Editing Dome (section)

=== Hemispherical dome ===
[[File:Kupolvalv.svg|thumb|Hemispherical dome]]

The ''hemispherical dome'' is a surface formed by the rotation around a vertical axis of a [[semicircle]]. Like other "rotational domes" formed by the rotation of a curve around a vertical axis, hemispherical domes have circular bases and horizontal sections and are a type of "circular dome" for that reason. They experience vertical compression along their meridians, but horizontally experience compression only in the portion above 51.8 degrees from the top. Below this point, hemispherical domes experience tension horizontally, and usually require buttressing to counteract it.{{sfn|Arun|2006|p=304}} According to E. Baldwin Smith, it was a shape likely known to the Assyrians, defined by Greek theoretical mathematicians, and standardized by Roman builders.{{sfn|Smith|1950|pp=8, 9}}