At the turn of the 20th century, St. Petersburg had 15 secondary educational establishments – classical, modern and military schools. Among the teachers of physics and mathematics we see names which became famous far beyond the history of secondary education. In the 4th Gymnasium, physics was taught by Apollon Pavlovich Afanasiev, who later became a university professor; another university professor, Karl Karlovich Baumgardt, taught physics and cosmology at the 8th Gymnasium named for Karl Mai, together with F. N. Indrikson, the author of the school physics textbook, who presented in his lectures a famous university general physics course of Professor O. D. Khvolson. Why did Friedmann's parents choose the 2nd Gymnasium as the place for Friedmann, Jr. to study for nine years? There appear to be two reasons. The first is that the gymnasium was relatively close to the house where they were living at the time. Friedmann's father occupied Apt. 4 in 35 Moika Street. The house exists today, under the same number; furthermore, as the cast-iron plaque on it says, it is protected by the state as an architectural monument of the early 19th century. Its corner looks onto the Zimnyaya Kanavka (canal, or, literally, ditch) and is next to the Naval Archives building, started in 1883 and completed one year before Friedmann's birth – in 1887; an inscription to that effect appears on the impressive facade looking onto Khalturin Street, formerly Millionnaya Street.