Decorative elements are an important part of the artistic image of an architectural structure. Each architectural style has its own particular set of decorative details. One of them is the capstone. Architects usually showed its significance through its large size.
What is a keystone in architecture?
So in the structure it is customary to call an element strongly protruding from the plane of the wall, crowning an arch or arched vault. It is usually wedge-shaped. Made from expensive materials. In addition, the decorative keystone also has a functional meaning - it strengthens the arched structure in its most unstable, fragile place.
Stone as a symbol
The expression "keystone" eventually entered our everyday life and became a symbol of strength and stability, based on the most important, central element of the entire "construction". For example, in politics - a society that is firmly held by the strong and wise power of the rulers. In Christianity, the "keystone" is often called the Bible as the basis of religious doctrine andthe fact of the resurrection of Jesus Christ as the foundation of religion. In the event of a refutation or rejection of this fact, the Christian religion itself would be doomed.
History
Arched structures were first used in the building art of the Etruscans. They were adopted later by the ancient Romans and revered as a miracle. That is why they accompanied the ceremony of laying the capstone into the arched structure with ritual actions. The Romans made this detail from expensive types of stone and wood. At that time, the keystone was not superimposed on the design of the arch. He drove into it like a wedge in such a way that he became her spacer and took on most of the load of the vault on the supports.
Capstone: type, purpose
As for the decorative decoration of the structure, the capstones are simple, consisting of three wedge-shaped parts, the central of which protrudes more than the side ones. Often decorated with a relief or mascaron - a relief image of the muzzle of an animal or a person's face.
Animal motifs in the design of the keystones had a symbolic meaning, similar in meaning to the ancient amulets depicted on "towels" - boards connecting the junction of the porches of the roof of the end facade of the hut. In both cases, they performed a protective function. Also, a sign containing information about the author of the building could be placed on the capstone. Something like a hallmark or monogram. This tradition has been preserved since the Middle Ages. The most common image of a lion's muzzle. After all, the lions werea traditional symbol of fortitude, strength, courage and courage, as well as power in medieval cities. They guarded the entrance to the houses of nobles and were depicted even on the entrance handles.
Use in St. Petersburg styles
The new European city of St. Petersburg, which arose on the banks of the Neva, at the first stage had a hut and wooden buildings. However, after 1718, on Vasilevsky Island, and a little later on the left bank, they began to build typical stone houses according to the project of the first architect of the city, Domenico Trezzini. The style of Petersburg in the first quarter of the 18th century is usually called Peter's or early Russian baroque. One of the characteristic decorative elements was simple window frames with "ears" at the corners. Others - a keystone in the center of the upper crossbar of the casing or above it. This decorative stone at that time was very laconic and, as a rule, was not decorated with any frills.
In the era of Elizabeth Petrovna, keystones began to have a more decorative appearance. They were decorated with vertical grooves, coats of arms and relief decorations, ornaments, and sometimes they were completely replaced with stucco molding. During this period, the facades of buildings were cut through with windows of various shapes, including in the form of a semicircular arch, where the keystone found its "refuge". By the way, for the first time it began to be used precisely on arches of this type - back in ancient times, usually in classical architecture.
Since the 1830s in St. Petersburg, classicism, in the decor of which the keystones were made inmainly in the form of mascarons, gradually gave way to the next style - eclecticism.
Within the framework of this style, there was a direction "historicism", reviving in new combinations and meanings the decorative elements of previous architectural styles. Various types of decorative capstones can also be found on buildings from this period.
And at the beginning of the 20th century, in the architecture of the northern Art Nouveau, keystones began to be made using plant and zoomorphic motifs.
