Analysis of information sources in references of the Wikipedia article "First Dynasty of Egypt" in English language version.
Large tombs of pharaohs at Abydos and Naqada, in addition to cemeteries at Saqqara and Helwan near Memphis, reveal structures built largely of wood and mud bricks, with some small use of stone for walls and floors. Stone was used in quantity for the manufacture of ornaments, vessels, and occasionally for statues. Tamarix was used to build boats such as the Abydos Boats. One of the most important indigenous woodworking techniques was the fixed mortise and tenon joint, where the fixed tenon was made by shaping the end of one timber to fit into a mortise (or hole) that is cut into a second timber. A variation of this joint using a free tenon eventually became one of the most important features in Mediterranean and Egyptian shipbuilding. It creates a union between two planks or other components by inserting a separate tenon into a cavity (mortise) of the corresponding size cut into each component.
