Magnification, the seminal feature of telescopes, was known as far back as A.D. 1000. A glass sphere called a reading stone was laid on top of the material to be read, magnifying the letters. Salvino D'Armate, an Italian, is credited with inventing the first wearable eyeglasses around 1284, and by the early 1400s eye glassmakers flourished throughout Europe. At that time, the basic similarity between reading lenses and telescopes had not yet been understood. The first generation of astronomers to peer great distances through small, primitive telescopes, and understand that their hands held the key to understanding the cosmos, would not arrive for another two hundred years. Until then, the small, blurry, distant specks in the night sky would remain nothing more than that, even though thinkers for thousands of years had suspected there was more to them than met the eye.

Lenses and Cylinders