Fountain Pens

A fountain pen is a pen that contains a reservoir of water-based liquid ink. The ink is fed to the nib through a "feed" via a combination of gravity and capillary action. Filling the fountain pen reservoir with ink involves replacing a disposable ink cartridge, filling the pen with an eyedropper, or using one of a variety of internal mechanisms which suck ink into the reservoir from a bottle through the nib. Older pens had an internal rubber sac which was squeezed and released to create the suction needed. Most modern pens can use either a disposable cartridge, or a removable reservoir with a screw or piston mechanism (commonly called a converter) to fill the pen.
-- Courtesy Wikipedia