Comets visible in the daytime.-Breaking up of a Comet into parts.-

Instance of Biela's Comet.-Liais's observations of Comet iii. 1860.-Comets

probably self-luminous.-Existence of phases doubtful.-Comets with Plane-

tary discs. Phenomena connected with the tails of Comets.-Usually in the

direction of the radius vector.-Secondary Tails.-Vibration sometimes

noticed in tails.-Olbers's hypothesis.-Transits of Comets across the Sun's

disc. Variation in the appearance of Comets exemplified in the case of that

of 1769.-Transits of Comets across the Sun.

395-414

CHAPTER II.

PERIODIC COMETS.

...

Periodic Comets conveniently divided into three classes.-Comets in Class I.—

Encke's Comet.-The resisting medium.-Table of periods of revolution.—

Tempel's Second Comet.-Winnecke's Comet.-Brorsen's Comet.-Tempel's

First Comet.-Swift's Comet.-Barnard's Comet.-D'Arrest's Comet. —

Finlay's Comet.-Wolf's Comet. -Faye's Comet. - Denning's Comet.

Mechain's Comet of 1790.-Now known as Tuttle's Comet.-Biela's Comet.

-Di Vico's Comet of 1844.-List of Comets presumed to be of short periods

but only once observed.-Comets in Class II.-Westphal's Comet.-Pons's

Comet of 1812.-Di Vico's Comet of 1846.-Olbers's Comet of 1815.-Brorsen's

Comet of 1847.-Halley's Comet.-Of special interest.-Résumé of Halley's

labours.—Its return in 1759.-Its return in 1835.-Its history prior to 1531

traced by Hind.-Comets in Class III not requiring detailed notice,

CHAPTER III.

REMARKABLE COMETS.

415-45

The Great Comet of 1811.-The Great Comet of 1843.-The Great Comet of 1858.

-The Comet of 1860 (iii.).-The Great Comet of 1861.-The Comet of

1862 (iii.).—The Comet of 1864 (ii.)—The Comet of 1874 (iii.).—The Comet

of 1882 (iii.).

446-81

CHAPTER IV.

CERTAIN STATISTICAL INFORMATION RELATING TO COMETS.

Dimensions of the Nuclei of Comets.-Of the Comæ.-Comets contract and expand

on approaching to, and receding from, the Sun.-Exemplified by Encke's in

1838.-Lengths of the Tails of Comets.-Dimensions of Cometary orbits.—

Periods of Comets.-Number of Comets recorded.—Duration of visibility of

Comets. Unknown Comet found recorded on a photograph of the Eclipse of

the Sun of May 17, 1882.

482-86

CHAPTER V.

HISTORICAL NOTICES.

Opinions of the Ancients on the nature of Comets.-Superstitious notions

associated with them.-Extracts from ancient Chronicles.-Pope Calixtus III.

and the Comet of 1456.-Extracts from the writings of English authors of the

16th and 17th centuries.-Napoleon and the Comet of 1769.—Supposed

allusions in the Bible to Comets. -Conclusion.
487-90

CHAPTER VI.

DETERMINATION OF THE ELEMENTS OF THE ORBIT OF A COMET

BY A GRAPHICAL PROCESS.

SECTION 1.-Preliminary.

...

...

491-4

...

494 5

SECTION 2.-On the proportioning of the Areas in the different Segments of the

Projection........

SECTION 3.-The Latitudes and the Inclination of the Plane of the Orbit.

SECTION 4.-To find a Parabola having its Focus at S and which shall coincide with

two Points of the Orbit ...

496-7

498

498 9

SECTION 5.-The Measurement of the Areas in a Parabola

SECTION 6.-The Relations between the Time-intervals and the Longitude

Lines

...

SECTION 7.-Checks available, derived from certain properties of Parabolic

Orbits.

A CATALOGUE OF COMETS RECORDED, BUT NOT WITH SUFFICIENT

PRECISION TO ENABLE THEIR ORBITS TO BE CATALOGUED. 550-88

Classification of the subject.-Aerolites.-Summary of the researches of Berzelius,

Rammelsberg, and others.-Celebrated Aerolites.-Summary of facts.--

Catalogue of Meteoric Stones. -Arago's Table of Apparitions.- The Aerolite

of 1492.—Of 1627.—Of 1795.-The Meteoric Shower of 1803.-The Aërolite of

1876 (Rowton).-The Aerolite of 1881 Middlesborough).-The Aerolite of

1887 (Soko Banja).

589-98

CHAPTER II.

FIREBALLS.

General Description of them.-Fireball of Nov. 12, 1861.--Monthly Table of appar-

itions.-Dates of greatest frequency.-Results of calculations with reference

to these bodies.

CHAPTER III.

SHOOTING STARS.

