Uranography. & Atlas

Front matter

-URANOGRAPHY;

OR,

A DESCRIPTION OF THE HEAVENS;

Preface

In offering to the public this brief description of the heavens, it has been my aim to make the work as simple and popular as possible. It is, of course, not to be expected that it can present much claim to novelty or originality. I shall be satisfied if the descriptions are true, and easily understood by the younger class of learners. The want of such a treatise has been felt while endeavouring to furnish popular instruction to the pupils of the High-School in this place. The Atlas of the Starry Heavens, published in 1839, in German, by J. J. Von Littrow, the distinguished Director of the Vienna Observatory, was used for some time as a basis of a course of oral instruction. The excellence of Littrow's Atlas, and of his method of describing the heavens, induced me to undertake the translation of the entire work. The maps have been re-engraved with English names of the constellations, and with such modifications as my experience had suggested. On comparing, however, Littrow's text with the most recent publications, particularly the Micrometric Mea sures of the celebrated Struve, I found that the progress

Ciii)

IV PREFACE.

of knowledge in the department of double stars has been so rapid of late, that it was necessary to write anew all that part which relates to this important portion of the sidereal heavens. This I have done in conformity with the most recent publications of Struve and Msedler. Another important modification of Littrow's method was required. He refers to another more extensive publication under the title of the " Wonders of the Heavens." I have extended this description of the heavens so as to embrace a portion of the interesting subjects treated of in that work. In doing so, I have written anew the chapters on the general description of the nebulae, and clusters of stars, chiefly from English authorities, among whom I mention with pleasure the papers of the elder and younger Herschel ; — the popular treatise of the latter, on astronomy, and Madam Somerville's work on the "Connexion of the Physical Sciences." In writing a treatise on Uranography, aiming to be simple and popular, I have thought it necessary to furnish, in each constellation, a method of finding the principal stars in the heavens by the process of lining. In these descriptions no novelty could be expected, and no other merit than that of simplicity has been aimed at. The position of the stars in the figures is adapted to this Atlas. The figures do not in all instances occupy the same place and size among the stars as in other Atlases and Globes. They rest, however, on the authority of the celebrated German astronomer Littrow. One important advantage will be found in this Atlas over most others ; the

PREFACE. V

faint outlines only of the figures are given, and the boundaries of the constellations. On a first glance at the maps, the stars are the prominent objects which strike the eye, and the pupil is not distracted in his efforts to learn the constellations, by missing in the heavens the objects made too conspicuous on the map. The number of the maps is so full that there is little distortion of the relative positions of the stars. It may seem almost preposterous in a work which attempts to give an epitome of the sublime discoveries of the Herschels and of Struve, that the fabulous history of the almost useless figures in the constellations should be interwoven ; they form, however, a part of the history of the progress of the human mind in one of its noblest studies, and as such must ever claim a place in a popular treatise like the present. While aiming to insert all that is requisite to aid trie steps of the beginner in astronomy, the claims and wants of the amateur have not been quite neglected. The text, in finer print, contains a selection of the most important and interesting double and multiple stars, nebulae and clusters, in each constellation, so described that any person having a telescope may select as types some which are suited to its capacity, and those who have no instrument may be furnished at once with such a description as the best instruments afford.

The work is simply descriptive of the heavens: to have attempted a treatise on practical astronomy, or the use of instruments, would have made the work too complex and voluminous. Those who wish to culti-

Yl PREFACE.

vate the study of practical astronomy may avail themselves of Gummere's Astronomy, (edition of 1842), Mason's Supplement to Olmsted's Astronomy, and Bowditch's Practical Navigator. Those who are not possessed of the British Nautical Almanac, will find a valuable auxiliary in Downes' United States Almanac or Complete Ephemeris, which contains numerous examples of useful computations in practical astronomy.

Philadelphia, April 23, 1844.

PART I. Sec. 1. — General Description of the Heavens

Page

Appearance of the Starry Heavens 11

Horizon, Zenith, Meridian 12

North Pole, Circumpolar Stars, Pole Star 13

Diurnal motion of the Heavens, Celestial Sphere 13

Sec. 2. — Preliminary Definitions.

Axis of the Heavens, Celestial Equator, Geometric Poles.. 14

Division of the Circle 14

Declination Circle, Vertical Line, Zenith and Nadir .... 15

Meridian of a place, Vertical Circle, Ecliptic 15

Equinoxes, Equinoctial Colure, Right Ascension 16

Declination 16

Sec. 3. — Constellations.

Origin of Constellations — their antiquity 17

Geography, Uranography 17

Littrow's Figures, Bayer's Designation of the Stars .... 18

Changes in their Magnitudes 19

Sec. 4. — Magnitudes of the Stars.

