Details of the Design
The 16 inner ribs were joined together by horizontal arches, herringbone patterns (coming from Roman construction) were used to lighten and strengthen the top tier. The basic goal was to maintain a pyramidically oriented shape which would diminish in width as well as thickness upon reaching the lantern, so that the lantern would cap the ribs and serve as a stopper with its weight. A type of flying buttress was also used to balance the weight of the lantern. Although a typical Gothic buttress would have been unacceptable, Brunelleschi was able to interpret the idea in such a way to make it softer and more modern.
Not only is the Dome an example of Brunelleschi combining ancient, medieval Gothic, and modern Renaissance ideas, it is also important to note that he invented the unique method of building for this particular challenge, including mechanics, tools, and the most efficient routes. All this from a man who trained as a goldsmith.