Spectacles and Eyeglasses: Their Forms Mounting and Proper Adjustment. E-book. Formato PDF - 9780259690788

Spectacles and Eyeglasses: Their Forms Mounting and Proper Adjustment. E-book. Formato PDF. The testimony as to their use by the Romans during their supremacy is of a less conclusive character. The statement frequently made that the Emperor Nero used a concave jewel to assist his sight rests upon some obscure sentences in Pliny. That author says Nero could see nothing distinctly without winking and having it brought close to his eyes. (bk. II, Chap. 54, Riley's Trans.) In another place, speaking of the emerald, smaragdus, he says In form these are mostly concave, so as to te unite the rays of light and the powers of vision. When the surface of the smaragdus is ?at, it re?ects the image of objects in the same manner as a mirror. The Emperor Nero used to view the combats of gladiators upon (with, or by means of) a smaragdus. (bk. 37, Chap.