Physorg.com: "Historian John Nicols and physicist Robert Zimmerman have joined with architects James Tice and Virginia Cartwright to lead a group of scholars and students seeking to create a replica of the Horologium / Solarium of Augustus, a 60-foot granite obelisk erected at Heliopolis in the seventh century B.C. by Psammetichus II and brought to Rome by Augustus in 10 B.C. The obelisk was to be used as the 'gnomon' (the staff against which the shadow is projected from the sun to the ground) of a new solar calendar and 'clock.'
'It was a momentous event in the history of time, for it marks the revolutionary shift in time-keeping from the lunar to a solar-based system we now use,' said Nichols, who specializes in ancient history and the history of science.
'What makes the Augusti solarium so significant is that it was the first attempt in the West to display the hours of the day and the days of the month - as well as the months and the seasons - in an astronomically correct way. Previous calendars were based primarily on the lunar cycle which created a 355-day year.'
The obelisk was toppled in late antiquity, rediscovered in the Renaissance, and set up again - without the face of the dial - in front of the Italian Parliament in Rome. About 20 years ago, a team of German archaeologists located the 'face' of the sun, which measures roughly 300 by 200 feet, 18 feet below the current street level of Rome. Nicols said the scholars and students hope to lay out the gnomon, or obelisk, for the solarium on a half-scale model. Hours of the day, days of the month, and the seasons will all be clearly marked."
I met with Professor Tice about participating in the Nolli Map Project. I didn't realize he was also working on this endeavor. When it is completed, I'll have to grab my digital camera and go have a look!
See the project website: http://darkwing.uoregon.edu/~klio/solarium/images.htm