A vault is simply an arch extended

A vault is simply an arch extended lengthwise, and a semicircular one like the Romans used is a barrel vault. The later Romans discovered that one vault could cross another at right angles and still stand up; this cross vault could cover a large square area successfully, supported only at the corners on columns.
Outside, the first three levels of arcades are faced with Doric, Ionic, and Corinthian columns.

Результаты (английский) 1:

A vault is simply an arch extended lengthwise, and a semicircular one like the Romans used is a barrel vault. The later Romans discovered that one could cross vault another at right angles and still stand up; This cross vault could cover a large square area successfully, supported only at the corners on the columns.Outside, the first three levels of arcades are faced with Doric, Ionic, and Corinthian columns.

Результаты (английский) 2:

A vault is simply an arch extended lengthwise, and a semicircular one like the Romans used is a barrel vault. The later Romans discovered that one vault could cross another at right angles and still stand up; cross vault could this cover a large square area successfully, supported only at the corners on columns.
Outside, the first three levels of arcades are faced with Doric, Ionic, and Corinthian columns.

Результаты (английский) 3:

a vault is simply an arch extended lengthwise, and a semicircular one like the Romans used is a barrel vault. the later Romans discovered that one vault could cross it at right angles and still stand up; this cross vault could cover a large square area successfully, supported only at the corners on columns. outside, the first three levels of arcades are faced with Doric, Ionic,and Corinthian columns.