Karol Hertz was a Polish mathematician, pedagogue and journalist in natural science. In years 1862-1866 studied at theWarsaw Main School at the Faculty of Mathematics and Physics, finishing with his master in 1866. In 1871 he received Ph. D. from the University of Halle and from 1867 he was working at the Second Gimnazjum inWarsaw. He has written three monographs, three text-books, some articles in mathematics and several articles of scientific character published in the journals Nature and Industry and the Week Review ofSocial, Literary and Fine Arts Life, and in its monthly Supplement. He also translated into Polish language many books and articles in mathematics, physics, astronomy, philosophy and pedagogy.