Jacob Metius else from claiming them. In October 1608, the States General discussed Jacob Metius's patent application for a device for "seeing faraway things as though nearby," consisting of a convex and concave lens in a tube, and the combination magnified three or four times. His use of a convex objective lens and concave eyepiece may have been a superior design to Hans Lippershey telescope design which was submitted for patent only a few weeks before Metius'. Metius informed the States General that he was familiar with the secrets of glassmaking, and that he could make an even better telescope with the
Lens clock clock can be used if a dial thickness gauge is not available. To do this, the contact lens is placed concave side up on a table or other hard surface. The lens clock is then brought down on it such that the center prong contacts the lens as close to its center as possible, and the outer prongs rest on the table. The thickness of the lens is then the sagitta formula_4 in the formula above, and can be calculated from the optical power reading, if the distance between the outer prongs is known. Lens clock A lens clock is