The construction of domes in the sixteenth and seventeenth centuries relied primarily on empirical techniques and oral traditions rather than the architectural treatises of the times, which avoided practical details. This was adequate for domes up to medium size, with diameters in the range of 12 to 20 meters. Materials were considered homogeneous and rigid, with compression taken into account and elasticity ignored. The weight of materials and the size of the dome were the key references. Lateral tensions in a dome were counteracted with horizontal rings of iron, stone, or wood incorporated into the structure.