The glass armonica, Franklin stove, lightning rod, and bifocal glasses — did you know that Benjamin Franklin devised or improved upon these inventions?... | By WKNO | Facebook
The glass armonica, Franklin stove, lightning rod, and bifocal glasses — did you know that Benjamin Franklin devised or improved upon these inventions?... | By WKNO | Facebook
The glass armonica, Franklin stove, lightning rod, and bifocal glasses — did you know that Benjamin Franklin devised or improved upon these inventions?... | By WKNO | Facebook
The glass armonica, Franklin stove, lightning rod, and bifocal glasses — did you know that Benjamin Franklin devised or improved upon these inventions?... | By WKNO | Facebook
![ben franklin and bifocals 1760s AD. Benjamin Franklin invents the bifocal. | Bifocal, Bifocal lenses, Eyeglass lenses ben franklin and bifocals 1760s AD. Benjamin Franklin invents the bifocal. | Bifocal, Bifocal lenses, Eyeglass lenses](https://i.pinimg.com/originals/ba/8e/84/ba8e84853e162d3f48495ebba3c9df7c.jpg)