1) Unit of area 
A quinaria (plural: quinariae) is a Roman unit of area, roughly equal to 4.2 square centimeters (0.65 sq in). Its primary use was to measure the cross-sectional area of pipes in Roman water distribution systems. A `one quinaria` pipe is 2.31 centimeters (0.91 in) in diameter. In Roman times, there was considerable ambiguity regarding the origin .....