There is a chanted blessing of the candle, a sort of mini Exsultet, which puts the Easter vigil ceremonies into a context. And Phos Hilaron is the evening hymn that balances the morning hymn Gloria in excelsis. So there's something else that could benefit from more context.

Maybe some document (the GILH, perhaps?) allows for adding a lucernarium rite.

The version given in Worship III presents the lucernarium as an alternative to the usual beginning of Vespers ("O God, come to my assistance", etc., and "Glory to the Father...").

Lucernarium, the evening service of light, has an ancient and, at times, elusive history. Before the sixth century, the offices of Evening Prayer (Vespers) and Night Prayer (Compline) were combined into one evening service, Lucernarium. This was a service of light wherein the candles in the church were lit—both for practical and symbolic purposes. There exists a fourth century hymn entitled Ad Incensum Lucernæ, which was probably composed for the office of Lucernarium. It was at this evening hour that incense was burned, symbolizing prayers rising towards Heaven. In antiquity, the term was also applied, at times, to the act of bringing a light into the room where the family was gathered together, especially the bringing of a lamp to the table at which the family was seated for the evening meal. For Christians, this light was a symbol of Christ. Following the sixth century, elements from Lucernarium were taken to make Evening Prayer and Night Prayer as separate hours; however, a sort of Lucernarium still exists in the Mozarabic and Ambrosian Rites.

In the sixth century Irish Antiphonary of Bangor, Vespers is called the hora duodecima, which corresponds to six o’clock in the evening, or the hora incensi, or again ad cereum benedicendum. The hora incensi recalls the custom of burning incense at this hour, while at the same time the candles were lighted. The term ad cereum benedicendum reminds us that the ceremony of lamp lighting at Vespers was symbolic and very solemn. Hence at some point after or around the sixth century, Lucernarium was split into the separate hours of Vespers and Compline.

A form of Lucernarium was taken over into the liturgy of Easter Eve from earliest times, only to receive considerable embellishment in succeeding centuries. In the Diary of Egeria the Pilgrim, written around 385 A.D., Egeria mentions the custom of a liturgical ceremony of light on Easter Eve held in church as part of the vigil service as she saw it on her pilgrimage to Jerusalem. She remarks with surprise that the light is not brought into the chapel of the Resurrection from outdoors, as happened to be the case in her homeland of Spain, but from another chamber in the grotto. We learn, moreover, that in Spain the fire for the ceremonial light was struck from flint in front of the church edifice. This fourth century service in some way resembled the very solemn rite of Lucernarium that we have now at the Easter Vigil. Even today’s modern Roman Missal calls the solemn beginning of the Easter Vigil Lucernarium.

Finally, St. Basil also speaks of a hymn being sung at the moment when the torches were lighted—doubtless the famous third century Greek hymn Phôs Hilaròn (or, in Latin, Lumen Hilare), rendered in English as O Gladsome Light or O Radiant Light, O Sun Divine. St. Basil characterized this hymn as being “old” in his own day and thus could be one of the oldest and earliest hymns in existence, notwithstanding some Scriptural “hymns” or canticles.

On a personal note, I have a copy of an order of Lucernarium currently in use by the Order of Preachers (the Dominicans) in the Province of St. Albert the Great (Central Province) in the United States of America. The service consists of: (1) An introductory verse; (2) an evening hymn; (3) a prayer of thanksgiving for light; (4) incensation with the singing of Psalm 141 with an antiphon (or "another suitable song"); and (5) a final prayer.

I checked "Dictionary of the Liturgy" by Jovian Lang, OFM, 1989. Under "Lucernarium" it gives the example of the Easter Vigil, but does not indicate any other current use of the ceremony in the Roman rite. Fr. Lang says there is a "strong contingent" of liturgists working to revive its use in Evening Prayer.

The 'Phos Hilaron' appears in the Customary of Our Lady of Walsingham.

Thank you to everyone who has commented on this thread!

