in Architecture, a little round mould- ing, which in the orders surrounds the top of the shaft or body of the column. It is also called the talon and tondino; it is used at the bottom as well as tops of col- umns, and on other occasions: it properly represents a ring, on whatever part of a column it is placed; and the original idea of it was that of a circle of iron put round the trunk of a tree, used to support an edifice, to prevent its splitting. The astragal is often cut into beads and berries, and is used in the ornamented en- tablatures to separate the several faces of the archi- trave.

in Gunnery, a round moulding encom- passing a cannon, about half a foot from its mouth.