Keystone

Rarity: Uncommon

A topic a little better known than average, read and translated beyond its own country.

Rarity follows how well known the article is: its views on the French and English Wikipedia over a year, and the number of languages it exists in.

At a glance

Class

Notion

Domain

Science and technology

In collections

Nobody has pulled it yet.

What Wikipedia says

A keystone (or capstone) is the wedge-shaped stone at the apex of a masonry arch or typically round-shaped one at the apex of a vault. In both cases it is the final piece placed during construction and locks all the stones into position, allowing the arch or vault to bear weight.

Excerpt from the Wikipedia article “Keystone (architecture)”, under the CC BY-SA 4.0 license. Read the article on Wikipedia

Image: Otto Lueger, Public domain, via Wikimedia Commons.