Florence’s cathedral had a hole in the roof and the people didn’t know what to do with it. The hole was 150 feet across and 180 feet above the ground. The task seemed nearly impossible. The leaders of Florence announced that whoever could come up with an ideal dome would receive a prize of money and maybe even fame. Filippo Brunelleschi came up with the idea of having two domes inside of each other to get the support needed. He built the first part of the arch with stone and gradually used lighter materials towards the center so the pressure wouldn’t be so great. A few problems they ran into were ones such as, no lifting tools. Brunelleschi invented what is called a three-speed hoist which has pulleys and gears among other things. After Brunelleschi