Have only recently attracted attention.—Are visible with greater or less frequency

every clear night. Summaries of the monthly and horary rates of apparition

from observations by Coulvier-Gravier and Denning.-Number of known

meteor showers.-Their distribution amongst the constellations.-Monthly

number of meteors catalogued.-Early notices of great meteor showers.-The

showers of 1799, 1831, 1832, 1833, 1866, and following years.-The shower

of Aug. 10.-Of Nov. 27, 1872, and Nov. 27, 1885.-Nomenclature of meteor

systems.-Views of Olbers.-Monthly summary of great meteoric dis-

plays.
608-25

CHAPTER IV.

THE THEORY OF METEORS.

Meteors are planetary bodies.-Their periodicity.-Meteoric orbits.-Researches of

Newton and Adams.-Orbit of the meteors of November 13.-Identity of the

orbits of comets and meteors.-The meteor showers of Nov. 13 and 27.-Recent

progress of Meteoric Astronomy.—Table of the chief radiant points. 626-38

CHAPTER V.

RADIANT POINTS.

Explanation of Reference Letters in the List of Radiant Points.

CHAPTER VI.

TELESCOPIC METEORS.

639-43

Our knowledge of them limited.—Observations.-Probable heights in the

atmosphere.-Showers of telescopic meteors.-Summary of Prof. Safarik's

observations and deductions.-Fireball observed in a telescope on Oct. 19,

1863.

644-50

II.

12.

(Anon.)

Plate I. Frontispiece.

Title-page.

8

Plate II.

II

II

16

18

18

19

19

7. Paths of Sun Spots at different times of the year
8. Great Sun Spot visible on June 30, 1883. (Ricco.)
9. The same Sun Spot on July 2, 1883. (Ricco.)
10. Great Sun Spot visible on July 25, 1883. (Ricco.)
The same Sun Spot on July 27, 1883. (Ricco.).
The Great Sun Spot of October 1865, Oct. 11, 11 A. M.
13. The Great Sun Spot of October 1865, Oct. 11, 12.30 P.M.
14 The Great Sun Spot of October 1865, Oct. 12, 9.30 A. M.
15. The Great Sun Spot of October 1865, Oct. 12, 10-30 A. M.
16. The Great Sun Spot of October 1865, Oct. 12, 12.30 P. M.
17. The Great Sun Spot of October 1865, Oct. 12, 2.30 P.M. (Brodie.)
18. The Great Sun Spot of October 1865. Pectinated edge

(Brodie.)
(Brodie.)
(Brodie.)

(Brodie.)

19. Diagram illustrating the connection between Aurora, Terrestrial Magnetism, and Spots on the Sun

20. Change of form in Spots owing to the Sun's rotation
21. Spot on the Sun, May 5, 1854, showing cyclonic action. (Secchi.)
22. Large Spot on the Sun in 1866 showing successive
changes of form

23. Spot seen on the edge of the Sun in 1884 exhibiting itself as a depression.

24. Faculæ on the Sun, December 3, 1865. (Tacchini.)
25. Spot on the Sun, July 29, 1860, showing the "Willow-
leaf" Structure. (Nasmyth.)

26. Spot on the Sun, January 20, 1865. (Secchi.)

27. "Rice-like" particles seen on the Sun. (Stone.)

28. Ideal View of the "Granular" Structure of the Sun.

29. Solar granules, 1866, showing cyclonic arrangement. (Huggins.) 30. Solar granules, 1866, ordinary arrangement. (Huggins.)

39

40

35.

36.

Relative apparent size of the Sun, as viewed from the

different Planets named

Comparative Sizes of the Planets

Page

55

56

58

61

62

63

37. Comparative Sizes of the Sun and Planets

Plate V.

65

39.

38. Conjunction of Venus and Jupiter, July 21, 1859

Conjunction of Venus and Saturn, December 19, 1845

40. The Ptolemaic System

69

70

71

the Earth's Rotation

View of a portion of the Moon's Surface.

58. Imitation of the structure of the Moon's Surface.

(Bergeron's experiment.)

.

59. The Lunar Mountain Aristarchus, illuminated

60. The Lunar Mountain Aristarchus, waxing 61. The Lunar Mountain Aristarchus, waning 62. The Peak of Teneriffe

63. The Lunar Mountain Archimedes

65. The Lunar Mountain Copernicus. (Nasmyth.) 66. The Lunar Mountain Archimedes.

97

Plate VI.

113

(Nasmyth.).

123

125

126

127

127

128

Plate VII.

129

129

129

(Weinek.)

67. The Lunar Mountain Gassendi. (Weinek.)
68. The Lunar Gulf Sinus Iridum. (Weinek.)
69. The Lunar Mountains Kepler and Encke. (Weinek.).
70. The Lunar Mountain Frascatorius. (Weinek.)

73. The Gulf of Iris seen when the Moon is 10 days old