Res Gestae

Now an obelisk is a very hard stone, rising gradually somewhat in the form of a turning-post[*](A meta was one of the three conical columns on the end of the spina of a circus.) to a lofty height; little by little it grows slenderer, to imitate a sunbeam; it is four-sided, tapers to a narrow point, and is polished by the workman’s hand.