Daniel Schwenter (Schwender) (31 January 1585, Nuremberg – 19 January 1636, Altdorf bei Nürnberg) was a German Orientalist, mathematician, inventor, poet, and librarian. He was professor of oriental languages and mathematics at the University of Altdorf. His works include Delicia Physico-Mathematicae (Nuremberg, 1636) and Geometriae practicae novae et auctae tractatus I-IV (published posthumously in 1641). As a linguist, Schwenter was familiar with Greek, Hebrew, Arabic, Syriac, and Aramaic. He was also an authority on Euclid.
He is credited with developing the scioptric ball in 1636. This is a universal joint that allows a microscope, mounted on the ball, to be swiveled into any position. Its invention was inspired by Schwenter's studies of the human eye. The scioptric ball provided a firm anchor for a microscope or telescope while allowing the telescope to be swiveled in all directions in order to follow the course of an eclipse or for drawing panoramic views. It was in some ways the first wide-angle lens.
Schwenter did not invent the fountain pen, but in 1636, in his Delicia Physic-Mathematicae, he described a pen made from two quills. One quill served as a reservoir for ink inside the other quill. The ink was sealed inside the quill with cork. Ink was squeezed through a small hole to the writing point.