6.
The ballpoint pen, a fountain pen in which the point s a tiny ball bearing, was developed in fairly recent times. The ball pen used today was invented in 1944 by Lazlo Biro, an Argentinian. Biro's pen had an accurately ground steel ball, only one twenty-fifth of an inch in diameter. It was the first ball pen that could make the fine lines of a fountain pen. Biro patented his invention in the United States and sold the rights to an American manufacturer.