Pyotr Dmitriyevich En’ko
1844 - 1916 (1916?)
Doctor of medicine, director of the St. Petersburg School of the Deaf-mute since 1901. In 1910, he gave a conclusion regarding the suitability for educational purposes of photographic images in natural colors of various Russian regions from S.M. Prokudin-Gorsky following the results of their demonstration in the Pedagogical Museum of military schools.