Phenomenon of classical architecture comes from an impressive multivariance of it would seem a small set of architectural motives and specific order canons. Heritage of two leading maestros of Catherine era - Italian Giacomo Quarenghi and Scotch Chales Cameron, serves as a spectacular example of this fact.

Architectural forms by G. Quarenghi - are an example of the most strict classicism. It is not by chance that he created big public buildings of Saint Petersburg: Academy of sciences, State Assignat bank, Smolny Institute.
The facade of Academy of sciences is a vivid incarnetion of classical formula: "noble simplicity and calm splendour". Here laconism and semblant simplicity of the order architecture are brought up to the absolute.