Click link for Rotunda math page

The Rotunda is the main building on the University of Virginia grounds. Thomas Jefferson made the Rotunda in 1826,
copying the Pantheon in Rome. The dome on top of the Rotunda has a library hidden in the dome.
In Dallas, Texas, S.M.U (Southern Methodist University) copied the Rotunda in 1915 and called it Dallas Hall.
external image DallasHall1.jpg

Math question: how many years earlier was the Rotunda built?