Chronology, 1774-1893—Chemical Elements in the Sun (Rowland, 1891)—Epochs of Sun-spot Maximum and Minimum from 1610 to 1901—Movements of Sun and Stars—List of Great Telescopes—List of Observatories employed in the Construction of the Photographic Chart and Catalogue of the Heavens
[Photograph of the Great Nebula in Orion, 1883] Frontispiece
[Photographs of Jupiter, 1879, and of Saturn, 1885] Vignette
[Plate I. Photographs of the Solar Chromosphere and Prominences] To face p. 198
[Plate II. Photograph of the Great Comet of May, 1901 (Taken at the Royal Observatory, Cape of Good Hope)]
[Plate III. The Great Comet of September, (Photographed at the Cape of Good Hope)]
[Plate IV. Photographs of Swift's Comet, 1892]
[Plate V. Photographic and Visual Spectrum of Nova Aurigæ]
[Plate VI. Photograph of the Milky Way in Sagittarius]
HISTORY OF ASTRONOMY
DURING THE NINETEENTH CENTURY
We can distinguish three kinds of astronomy, each with a different origin and history, but all mutually dependent, and composing, in their fundamental unity, one science. First in order of time came the art of observing the returns, and measuring the places, of the heavenly bodies. This was the sole astronomy of the Chinese and Chaldeans; but to it the vigorous Greek mind added a highly complex geometrical plan of their movements, for which Copernicus substituted a more harmonious system, without as yet any idea of a compelling cause. The planets revolved in circles because it was their nature to do so, just as laudanum sets to sleep because it possesses a virtus dormitiva. This first and oldest branch is known as "observational," or "practical astronomy." Its business is to note facts as accurately as possible; and it is essentially unconcerned with schemes for connecting those facts in a manner satisfactory to the reason.