Division of Stars into Magnitudes 19

Herschel's Classification, Struve's do 20

(vii)

Vlll CONTENTS.

Sec. 5. — A more particular Description of the Starry Heavens.

Brilliancy of the Stars, Twinkling 20

Planets. Fixed Stars — their number 21

Description of Uranography 22

Use of a Celestial Atlas . . . . 22

Comparative Brilliancy of Stars of different Magnitudes. 23

Bode's Distribution of Stars 23

Harding's Atlas. Number of Telescopic Stars 24

Their tendency to appear in Groups 25

Sec. 6. — Double and Multiple Stars.

Tendency of Stars to appear in Pairs 25

Mitchel's and Herschel's Opinions of Double Stars 26

Herschel's Discoveries, Argelander's Investigations 26

Authors of Works on Double Stars 26

Herschel's Method of Computing their Orbits 27

Encke's Method, Maedler's Labours 27

Number of Double Stars — Physical Connexion 27

Ternary, Binary, Multiple Stars, &c 27

Stars Optically Double or Multiple 28

Revolutions of the Double Stars 28

Prevalence of Newtonian Gravity 28

Solar and Stellar Systems compared 28

Number of Double Stars above the 8th Magnitude 29

Struve's Number of Stellar Systems 29

Maedler's recent Estimate 30

Sec. 7. — Comets.

Reference to Section 22 30

Sec. 8. — Variable Stars.

Definition, Catalogue, Mira Ceti 31

Algol, and other Variable Stars 32

General Remarks, Causes of their Variations 34

New and Lost Stars 35 contents. ix

Sec. 9. — Nebula and Clusters of Stars.

Remarkable Groups, Milky- Way 36

Its Nature and Formation 37

Supposed Position of the Sun in the Milky- Way 38

Resolvable Nebulae, Globular Clusters 39

Irresolvable Nebulae, Annular do 40

Planetary and Stellar Nebulae, Nebulous Stars 41

Zodiacal Light supposed to be a Nebulosity 42

Clusters of Nebulae 42

Double Nebulae, Number of Nebulae 43

Their supposed Origin 43

General Remarks 44

Sec. 10. — Description or the Maps.

Maps of the Northern and Southern Hemispheres 45

Explanations of the Maps 46

Maps of the Northern Hemisphere, Plates III. to VII. . . 46

Maps of the Equatorial Regions, Plates VIII. and IX.. . 46

Maps of the Southern Hemisphere, Plates X, to XIV. . . 46

Map for Lining, Plate XV 47

Sec. 11. — Description of the Constellations.

Plate I.— -Northern Hemisphere.

Plate II. — Southern Hemisphere.

Plate III. — Constellations.

Ursa Minor — The Little Bear 47

Cepheus— The King 48

Draco — The Dragon 49

Lacerta — The Lizard 51

Honores Frederici — Frederick's Honours 52

Canes Venatici — The Grey-Hounds 52

Quadrans Mural is — The Mural Quadrant 52

Cygnus — The Swan 53

X CONTENTS.

Plate IV. — Constellations.

Ursa Major — The Great Bear 57

Custos Messium — The Guardian of the harvest 59

Camelopardalis — The Giraffe 59

Cassiopeia? — The Lady in her Chair 60

Leo Minor — The Little Lion 62

Lynx — The Lynx 62

Perseus et Caput Medusae — Perseus and Medusa? s Head,* 63

Tarandus — The Reindeer 65

Telescopium Hersehelii — HerscheVs Telescope 65

Plate V. — Constellations.

Pegasus — The Flying Horse 6Q

Andromeda — Andromeda 68

Triangula— The Triangles 69

Musca— The Fly 70

Pisces— The Fishes 70

Aries — The Bam 71

Plate VI. — Constellations.

Auriga — The Charioteer 73

Taurus— The Bull 74

Cancer— The Crab 76

Orion — Orion 78

Gemini— The Twins 81

Monoceros — The Unicorn 82

Canis Minor— The Little Dog 83

Plate VII. — Constellations.

Bootes — The Herdsman 84

Lyra— The Harp 86

Hercules — Hercules 88

Corona Borealis — The Northern Crown 90

Taurus Poniatowski — The Polish Bull 91

Leo Major — The Great Lion 99

CONTENTS. XI

Plate VIII. — Constellations.

Virgo — The Virgin 94

Coma Berenices — Berenice's Hair 100

Sextans— The Sextant 102

Plate IX. — Constellations.

