How does a fountain-pen work?

A pen, that carries a supply of ink inside it, is called a fountain-pen. This ink supply is in a reservoir, either a disposable cartridge or a rubber, sac-like container inside the pen’s barrel. Disposable cartridges can be removed completely and replaced with a new one when they run dry, but the sac is filled by a different method. On the side of the pen’s barrel, is a lever. When you pull out on the lever, its other and pushes inside the pen and presses against the sac. This forces out the air from the empty sac. Then when you place the tip or nib of the pen into a bottle of ink and release the lever, the ink is down up through tiny tubes into the sac. This is called the vacuum method, since the vacuum inside the sac draws up the ink. The first working fountain-pen, developed in 1884 by Lewis Water man, had to be filled with ink from an eye-dropper!