Eduard Slavoljub Penkala — a Croatian engineer and inventor of Dutch-Polish descent — was born on 20 April 1871
He became renowned for further development of the mechanical pencil (1906) - then called an "automatic pencil" - and the first solid-ink fountain pen (1907).[4] On 24 January 1906 he registered the patent for an automatic pencil. Collaborating with an entrepreneur by the name of Edmund Moster, he started the Penkala-Moster Company and built a pen-and-pencil factory that was one of the biggest in the world at the time. As the business grew, a second factory was set up in Berlin. The company, now called TOZ Penkala, still exists today.
He also constructed the first Croatian aircraft to fly in the country, the Penkala 1910 Biplane, flown by Dragutin Novak, who was also the first Croatian pilot. He constructed and invented many other products and devices, and held a total of 80 patents.
Among his patented inventions were:
a thermophore
a hot water bottle - his first patented invention, the "Termofor"
a type of bluing detergent
a rail-car brake
an anode battery