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 Nearly three hundred years ago John Battista Porta, a Neapolitan, made a hole in a wall in front of a dark room, and noticed that the rays entering, cast a shadow picture of the things outside. The hole was a projected eyeball, and the wall a choroid or curtain behind it. Gazing in wonder through this new order of eyeball, Battista Porta began to think of furnishing it, of putting something more behind it, and he put in—the first thing that he would have met if he had been examining his own eye—a lens! In that hour the long ages of free exercise closed. One eye-instrument maker after another appeared, and the eye unshrouded itself. One of the greatest was Galileo, a doctor, who was not only a great projector of the eye, but was the first projector of the pulse in the clock or timepiece. "He took an old small organ pipe, jammed a spectacle-glass into either end, and behold! a magnifying glass!" Crowds