true domes, but are constructed using the corbel arch. Ashlar masonry was also heavily used in the construction of palace facades on Crete, including Knossos and Phaistos. These constructions date to the MM III-LM Ib period, c. 1700–1450 BC. In modern European masonry the blocks are generally about in height. When shorter than , they are usually called small ashlar. As metaphor In some Masonic groupings, which such societies term jurisdictions, ashlars are used as a symbolic metaphor for how one's personal development relates to the tenets of their lodge. As described in the explanation of the First Degree Tracing Board, in Emulation and other Masonic rituals the rough ashlar is a stone as taken directly from the quarry, and allegorically represents the Freemason prior to his initiation; a smooth ashlar (or "perfect ashlar") is a stone that has been smoothed and dressed by the experienced stonemason, and allegorically represents the Freemason who, through education and diligence, has learned the lessons of Freemasonry and who lives an upstanding life. See also Ablaq Dimension stone Opus quadratum Stone cladding Stone veneer References External links Building stone Stonemasonry Types of wall Wallcoverings Architectural elements Garden features Masonic symbolism