@RevAMG: Fascinating! Of course I know that Evensong is an amalgamation of Vespers and Compline, but I did not know that those two offices originated as a single service!

There is no Lucernarium in Vespers of the modern Roman Rite, which IMO is a shame if for nothing other than the absence of Phos Hilaron from Vespers. I have seen it included in Vespers services nonetheless.

That said, strictly speaking, just as there is nothing that prohibits a recessional hymn at the end of Mass, there would seem to be nothing wrong with “prefixing” a Vespers service with a Lucernarium?

The England&Wales book seems to be still available the structure is attached.

RevAMG: Could you share the lucernarium from the Dominican service? I'd love to see it!

Very interesting, thanks. I pray the current Liturgy of the Hours in Gregorian chant using Les Heures Grégoriennes and Antiphonale Romanum I and II, plus Liturgia Horarum (for the Office of Readings, which I typically sing recto-tono). Although I find the LOTH well-tailored to my lifestyle, one beef I have is "Vesperettes". I find Vespers too short (especially week III when the mid-day "minor" hour has more psalmody than Vespers, one of the two "major" hours), not to mention I find the NT Canticles not anywhere near being canticles with often syncopated psalmody that clearly was never made to be chanted, but that's another story.

So I've been trying to "beef up" Vespers if you will. I did the same to Lauds by adding the ritual for reading the martyrology at the end, plus I say the Invitatory with Lauds as I usually do the OOR the previous evening by anticipation. I was looking for ways to enhance Vespers as well. Typically I could chant Vespers, at a "normal" pace, with silences, in about 18 minutes. I've added a ritual lighting of the candles before, and slowed down the pace of psalmody and the length of the psalmody and have gotten it to about 23 minutes now. Maybe with a proper lucernarium ritual I can get it to 25-30 minutes. Or maybe I could just go back to the Monastic Office and play "juggle lots of books". I do have a small oratory I use to pray the Divine Office.

I know a lucernarium was considered when developing the LOTH; see "From Breviary to Liturgy of the Hours" by Stanislaus Campbell. Nothing came of it. Too bad. I can hardly see the attraction for the laity of dragging them out of their warm abodes for Vespers on a cold winter evening, for a 20 minute service, assuming one can find a place that celebrates Vespers publicly!

Ora

I get the impression that the Lucernarium was a "good idea" that someone had during a meeting. I've seen it in various liturgical books, but never actually heard of it being done in practice; sort of like form 'B' of the Penitential Act at Mass (many do 'A', most do 'C', none do 'B').

I can hardly see the attraction for the laity of dragging them out of their warm abodes for Vespers on a cold winter evening, for a 20 minute service, assuming one can find a place that celebrates Vespers publicly!

Which is why when we started doing Sunday Vespers we added stuff from the BCP(!) to the back end of it after the dismissal: Prayer for All Sorts and Conditions of Men, Prayer for the Clergy, etc., and a Hymn from the hymnal (the actual Vespers Hymn was the Gregorian books); then the Marian Antiphon with its Verse and Collect as found in the old books. This stretched it to about 25 minutes. (I printed out weekly booklets)

Then we eventually "bit the bullet" and decided to switch to the Traditional Office and buy some Vesperales (Latin & English Translation): It lengthened it to about 50 minutes.

One thing I like about the Liturgia Horarum is the addition of the New Testament Canticle on Sundays (from the Apocalypse or 1 Peter, depending on the Season). My ideal Vespers would be Pss. 109(110), 110(111), 111(112), 112(113), and the Canticle: with, obviously, the Magnificat, etc.

Two official ways of lengthening public Vespers :
GILH§46 suggests a longer reading from the Office of Readings, or from Mass (e.g. from the day in a different cycle), and optionally a homily on the reading.
The instruction on Worship of the Eucharist outside Mass suggests having Vespers before the Blessed Sacrament exposed, and ending with Benediction.