Antinous — Antinous 103

Aquila— The Eagle 103

Libra— The Scales 104

Serpentarius vel Ophiuchus — The Serpent-bearer 105

Serpens — The Serpent 108

Delphinus— The Dolphin 109

Equiileus — The Little Horse 110

Scutum Sobieski — SobieskVs Shield 110

Turdus Solitarius — The Solitary Thrush Ill

Vulpecula et Anser — The Fox and Goose Ill

Sagitta— The Arrow 112

Plate X. — Constellations.

Sagittarius — The Archer 113

Scorpio — The Scorpion 114

Lupus— The Wolf 115

Ara— The Altar 116

Norma, vel Quadra Euclidis — The Rule 116

Telescopium — The Telescope 116

Corona Australis — The Southern Crown 116

Plate XL — Constellations.

Aquarius — The Water-bearer 117

Capricornus — The Goat 119

Piscis Australis — The Southern Fish 121

Globus JErostaticus — The Balloon 121

Microscopium — The Microscope 121

Grus— The Crane 121

Phosnix — The Arabian Bird . .• 121

Apparatus Sculptoris — The Sculptor's Tools 121

Indus — The Indian 122

Xll CONTENTS.

Plate XII. — Constellations.

Cetus— The Whale 129

Eridanus— The River Po . 124

Lepus— The Hare 125

Harpa Georgii — George's Harp 125

Sceptrum Brandenburgium — Sceptre of Brandenburgh.. 126

Apparatus C hemic us — Chemical .Apparatus 126

Machina Electrica — Electrical Machine 126

Caela Sculptoris — The Graver 126

Horologium — The Clock 127

Plate XIII. — Constellations.

Canis Major— The Great Dog 127

Argo Navis— The Ship Argo. 129

Columba— The Dove 130

Felis— The Cat 130

Equiileus Pictoris — The Painter's Easel 130

Officina Typographica — The Printing Press, 131

Pyxis Nautica — The Mariner's Compass 131

Plate XIV. — Constellations.

Hydra— The Water- Serpent 131

Crater— -The Cup 133

Centaurus — The Centaur 133

Coitus— The Crow 134

Antlia Pneumatica — The Air Pump 135

Robur Caroli — Charles' Oak 135

Crux— The Cross 135

Sec. 12. — The Calendar of Stars.

January 137

February 140

March 143

April 146

May 1 48

June 150

CONTENTS. Xlll

July 153

August > 156

September 159

October 162

November 164

December 166

Sec. 13.

Telescopic appearance of Double Stars 169

Sec. 14.

Portions of the Heavens rich in Stars 170

Clusters of Stars 172

Stellar Nebulae 174

Double Nebulae 177

Hollow Nebulae 178

Irresolvable and Planetary Nebulae 179

Other remarkable Nebulae 182

PART II. Sec. 1

General Description of the Solar System 185

Sec. 2.

Ptolemaic System 186

Sec. 3.

Copernican System 187

Ancient Opinion regarding the Figure of the Earth .... 188

Rotundity of the Earth demonstrated 188

Proof of the Earth's Diurnal Revolution ; 189 xiv contents.

Sec. 4.

Sec. 5.

Kepler's First Law 195

Definitions of the Ellipse 195

Kepler's Second Law 196

Illustration of Orbital Motion 197

Kepler's Third Law 197

Sec. 6.

Newtonian Theory of Gravitation 198

Principle of Gravitation 199

Extension of the Law of Gravity to the Stars 200

Sec. 7.

Figure of the Sun 202

Diameter and Revolution on its Axis 202

Opinions concerning the Nature of the Sun 203

Zodiacal Light — its Phenomena 203

Force of Gravity at the Surface of the Sun 204

Proper Motion of the Sun 205

Sec. 8.

Mercury — Rotation upon his Axis — his Distance 206

His Diameter 207

Distinction between Inferior and Superior Planets 207

Greatest Elongation of Mercury 207

Transits of Mercury 208

Density of Mercury 209

Force of Gravity at its Surface 210

Ancient Names of this Planet 210

Sec. 9.

Venus — its Distance, Rotation and Magnitude 211

Brilliancy of Venus ••••«•••••• 211

CONTENTS. XV

Great Vicissitudes of its Seasons 212

Transits of Venus 213

Sun's Parallax as deduced from these Transits 214

Effects of the small Eccentricity of its Orbit 214

Various Names of Venus 215

The Earth — its Distance from the Sun, and Diameter. . 215

Its Mass, Density and Figure 216

The Motions of the Earth 217

Day and Night 218

The Seasons 220

The Earth's Satellite 222

The Atmosphere 222

Cause of Winds 224

Change of Position of the Earth's Axis in the Heavens 225

Polar Stars 225

Second Variation in the Position of the Earth's Orbit. . 227

Definition of Perturbation 227

Third Variation of the Position of the Earth's Perihelion 227 Mythological Names of the Earth 228

General Remarks concerning Secondary Planets 228

Points of Resemblance with their Primaries 229

Equality of their Periods of Revolution and Rotation . . 230 Appearances of the Primary Planet viewed from its Secondaries 231

Force of Gravity upon the Secondary Planets 232

Its Revolution, Diameter, and apparent Motion 233

Libration in Longitude and Latitude 234

Phases of the Moon 235

Eclipses — Harvest Moon 237

XVI CONTENTS.

