Lesson 2: Cathedrals and Eiffel Tower vs St. Louis Arch

Why gravity loads of a nave create horizontal thrust on the aisle of a church structure? - the nave is so large and is concave down the length of the nave, putting the weight on the sides of the aisles. What century do we start the beginning of "engineering" of cathedrals? - 11-12 century Two reasons why we have more knowledge of the design of medieval cathedrals, than we do about ancient roman structures. - Documents destroyed Secretive group of masons What is a masonry vault? - Arched ceiling of stone or concrete structure Why a masonry vault must be in compression, not bending? - If in tension and cracks, three points is a machine and everyone dies Argue for or against the importance of the unique properties of masonry in the construction of medieval cathedrals. - There was nothing special to process the bricks or grout, but the form is special. Explain why iron is used at the tops of columns in medieval cathedrals. - For sheer weight to keep the vertical load pointed down Two benefits of pointed arch. - Taller for a given widt