One theory of the development of the set is that Mr. Cooke had used prestigious architectural concepts, familiar to an expanding class of educated and prosperous gentry. London architects, strongly influenced by the culture of Greece and the culture of ancient Rome, were designing prestigious buildings in the neoclassical style. The appearance of the new chessmen was based on this style and the pieces were symbols of "respectable" Victorian society: a distinguished bishop's mitre, a queen's coronet and king's crown, a knight carved as a stallion's head from the Elgin Marbles from the Parthenon, and a castle streamlined into clean classical lines, projecting an aura of strength and security. The form of the pawns was based on the Freemasons' Square and Compasses; however, another theory regards the pawns' form as derived from the balconies of Victorian architecture. There were also practical innovations: for the first time a crown emblem was stamped onto a rook and knight of each side, to identify their positioning on to the king's side of the board. The reason for this is that in descriptive chess notation, the rooks and knights were often designated by being the "queen's knight", the "king's rook", etc.