Sir David Brewster thus eloquently sketches the powers of the telescope at the close of his able description of the instrument, which we have in part quoted from his _Life of Sir Isaac Newton_. We have, in the mornings, walked again and again, and ever with new delight, along its mystic tube, and at midnight, with its distinguished architect, pondered over the marvellous sights which it dis-closes,--the satellites and belts and rings of Saturn,--the old and new ring, which is advancing with its crest of waters to the body of the planet,--the rocks, and mountains, and valleys, and extinct volcanoes of the moon,--the crescent of Venus, with its mountainous outline,--the systems of double and triple stars,--the nebulæ and starry clusters of every variety of shape,--and those spiral nebular formations which baffle human comprehension, and constitute the greatest achievement in modern discovery. The Astronomer Royal, Mr. Airy, alludes to the impression made by the enormous light of the telescope,--partly by the modifications produced in the appearance of nebulæ already figured, partly by the great number of stars seen at a distance from the Milky Way, and partly from the prodigious brilliancy of Saturn. The account given by another astronomer of the appearance of Jupiter was that it resembled a coach-lamp in the telescope; and this well expresses the blaze of light which is seen in the instrument. The Rev. Dr. Scoresby thus records the results of his visits: