Korneliy Udalov was returning from a business trip, and at the airport someone quietly replaced his bag. On the way home from the airport, Cornelius noticed that the bag gradually began to get heavier, and then a brick fell out of it... [Fourth] letter to the editor. Written in 1973. Signed: Nikolai Lozhkin. I confirm the testimony of N. Lozhkin: Korneliy Udalov. Addition “From the Editor”, attached is a letter from the inventor, G. K. Zavarukhin