and Uranus. The last telescope of his construction had four feet of aperture, and was thirty-seven feet long. The impure atmosphere of a manufacturing centre like Liverpool prevented the utilization of the whole power of an instrument of such dimensions. Mr. Lassell resolved to transport it to Malta, where he had already installed, ten years before, a telescope of twenty feet. From 1862 to 1865 the new telescope was constantly turned toward the sky, and employed in scrutinizing its depths. Mr. Lassell discovered more than 600 new nebulæ, whose feeble light, under the humid sky of the North, had escaped the investigations of William Herschel and Lord Rosse. Mr. Lassell is now occupied in the publication of the numerous materials gathered during his two sojourns at Malta.
What an example and what instruction may be found in the long career of William Herschel, who passed half a century in sounding the mysterious depths of the universe! The son of a poor musician—burdened with a numerous family—he embraced the paternal profession, and went, when twenty years old, to try his fortune in England. He barely earned a living by giving music-lessons and directing concerts or oratorios, when he was appointed organist at Halifax, then soon after filled the same office in Bath. He passed his leisure time in studying works on astronomy. As he was not rich enough to purchase a telescope, he went to work, and, after a thousand attempts, succeeded in making, in 1774, a five-foot reflector, with which he observed Saturn's ring. Encouraged by this first success, the organist of Bath entered upon the construction of mirrors of seven feet, then ten, and twenty feet of focus. He made more than 200 before attaining the desired perfection, and the total number of mirrors that he worked upon in succession exceeded 400. In 1781 he had the good fortune to discover the planet Uranus, which extended the boundary of the solar system. He was then forty-three years old. This discovery drew upon him the attention of Europe; George III. granted him a pension and a dwelling at Slough, near Windsor Castle. He then commenced that methodical review of the heavens, by means of which he discovered more than 2,000 nebulæ, and suggested so many new views of the universe. The greatest part of his labor was executed with instruments of moderate dimensions; he rarely used the great telescope of forty feet, the mirror of which was easily tarnished by the action of the moisture of the night; he used it, however, in the discovery of the sixth satellite of Saturn. William Herschel died in 1822; the year before his death, at the age of eighty-three, he communicated his last paper to the Astronomical Society of London, which, since its foundation, had chosen him for president. In all his researches he was assisted by his sister Caroline, who had lived with him ever since she was twenty-two years old, and who aided him in his observations as well as in his calculations. In this way he was able to astonish the scientific world by the rapidity with which his publications succeeded each other. Caroline
