1To Thomas Jefferson from Arthur S. Brockenbrough, 2 December 1824 (Jefferson Papers)
Above you have the measurement of dome of the Rotunda above the steps—I also send you a Copy of the contracts for the Hotels that I propose making for your inspection and amendments. Measurement of the Dome from the top of the last step to the center of the Sky light 27 feet 5 inches. ViU : Thomas Jefferson Papers (Proctor’s Papers).