successive blow seemed to intensify his apprehension, and the rebound of his feelings was something startling, when a voice from beneath sung out, "All's right." The tapping was the attempt of his son to detach the greatest lens in the world from the pitchbed, in which it was stuck fast for the purpose of grinding. A blow, in the slightest degree too strong, would be the destruction of the labour of many months, and the loss of some thousands of dollars. Now that the lens was safely detached, and the burden removed from his mind, Mr Clarke was free to pour out his genial nature, and exhibit the refreshing enthusiasm of a man whose heart is thoroughly in his work. He pointed with pride to a lens lying before him, the fellow of the one that had caused him so much anxiety. This was the great object of our curiosity, and well might a lover of lenses make a long pilgrimage to see such a sight. It is eighteen inches in diameter, a size far exceeding that of any existing telescope of value. The telescope in the Russian Observatory of Pulkowa, by Frauenhofer, and long considered the best in the world, is only fifteen inches. The great equatorial of Cambridge Observatory, connected with Harvard University, was executed by the successors of Frauenhofer in Munich, Merz and Mahler, and is believed to be somewhat superior, besides being one-eighth of an inch greater in diameter. This one-eighth enabled our Transatlantic friends to boast of having the
