These are the dimensions of the altar, according to a twenty-one-inch unit of measure.a The base is twenty-one inches high and twenty-one inches wide, with an outer curb measuring one and a half inches all around. This is the altar's height.
From the base at ground level to the lower ledge is forty-two inches; the lower ledge is twenty-one inches wide. The distance from the lower to the upper ledge is seven feet; the upper ledge is twenty-one inches wide.
The hearth is seven feet high, with four horns projecting upward from the hearth.
The hearth is twenty-one feet square; each side is equal to the others.
The ledge around the hearth is twenty-four and a half feet long by twenty-four and a half feet wide, a square. Its outer rim is ten and a half inches, and its base all around is twenty-one inches. Its ramp faces east.