Stephen's somber fantasy, in Proteus, of priests celebrating the Mass includes many odd details: Joachim as a celebrant, a choir answering his "basiliskeyed" stare with "menace and echo," and "jackpriests" (suggesting, Gifford notes, "priests in name only") who are "oiled and gelded." Perhaps the strangest is the image of servers "assisting about the altar's horns." Catholic altars do not have horns, but ancient Hebrew altars did. They seem to have been associated with the sacrifice of bulls and other animals, and Stephen seems to associate them with "the snorted Latin" of the priests. Later in the novel, Bloom thinks of the offerings burned on such altars.
Altars are mentioned throughout the Old Testament. The Hebrew word, mizbe'ah or mizbach, means a place of slaughter or sacrifice. Exodus describes altars of burnt offerings, specifying that "thou shalt take of the blood of the bullock, and put it upon the horns of the altar with thy finger, and pour all the blood beside the bottom of the altar. And thou shalt take all the fat that covereth the inwards, and the caul that is above the liver, and the two kidneys, and the fat that is upon them, and burn them upon the altar" (29:12-13). Bloom's phrase in Lestrygonians, "kidney burntoffering," indicates his awareness of this tradition.
The horns, by all accounts, were on the four corners of the altar. Exodus 27:2 says that they "shall be of the same" shittim wood as the altar itself, and everything covered with brass—suggesting that rather than attaching actual animal horns to the altar, workmen carved wood in that shape. Some passages (e.g., 1 Kings 1:50-53) indicate that fugitives could seek asylum by clinging to these projections.
Stephen's meditations on the sacrifice of bulls, and on priests snorting out the Latin of their rite, may bear some connection to his own identifications with oxen, as "Bous Stephanoumenos" and the "bullockbefriending bard." At the end of Scylla and Charybdis, he thinks again of altars with burnt offerings: "Laud we the gods / And let our crooked smokes climb to their nostrils / From our bless'd altars."