PETZVAL, Jozef Maximilián

P.’s interest in mathematics has already been shown in High school in Podolíncu and Levoča and at an early stage of a three-year philosophical school at the Royal Academy in Košice he has shown some knowledge of advanced mathematics. From 1826, P. studied at the "Institutum Geometricum" in Budim and after two years of study and practice obtained an engineering degree. Initially he remained in Pest, where he designed a plan for navigation channels in the city and executed the necessary measurements. In addition to his practical work he completed his studies with a doctorate in mathematics in 1832. The same year he was appointed associate professor of mathematics, mechanics and practical geometry by the university. In 1835 he was appointed professor of higher mathematics. In 1837, P. followed the invitation to the Vienna University. Up to 1877 he held lectures on the theory of linear and differential equations, algebraic equations, intense cable vibrations, a circular movement as well as ballistics and analytical mechanics. In addition to mathematics, P. also worked closely on physics, especially photographic optics. At the request of Andreas von Ettingshausen, who got acquainted with photographic work of Mandéa Louis Jacques Daguerre in Paris, he began with the calculations for the lenses used for portraits and landscapes in 1839. Ettingshausen, inter alia, introduced him to Vienna optician Friedrich → Voigtländer, who made the first prototypes of the new lenses, based on P.’s calculations. P.’s original contribution to this was a double achromatic lens, which served as the basis for further development of photographic optics. P.’s calculations were also the basis for the development of telescopes, microscopes, theodolites and projection equipment. After sharp dispute with → Voigtländer over the primacy, with whom he separated in 1845, he also cooperated with optics producer Carl Dietzler in continuation of his career.
After the successful calculations Dietzler made a camera with double thread and a variable focal length, which was presented by P. at the convention of the German doctors and scientists in Vienna. P.-Dietzlers lens patented in the following year had three times the luminous intensity as → Voigtländers and it was exported to France and England. In addition to its calculations on the lenses, P. also worked with electric headlights. He designed a portable reflector with a diameter of 1.3 m, which was able to illuminate objects up to 2.7 km away. Since 1860 P. devoted his attention to acoustics. The principle of maintaining the continuance of oscillation led to a polemic with Christian →Doppler, which was resolved by P.’s student Ernst →Mach, in such a way that he demonstrated that the principles were not in opposition.