Though the earliest records that talk about a reservoir pen dates back to the 10th century, the modern fountain pen with a replaceable ink cartridge as we know it was invented by Petrache Poenaru, a Romanian inventor. He received a patent issued by France in 1827.
Petrache Poenaru completed his advanced studies in England and besides inventing the fountain pen he also founded the Philharmonic Society, The National Museum of antiquities, and Botanical Gardens in Bucharest. Following his invention, there were a number of other fountain pen patents that were filed and finally with the inventions of free flowing ink, iridium tipped gold nib and hard rubber, the fountain pen became a popular writing instrument.
A fountain pen uses a nib for writing and can store liquid ink which is water-based in a reservoir in contrast to the older versions. A feed is used for drawing ink from the reservoir to the nib. Both capillary and gravity actions are combined for drawing ink to the paper. Therefore the fountain pen requires practically no pressure to write. The ink could be filled in the reservoir by using syringe or eyedropper manually, or by an inner “filler” mechanism that sucks in the ink into the reservoir through the nib. Some pens have pre-filled ink cartridges that can be removed and replaced.