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
Compound refractive lens Compound refractive lens A Compound refractive lens (CRL) is a series of individual lenses arranged in a linear array in order to achieve focusing of X-rays in the energy range of 5-40 keV. They are an alternative to the KB mirror. For all materials the refractive index for X-rays is close to 1, hence a single conventional lens for X-rays has an extremely long focal length (for practical lens sizes). In addition, X-rays attenuate as they pass through a material so that conventional lenses for X-rays have long been considered impractical. The CRL gets its reasonably short focal length, on