Slavoljub Eduard Penkala was born to a Polish father and Dutch mother in modern-day Slovakia in 1871 and went on to patent a number of inventions. After graduating from the University of Vienna and Technische Universität Dresden with a doctorate in organic chemistry, Penkala moved with his wife and family to Zagreb where he marked his loyalty to his new homeland by becoming a naturalized Croat.
Penkala became renowned for further development of the mechanical pencil (then called an “automatic pencil”) and the first solid-ink fountain pen. 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. This company, now called TOZ Penkala, still exists today in Zagreb.
He also constructed the first Croatian aircraft to fly in the country, the 1910 Penkala Monoplane,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 hot water bottle—his first patented invention, the “Termofor”
a type of bluing detergent
a rail-car brake
an anode battery
He also founded another company called the Elevator Chemical Manufacturing Company, which produced various chemicals such as detergents, sealing wax, and “Radium Vinovica”, a patent-medicine–like product that was billed as curing rheumatism. Penkala died in Zagreb at the age of 50, after catching pneumonia on a business trip. He was buried at the Mirogoj Cemetery.