The eye-pieces and object-glasses, each in a separate tube, worked in a case 15½ inches in length by 5 inches in breadth, and 2 in depth, forming, with the bevelled corners, a flat octagon, covered with a species of shagreen, and mounted in silver. An exceedingly simple and ingenious arrangement, consisting of a double screw working four small arms of brass, was placed at each end for the purpose of regulating the distances between each pair of glasses, and silver dial plates enabled the operator to set the instrument according to his ascertained requirements. The instrument belongs to the Royal Institution of Liverpool, and is supposed tc have been part of a collection of rarities, made by Wm. Roscoe, in Italy. As a telescope, it is of great power; the focus is adjusted by one portion of the case acting as a draw-tube within the other part.