Throughout the Great Workroom, which has no internal walls, the thin, white dendriform columns rise to circular "lily pad" tops that form the ceiling, with the spaces between the circles consisting of skylights made of Pyrex glass tubing. At the corners, where the walls usually meet the ceiling, the glass tubes continue up and over and connect to the skylights, creating a clerestory effect and admitting a soft light. The Great Workroom is the largest expanse of space in the building, and was intended for the secretaries of the Johnson Wax company, with a mezzanine for administrators.