from: David Magie (translator), The Scriptores Historiae Augustae (Cambridge, MA: Harvard University Press, 1980), vol. II.
p. 113: Then, when he held his first audience with the senate, he gave orders that his mother should be asked to come into the senate-chamber. On her arrival she was invited to a place on the consuls' bench and there she took part in the drafting--that is to say, she witnessed the drafting up of the senate's decree. And Elagabalus was the only one of all of the emperors under whom a woman attended the senate like a man, just as though she belonged to the senatorial order.
He also established a senaculum, or woman's senate, on the Quirinal Hill. Before his time, in fact, a congress of matrons had met here, but only on certain festivals, or whenever a matron was presented with the insignia of a "consular marriage"--bestowed by the early emperors on their kinswomen, particularly on those whose husbands were not nobles, in order that they might not lose their noble rank.
p. 149-51: He gave a naval spectacle, it is said, on the Circus-canals, which had been filled with wine, and he sprinkled the peoples cloaks with perfume made from the wild grape; also he drove a chariot drawn by four elephants on the Vatican Hill [The circus Vaticanus was constructed by Caligula at the north end of the Janiculum (the present site of the Church of St. Peter). Under Nero it was the scene of the tortures inflicted on the Christians; see Tacitus, Annals, xv.44. The context of the present passage, however, seems to indicate that it was not this circus that was the scene of Elagabalus' exploit, but the immediate vicinity, generally known as Vaticanum, where remains of tombs have been discovered; see O. Richter, Topographie d. Stadt Rom, p. 280 f.], destroying the tombs which obstructed the way, and he harnessed four camels to a chariot at a private spectacle in the circus.