in the space between the mensa and the predella. A guard about three inches wide (plinth), made of wood suitably painted, or of polished metal, may be placed at its lower extremity, resting on the predella, so as to prevent its being easily injured by those who move about the altar. Regularly, the colour of the antipendium should correspond with the colour of the feast or office of the day (Cærem. Episc., I, xii, 11). The Missal (Rubr. Gen., xx) says this should be the case quoad fieri potest, by which the Missal does not imply that one colour may be used ad libitum for another, but that the more precious antipendia of gold, silver, embroidered silk, etc., in colours not strictly liturgical, may be used on solemn occasions, although they do not correspond in colour with the feast or office of the day (Van der Stappen vol. III, q. 43, ii). The following are exceptions to the general rule: (1) When the Blessed Sacrament is publicly exposed the antipendium must be white, whatever the colour of the vestments may be. If, however, the Exposition takes place immediately after Mass, or Vespers, the antipendium of the colour of the Mass, or Vespers, may be retained if the celebrant does not leave the sanctuary between the Mass, or Vespers, and the Exposition; but if on these occasions he vests for the exposition outside the sanctuary, the antipendium if not white must be exchanged for a white one. (2) In solemn votive Masses the colour of the antipendium must be that of the vestments. In private votive Masses (missæ lectæ) its colour corresponds to that of the office of the day. In private votive Masses celebrated solemnly, i.e. with deacon and subdeacon, or in chant (missæ cantatæ) it is proper that its colour correspond with that of the vestments. (3) During a solemn Requiem Mass at an altar in the tabernacle of which the Blessed Sacrament is kept, the black antipendium cannot be used (Cong. Sac. Rit., 20 March, 1869), but one of a violet colour should take its place. The Ephemeides Lit., (XI, 663, 1897), states that this decree was revoked by a subsequent decree of the same Congregation, 1 December, 1882. It seems strange that the former decree is retained in the latest edition of the Decrees of the Cong. Sac. Rit. The latter decree is an answer to the question: Under these circumstances may the antipendium and the conopæum (cover of the tabernacle) be black? The answer seems to pass over the antipendium, and merely says: "At least the canopy over the tabernacle should be of a violet colour". The antipendium need not be blessed.
Altar-Horns.—On the Jewish altar there were four projections, one at each corner, which were called the horns of the altar. These projections are not found on the Christian altar, but the word cornu ("horn") is still maintained to designate the sides or corners of the altar. Hence cornu epistolæ and cornu evangelii mean the epistle and gospel side of the altar respectively; cornu anterius and cornu posterius evangelii or cornu dexterum anterius and dexterum posterius mean respectively the anterior or posterior corner of the altar at the gospel side.
Altar-Lamp.—In the Old Testament God commanded that a lamp filled with the purest oil of olives should always burn in the Tabernacle of the Testimony without the veil (Exod., xxvii, 20, 21). The Church prescribes that at least one lamp should continually burn before the tabernacle (Rit. Rom. iv, 6), not only as an ornament of the altar, but for the purpose of worship. It is also a mark of honour. It is to remind the faithful of the presence of Christ, and is a profession of their love and affection. Mystically it signifies Christ, for by this material light He is represented who is the "true light which enlighteneth every man" (John, i, 9). If the resources of the church permit, it is the rule of the Cærem. Episc. (1, xii. 17) that more than one light should burn before the altar of the Blessed Sacrament, but always in uneven numbers, i.e. three, five, seven, or more. The lamp is usually suspended before the tabernacle by means of a chain or rope, and it should hang sufficiently high and removed from the altar-steps to cause no inconvenience to those who are engaged in the sanctuary. It may also be suspended from, or placed in a bracket at the side of the altar, provided always it be in front of the altar within the sanctuary proper (Cong. Sac. Rit., 2 June, 1883). The altar-lamp may be made of any kind of metal, and of any shape or form. According to the opinion of reputable theologians, it would be a serious neglect, involving grave sin, to leave the altar of the Blessed Sacrament without this light for any protracted length of time, such as a day or several nights (St. Lig., VI, 248). For symbolical reasons olive oil is prescribed for the lamp burning before the altar of the Blessed Sacrament, for it is a symbol of purity, peace, and godliness. Since pure olive oil, without any admixture, causes some inconvenience in the average American climate, oil containing between 60 and 65 per cent of pure olive oil is supposed to be legitimate material. Where olive oil cannot be had, it is allowed, at the discretion of the ordinary, to use other, and as far as possible vegetable, oils (Cong. Sac. Rit., 9 July, 1864). In case of necessity, that is, in very poor churches, or where it is practically impossible to procure olive or vegetable oils, the ordinary, according to the general opinion of theologians, would be justified to authorize the use of petroleum. We are of the opinion, however, that there are but few parishes that can claim this exemption on the plea of poverty. Gas (Ephem. Lit., IX, 176, 1895) and electric lights (Cong. Sac. Rit., 4 June, 1895) are not allowed in its stead. The Cærem. Episc. (ibid.) would have three lights burn continually before the high altar, and one light before the other altars, at least during Mass and Vespers. Before the Blessed Sacrament, wherever kept, a lamp should be constantly burning. Our bishops have the power of granting permission to a priest, under certain circumstances, to keep the Blessed Sacrament in his house. In such cases, by virtue of Faculty, n. 24, Form. I, the priest may keep it without a light, if otherwise it would be exposed to the danger of irreverence or sacrilege. For the same reason we believe It may be kept also in the church without a light during the night.
Altar-Lantern.—Lanterns are used in churches to protect the altar candles and lamp, if the latter for any reason, such as a draught, cannot be kept lighted. They are of perforated metal-work or set with crystals. They are used also to accompany the Blessed Sacrament when carried from one altar to another in the church, or when It is carried as Viaticum to the sick. In the former case the lanterns are attached to the top of high staves; in the latter, a ring is fastened to the top as in ordinary lanterns, and they are carried in the hand of a cleric or an assistant.
Altar-Ledge.—Originally the altar was made in the shape of an ordinary table, on which the crucifix and candlesticks were placed. By degrees, behind the altar a step was introduced, raised slightly above it, for candlesticks, flowers, reliquaries, and other ornaments. This step was called the altar-ledge. Later the tabernacle was added as a stationary appends of the altar and at its sides and behind it other steps were placed. They are sometimes called degrees or gradini. The front of these steps was sometimes beautifully painted and decorated. The gradini of Brunelleschi's church of Santo Spirito, Florence, display beautiful miniature groups of subjects from the Passion of Christ.
