Arch, Catenarian

Arch, Catenarian. If a chain or rope is suspended at equal elevations at its two ends and allowed to hang slack affected only by gravity, it will always form a graceful curve, called a catenary curve (Latin catena, chain). If this is inverted, it is called a catenary or catenarian arch. The ritual of the Royal Arch Degree used in England asserts that the arch involved there is a catenarian arch. No such term appears in the American work.