Joist were typically planed smooth (wrought) and sometimes chamfered or beaded. Joists may join to their supporting beams in many ways: joists resting on top of the supporting beams are said to be "lodged"; dropped in using a butt cog joint (a type of lap joint), half-dovetail butt cog, or a half-dovetail lap joint. Joists may also be tenoned in during the raising with a soffit tenon or a tusk tenon (possibly with a housing). Joists can also be joined by being slipped into mortises after the beams are in place such as a chase mortise (pulley mortise), L-mortise, or "short
Mitre Corporation Mitre occupied in September 1959. After the SAGE project ended in the early 1960s, the FAA selected Mitre to develop a similar system to provide automated air traffic control. The result of the project formed the National Airspace System (NAS), that is still in use today. To support the NAS project and continual operations with the U.S. Department of Defense at the Pentagon, Mitre opened a second "main office" in McLean, Virginia. Through the 1960s, Mitre developed and supported military Command, Control, Communications and Intelligence (CI) projects, including the Airborne Warning and Control System (AWACS). Mitre also worked on a