<P> During finals in the winter, fires in the enormous fireplace are lit, to promote a comforting and pleasant atmosphere for the dozens of students typically found studying into the late hours . </P> <P> The Cathedral is home to 30 Nationality Rooms located on the first and third floors: 28 working classrooms and two rooms used mostly for display or occasional special events . Each nationality room is designed to celebrate a different culture that had an influence on Pittsburgh's growth, depicting an era prior to (or in the singular case of the French Classroom, just after) 1787, which is year of the university's founding and the signing of the US Constitution . </P> <P> The Nationality Room programs began in 1926 when Bowman decided that he wanted to involve the community as much as he could in constructing the Cathedral, so he proposed that each nationality that had a significant number of people in Pittsburgh would be allowed to design their nationality's room for the Cathedral . Each group had to form a Room Committee, which would be responsible for all fundraising, designing, and acquisition . The university provided only the room and, upon completion, upkeep for perpetuity . All other materials, labor, and design were provided by the individual committees . These were sometimes aided by foreign governments and the rooms contain many authentic artifacts and materials from the country represented . A typical room on the 1st floor (those built between 1938 and the 1957) took between three and ten years to complete, and cost the equivalent of US $300,000 in 2006 dollars . More recent rooms have cost in the range of $750,000 and up . </P> <Table> <Tr> <Td> <Ul> <Li> African Heritage </Li> <Li> Armenian </Li> <Li> Austrian </Li> <Li> Chinese </Li> <Li> Czechoslovak </Li> <Li> Early American (Display) </Li> </Ul> </Td> <Td> </Td> <Td> <Ul> <Li> English </Li> <Li> French </Li> <Li> German </Li> <Li> Greek </Li> <Li> Hungarian </Li> <Li> Indian </Li> </Ul> </Td> <Td> </Td> <Td> <Ul> <Li> Irish </Li> <Li> Israel Heritage </Li> <Li> Italian </Li> <Li> Japanese </Li> <Li> Lithuanian </Li> <Li> Korean </Li> </Ul> </Td> <Td> </Td> <Td> <Ul> <Li> Norwegian </Li> <Li> Polish </Li> <Li> Romanian </Li> <Li> Russian </Li> <Li> Scottish </Li> <Li> Swedish </Li> </Ul> </Td> <Td> </Td> <Td> <Ul> <Li> Swiss </Li> <Li> Syrian - Lebanon (Display) </Li> <Li> Turkish </Li> <Li> Ukrainian </Li> <Li> Welsh </Li> <Li> Yugoslav </Li> </Ul> </Td> </Tr> </Table>

How long did it take to build the cathedral of learning