Early architects did not have the means to construct a dome that would have the same grand appearance from both inside and outside the building until 1418 when an Italian architect named Filippo Brunelleschi conceived the idea of employing mathematical perspective to establish new rules of proportion and symmetry.
Brunelleschi's theory of perspective was developed from the fact that the apparent size of an object decreases with the increasing distance from the eye. This knowledge was used by Brunelleschi in the successful construction of the Cathedral of Santa Maria del Fiore in Florence, Italy.
His innovative plans included an inner hemispherical dome-within-a-dome. A second brick dome was to be placed on top and nine sandstone rings would then hold the structure together like a barrel. This was the first time that a dome created the same strong visual effect on the exterior as it did on the interior.
Brunelleschi's method of design and construction was employed in building California's State Capitol dome. The interior of the dome employs iron frame construction, allowing the majestic copper outer dome to rise above Capitol Park and the Sacramento skyline. From inside the building, the beauty of the Victorian detailing on the inner dome is visible in all its majesty.