Appearances of the Heavens as seen from the Moon. . . 238

Eclipses at the Earth and at the Moon compared 240

Description of the Moon's Surface 241

Lunar Caverns — Crater-formed Elevations 242

Lunar Volcanoes — Central Mountains 243

Heights of Lunar Mountains 244

Mars — its Distance from the Sun — Diameter, &c 245

Inequality in the length of its Seasons 247

Its Days also unequal 248

Transits of inferior Planets seen from Mars 248

Mythological Names of this Planet 249

Vesta — its Diameter — Distance from the Sun, &c 250

Its Mythological History 250

Juno — its Place in the System, and its Orbit 251

Number of its Names among the Ancients 251

Ceres — its Description and Mythology 252

Pallas — its Place in the System 252

The great Inclination of its Orbit — its ancient History.. 253

General Remarks concerning the Asteroids 253

Their Periods of Revolution 255

Force of Gravity at their Surfaces very small 256

Jupiter — its Diameter, Period of Revolution, &c 257

Effects of the great centrifugal Force at its Equator. . . . 258

CONTENTS. XVH

Difference of the Seasons and of the length of Days. . . 258

Intensity of Light and Heat 259

Brightness of Jupiter 259

Telescopic Appearance 259

Jupiter's Satellites 261

Their Diameters 261

Apparent Motions of these Satellites 262

Their combined Light not equal to that of the Moon. . . 263

Mythological History of Jupiter 264

Saturn — its Distance from the Sun, Diameter, &c 265

Dimensions of its Rings 266

Telescopic appearance of the Planet 266

Rotation of the Rings 267

Cause of their elliptical Appearance 267

The Rings must be irregular Solids 268

Appearance of the Rings from the Planet itself ....... 269

Force of Gravity at the Surface of Saturn 270

Satellites of this Planet 271

Their Phases , 271

Their Eclipses 272

Their Periods of Revolution 273

The Mythology of Saturn 274

Herschel, or Uranus 275

Its Appearance to the unassisted Eye 275

Its mean Distance from the Sun — its Diameter, &c. . . . 275 The apparent Diameter of the Sun as seen from Uranus. 276 Amount of the Annual Parallax of the Fixed Stars for

Peculiarity of the Uranian System regarding the Satellites 277

Phases of the Satellites 277

Their Eclipses 278

XV111 CONTENTS.

Density of Uranus 278

Distances and Periods of Revolution of the Satellites. . 278

Mythological Account of Uranus 279

Comets — Origin of their Name 280

Number of Comets 280

Heads of Comets 281

Their nebulous Envelopes 282

The Tail of Comets 282

Apparent Lengths as seen from the Earth 283

Estimated real Lengths 284

Origin of the Envelope and Tail 284

Dissipation of the Substance of Comets 286

Popular Superstitions respecting Comets 286

Elements of the Orbits of Comets 288

Average Inclination of their Orbits 288

Probability that Comets move in Ellipses 289

Periodical Comets 290

Halley's Comet — its supposed Appearances 291

Its certain Appearances 292

Olbers' Comet — when discovered, &c 293

Encke's Comet — its observed Returns 294

Proof of a resisting Medium obtained by means of this

Comet 295

Gambart's Comet 296

Cause of its invisibility in 1839 296

Comets supposed to be periodical 297

Third Comet of 1843 298

Peculiarities of this Comet 299

Instability of the Position of its Orbit 300

Eclipses of the Moon — their Cause 301

Partial, total and central Eclipses 301

The Shadow of the Earth 302

CONTENTS. XIX

Duration of a Lunar Eclipse 302

Description of the Plate, Fig. 1 302

Difficulty of observing with exactness a Lunar Eclipse. 304

Eclipses of the Sun — how caused 305

Description of the Plate, Fig-. 2 305

Central, total and partial Eclipses 305

Annular Eclipses 306

Number of Eclipses in a Year 307

Sec. 24. — Tides.

High and low Tides— Spring Tides 308

Neap Tides 309

Tide Wave 310

Causes of the Neap Tides 312

Heights of Tides in various Places 315

Co-tidal Lines — Unit of Altitude 316

Establishment of a Port — Atmospheric Tides 317