One of the preliminary design variants for Konstantin Chaykin’s third "Easter Computus" clock, in which he explores an architectural prototype for the piece.

In this case the reference is the "Church of the Dormition of the Mother of God" on Vasilyevsky Island in Saint Petersburg, built by architect Vasily Kosyakov in the Russian Revival style. For the final version of the design, Konstantin Chaykin chose "Saint Isaac’s Cathedral" as the prototype.