Washington DC: "Ars Boni" on the DOJ Building
The 1926 Public Buildings Act, which permitted the Government to hire private architects for the design of Federal buildings, heralded the beginning of the country's largest public buildings construction program. Among the most significant early projects generated under the new legislation was the development of a 70-acre site (now known as the Federal Triangle) between the Capitol and the White House.
A board of distinguished architects developed guidelines for the site, with the goal of providing each Government agency or bureau with a building that would address its functional needs, while combining the individual buildings into a harmonious, monumental overall design expressive of the dignity and authority of the Federal Government. Limestone facades, red-tile hipped roof, and classically inspired colonnades are common features of the Federal Triangle buildings. In a rare occurrence, I'd say this instance of planning by committee worked out pretty well.
The photograph here is of the top of the Constitution Avenue side eastern colonnade of the Department Of Justice Building (also known as the Robert F. Kennedy Building.) You can see the detail in the tiled roof, including the small acroteria, the upright ornaments along the edge and the peak of the roof. The Latin in bold relief inside the pediment, ARS BONI, comes from the sentence, Jus est ars boni et aequi, which is a quotation from an important Roman jurist with way too many names: Publius Juventius Celsus Titus Aufidius Hoenius Severianus (AD 67-130,) or "Celsus" to his friends. Celsus' aphorism translates to "law is the art of the good and the equitable." The colonnade on the west end of the building is similarly topped by a pediment that reads, ARS AEQUI, but ornamented with a different sculpture.
Since I've only given you a small slice of the DOJ Building, a good photograph, by M. V. Jantzen, of the building as a whole is here.