ClipArt ETC
Junction between an arch and the column, pier, or wall on which it rests.

Impost, Continuous

Junction between an arch and the column, pier, or wall on which it rests.

Junction between an arch and the column, pier, or wall on which it rests.

Impost, Discontinuous

Junction between an arch and the column, pier, or wall on which it rests.

Junction between an arch and the column, pier, or wall on which it rests.

Impost, Shafted

Junction between an arch and the column, pier, or wall on which it rests.