Solarium Augusti

The Solarium Augusti, the largest sundial the ancient world has known, [Edmund Buchner (1976). "Solarium Augusti und Ara Pacis", "Römische Mitteilungen" 83: 319-375; "Die Sonnenuhr des Augustus: Kaiser Augustus und die verlorene Republik" (Berlin) 1988.] was erected in Rome by Emperor Augustus, with a 30-metre Egyptian red granite obelisk that he had imported from Heliopolis. In a triumphant demonstration of Ptolemaic Egypt's subordination to Roman military might the obelisk was employed as a gnomon that cast its shadow on a marble pavement inlaid with a gilded bronze network of lines, by which it was possible to read the time of day according to the season of the year. The "solarium" was dedicated to the Sun in 10 BC, shortly after Julius Caesar's calendar reform. It was the first solar dedication in Rome. [Robert E. A. Palmer, "Studies of the Northern Campus Martius in Ancient Rome" "Transactions of the American Philosophical Society" New Series 80.2 (1990:1-64) p. 21, commenting on the "Acta" of the Secular Games.]

The Solarium Augusti was integrated with the Ara Pacis, aligning with Via Flaminia, in such a way that the shadow of the gnomon fell across the center of the marble altar on 23 September, the birthday of Augustus himself. The obelisk itself was set up to memorialize Augustus' subordination of Egypt to the control of the Roman empire. The two monuments must have been planned together, in relation to the pre-existing Mausoleum of Augustus, to demonstrate that Augustus was "natus ad pacem", "born to bring peace", that peace was his destiny. [Peter J. Holliday, "Time, History, and Ritual on the Ara Pacis Augustae" "The Art Bulletin" 72.4 (December 1990:542-557) p. 554.] "The collective message dramatically linked peace with military authority and imperial expansion." [Alan K. Bowman, Edward Champlin, Andrew William Lintott, "The Cambridge Ancient History" 1996:194, reporting Buchner's meticulous survey published in Buchner, "Horologium solarium Augusti: Vorbericht über die Ausgrabungen 1979/80" "Römische Mitteilungen" 87 (1980:355-73).]

Pliny the Elder [Pliny's Natural History, XXXVI.72-73] remarked that in the course of time it had become incorrect, and offered several explanations for the shift. The obelisk was illustrated, supported by a reclining figure, on the base [Now in the Vatican Museums; [http://www.bluffton.edu/~sullivanm/romanpius/romanpius.html illustrated by Dr. Mary Ann Sullivan] ] of the Column of Antoninus Pius; it was still standing in the eighth century, but was thrown down and broken, then covered in sediment; it was rediscovered in 1512, but not excavated. In a triumphant rededication, the obelisk, now one of the most prominent obelisks of Rome, was re-erected in Piazza di Montecitorio by Pius VI in 1789. [ [http://penelope.uchicago.edu/Thayer/E/Gazetteer/Places/Europe/Italy/Lazio/Roma/Rome/_Texts/PLATOP*/Obeliscus_Augusti.html Samuel Ball Platner and Thomas Ashby, "A Topographical Dictionary of Ancient Rome"] (London: Oxford University Press), 1929:366f, with William Thayer's additional notes]

Edmund Buchner excavated some sections of the calibrated marble pavement of the Solarium Augusti under the block of houses between Piazza del Parlamento and Piazza San Lorenzo in Lucina ("picture, right").

A broad context for the iconographic programme of which the Solarium Augusti is part is offered in Paul Zanker, "The Power of Images in the Age of Augustus" (University of Michigan Press), 1988.

Notes

External links

* [http://www.uark.edu/ua/metis2/zanker/zanker_txt2.html Paul Zanker, "The Augustan Program of Cultural Renewal (part two)] . The Solarium Augusti in the context of Augustan monuments.
* [http://www.uoregon.edu/~klio/solarium/solarium_project.htm Project to construct a full-scale replica on the campus of the University of Oregon, Eugene]
* [http://www.unicaen.fr/rome/visite3.php?action=biblio&langue=anglais&id=horologium&idMonu=17 "The Horologium of Augustus: a bibliography"]