Ionic order cap is usually enriched with egg-and-dart. Since Vitruvius, a female character has been ascribed to the Ionic (in contrast to the masculine Doric). The major features of the Ionic order are the volutes of its capital, which have been the subject of much theoretical and practical discourse, based on a brief and obscure passage in Vitruvius. The only tools required to design these features were a straight-edge, a right angle, string (to establish half-lengths) and a compass. Below the volutes, the Ionic column may have a wide collar or banding separating the capital from the fluted shaft (as in, for
Simon Bosboom after the dismissal of Willem de Keyser, and in 1657, the year of Van Campen's death, Bosboom was promoted to city architect. Just as Hubertus Quellinus had done for the city hall in 1665, Bosboom published a small instructional booklet on architecture with engravings after Vincenzo Scamozzi entitled "Cort onderwys van de Vyf Colommen"; or "Short instruction on the five columns (Doric, Ionic, Corinthian, Tuscan, Composite)". His book earned him an honorary place in Cornelis de Bie's book of artists. He wrote that he helped Jacob van Campen and Artus Quellinus with decorations for the City Hall of Amsterdam, built