Benjamin Franklin invented, among other things, bifocal glasses, a much-improved wood stove and an effective mail service.
He invented bifocals and the lightning rod.
one of ben franklins is the bifocals because he didn't want to keep having two glasses around his neck and keep switching them
Two useful and well known inventions of Benjamin Franklin include the Franklin stove and the lightening rod. Also, Ben Franklin invented the glass harmonica and bifocals.
The bifocals were invented in 1784, by Benjamin Franklin, because he had seeing problems, and put two lenses of glass together to magnify his vision.
Henry Dudeney has invented two things. Henry Dudeney invented logic puzzles and mathematical games.
what are two things summerians invented
The very first eyeglasses were invented in 1286, but many later developments were made that improved on the initial designs. Benjamin Franklin invented bifocals, glasses with two distinct optical powers, and George Airy invented lenses correcting astigmatism.
Warships and Airplanes.
The Franklin Long arm, which has a long pole, and a sort of U-shaped two cupped grasping devices at the top, and usually two lever grips to actuate the Spring-loaded arm. Franklin invented this device in Colonial times- still in everyday use in many stores. It is a funny thing for drawing practice, hard to draw shape.
Benjamin Franklin had a number of inventions, but never patented a single invention. Some of the more memorable Franklin inventions are the bifocal glasses, the Franklin stove, lightening rod, long arm reaching device, glass harmonica, political cartooning, odometer, swim fins, and urinary catheter.
Ben Franklin had poor vision and got tired of putting on his spectacles, and having to take them off again, so, he invented a way to see both near and far by taking half of a lens from two different pairs of spectacles and put each half into a single frame. He called them bifocals. The year he invented them was 1784.
he invented the church of england(and divorce)