris, conference at, [288]
——, noon at, [151]
Philip III., offer of, [19]
Photographic registration, [244], [247], [252], [255];
refractors, [288]
Photographs, star, [290]
Photo-heliographs, [252], et seq., [279]
Piazzi, discovery of, [222]
Pleiades, the, [301]
Polar plumes of the corona, [264]
Polaris, [188]
Pole-star, variation of, [184]
Pond, John, sixth Astronomer Royal, his life, [97];
his reign, [98];
his salary, [98];
his assistants, [98];
his observations, [99];
censured by Visitors, [99];
his observations of stars, [303]
Pound, James, [73]
Precession of earth's axis, [184]
Principia, publication of, [65]
Proctor, R. A., attack of, [116]
Ptolemy, Claudius, catalogue of, [185]
Publication, the problem of, [48], [92]
Quadrant, Heineken, [59]
——, the iron, [73]
Railway time, [152]
Rain gauge, [238]
Record rooms, [132]
Reflection, observation by, [196]
Reflex zenith room, [304]
—— —— tube, [131]
Refraction, effects of, [194]
Right ascension, [186], et seq.
Roberts, Dr. Isaac, [301]
Römer, discovery of, [78]
Rosse, Lord, [268]
Royal Society and Flamsteed, [46], et seq.
Saint-Pierre, Le Sieur de, proposal of, [23], [32]
Sappho, [224]
Saros of the moon, [67]
Satellites, discovery of, [296]
Saturn, atmosphere of, [279];
satellites of, [296]
Schaeberle's comet, [280]
Schedar, [184]
Schiehallion, attraction of, [94]
Schönfeld, [287]
Scotchmen, anecdote of, [146]
Sharp, Abraham, [46]
Sheepshanks, Rev. James, on Airy, [107]
Shuckburgh equatorial, [309]
Sidereal clock, [160]
Sirius, [287]
Sloane, Dr., [50]
'Smith, Mr.,' his chronometer, [179]
Solar photographs, [257]
—— storms, [261], [282]
Sound waves, [271]
South, Sir James, [105], [114]
South-east equatorial, the, [132], [221]
Spectroscope, use of, [267]
Spectroscopic Department, [266], et seq.
Spots, sun, [251], et seq., [281]
Staff of Observatory, [137];
work of, [139], et seq.
Standard time, [21]
Stars, observations of, [156], [176], [188];
origin of names of, [183];
movements of, [187];
catalogues of, [198], [284], et seq.;
composition of, [268], et seq.;
colour of, [271];
classes of, [287];
census of, [287];
photographs of, [288], et seq.;
motions of, [303], [315]
Story, Mr. A. M., [97]
Sun, distance of the, [74], [224];
spots on, [251], et seq., [281];
eclipses of, [263], et seq.;
chromosphere of, [268];
motions of, [315]
Sunshine recorder, [238]
Swiss time, [155]
Tebb, Mr. W., [58]
Tebbutt's comet, [280]
Telescope, the great transit, [156]
——, 28-inch, [275]
——, astrographic, [289]
——, Shuckburgh, [309]
——, Thompson, [256], [279], [296]
Thalèn, [268]
Thermometer, use of, [192], [234]
Thome, Dr., [287]
Thompson photo-heliograph, [256], [279], [296]
Time ball, [162]
—— Department, the, [146], et seq.
—— desk, [161]
——, foreign, [153]
—— signals, [162]
—— standard, [21]
Transit, Halley's, [73]
Transit circle, the, [114];
mode of observation with, [188], et seq.
Transit circle, Troughton's, [98]
—— Department, [181], et seq.
—— observations, number of, [140]
—— pavilion, [126], [175]
—— room, [128], [147]
Troughton's transit circle, [98]
Uranus, discovery of, [217];
atmosphere of, [279];
satellites of, [296]
Vanes, use of, [238]
Venus, distance of, [223]
Victoria, [224]
Visitors, the Board of, [53];
censures Pond, [99];
work of, [106];
constitution of, [144]
Visitors to Observatory, [175]
Warrant for Flamsteed's salary, [39]
Water telescope, [304]
Weather predictions, [229], et seq.
Winds, study of, [237]
Witt, Herr, discovery of, [223]
Working Catalogue, the, [142]
Zenith sector, [82], [305]
—— tube, [75], [305]
Zeta Ursæ Majoris, [306]
Zubeneschamal, [184]