Constantin Miculescu

Constantin Miculescu (September 6, 1863, Crevenicu - December 29, 1937, Bucharest) was a Romanian physician and had notable results in thermodynamics and optics. His main contribution to physics can be found even in his doctoral dissertation, in which he presented a precise method for the determination of the mechanical equivalent of heat (calories).

Between 1882-1886 he attended the Faculty of Sciences, Department of Physics and Mathematics, University of Bucharest, where he had Emanoil Bacaloglu as a teacher. He obtained a scholarship in 1888 at Paris University, obtaining a degree in science from the Sorbonne. He completed his doctor's degree with thesis Sur la determination de l'équivalent mécanique de la calorie, under the guidance of Professor Gabriel Lippmann (1845-1921), future laureate of Nobel Prize for Physics in 1908.

In 1891 he occupied as a substitute teacher the chair remained vacant after the death of Emanoil Bacaloglu, then (1894) he became Professor of molecular, acoustic and optical physics, post he occupied until his death in 1937. Since 1900, he served as inspector of education and member of the Permanent Council of the Ministry of Education. He was elected in 1904 as a member of the Governing Board of the French Physical Society and in 1909 as a member of the International Committee responsible for collecting and publishing constants in chemistry, physics and technology of the Congress of Chemistry in London. Between 1923-1928, Prof. Dr. Constantin Miculescu was Dean of the Faculty of Sciences in Bucharest.

Constantin Miculescu invented a calorimeter and an original method for accurately measuring the mechanical equivalent of heat. Hence, the 4.1857 J/calorie value was taken over as such by the international tables, becoming a fundamental constant of thermodynamics. In 1950, the value established by Miculescu has only its 4th decimal corrected, i.e. 4.1855 J/calorie. He also organized the molecular, acoustical and optical physics laboratories of the Bucharest University, where he invented in i905 a method for determining the refractive index of a prism with a microscope, then in 1910 an acoustical method for measuring the elasticity coefficient of objects.