TABLE OF CONTENTS.
| The Orion Nebula, | [Frontispiece] | ||
| The Crossley Reflector of the Lick Observatory, | Page | [11] | |
| List of Nebulæ and Clusters Photographed, | " | [30] | |
| Catalogue of New Nebulæ Discovered on the Negatives, | " | [31] | |
| Positions of Known Nebulæ Determined from the Crossley Negatives, | " | [42] | |
| List of Illustrations, | " | [45] | |
| Illustrations, | following | " | [46] |
THE CROSSLEY REFLECTOR OF THE LICK OBSERVATORY.[1]
By James E. Keeler.
The Crossley reflector, at present the largest instrument of its class in America, was made in 1879 by Dr. A. A. Common, of London, in order to carry out, and test by practical observation, certain ideas of his respecting the design of large reflecting telescopes. For the construction of the instrument embodying these ideas, and for some fine astronomical photographs obtained with it, Dr. Common was awarded the gold medal of the Royal Astronomical Society in 1884.