Construction first started with excavating a foundation for the entire building, removing over 60, 000 cubic yards of dirt, digging in about 15 feet underground to lay the hard, gray concrete to form a ring. This strong foundation would set up not only the scaffolding for the workers, but also carry the weight of the buttresses used primarily to hold the concrete dome to be built on top. Each buttress is reinforced-concrete, about 3.5 feet thick, and 16 feet wide with a 109 feet radius and would support the construction of the dome later on. After the construction of the buttresses, the falsework for the concrete dome to lay on and harden was built, which finally allowed for the actual construction of the concrete
Construction first started with excavating a foundation for the entire building, removing over 60, 000 cubic yards of dirt, digging in about 15 feet underground to lay the hard, gray concrete to form a ring. This strong foundation would set up not only the scaffolding for the workers, but also carry the weight of the buttresses used primarily to hold the concrete dome to be built on top. Each buttress is reinforced-concrete, about 3.5 feet thick, and 16 feet wide with a 109 feet radius and would support the construction of the dome later on. After the construction of the buttresses, the falsework for the concrete dome to lay on and harden was built, which finally allowed for the actual construction of the concrete