Slavoljub Eduard Penkala, Croatian engineer, invented the mechanical pencil (b. 1871)
Slavoljub Eduard Penkala (Croatian pronunciation: [slâʋɔʎuːb ɛ̂duard pɛŋkǎːla]; 20 April 1871 – 5 February 1922) was a Croatian engineer and inventor of Dutch-Polish descent.