An article on wood technology, with particular reference to a cambered truss invented in the 19th century. The author demonstrates that the linear wood elements from tree trunks require connections, joints and rabbets for two or three dimensional structures. Thus simple pieces of the same material are jointed, ensuring the solidity of the finished article. Three kinds of joints with contact profiles, made of non-resinous wood (oak, chestnut, walnut) are analyzed. The beams work if stressed by bending or traction. The beams take the bending and tractional forces present just as if they were a single element.