Negative space enclosed by letterforms is called counters.
Negative space is white space that letters such as O or D have (enclosed white space within the letter). Well, in typography, that white/negative space is called a counter, or aperture, or inner space, or enclosed space.
Around the mid 1940s in the united states
Well the dome was actually based off the domes used by the romans, byzantines, and persians, but the dome itself is called a qubba.
