Mr. Alvin Clark, of Cambridgeport, Mass., who was a portrait painter, has now turned his attention to the manufacture of telescopes, and with one of his own instruments he has discovered many double stars not hitherto known, and his observations have been communicated to the Royal Astronomical Society of London, who have confirmed some of his observations. It is to be hoped that an opportunity will be afforded him to construct a large telescope, his largest now being only 7 inches in diameter. One which he made for the use of the Coast Survey, at a cost of $2400, is said to have been so good that a pole three inches in diameter could be seen at a distance of fifty miles when the atmosphere was clear, but we think that this distance is almost too far to be true.