The illumination of monuments doesn't ordinarily attract national headlines. But in Italy, a project to light 22 monuments in the 120,000-sq.-yd. (100,000-sq.-m) central archaeological area of the Roman Forum has captured the imagination of the nation.

The Forum was originally a marshy valley bottom used as a cemetery, but the first Etruscan king made canals from the Cloaca Maxima stream, dried the area, and had it paved. It then became a large square for meetings. Soon, the first important buildings and temples were built and The Forum became the religious, civic, and commercial center of pastoral, royal, and republican Rome. Excavations down to what was ground level in Julius Caesar's day have brought to light an incredible number of monuments of great archaeological importance, even if some are only fragments of the original buildings.

The Forum is being illuminated by the Unità Operativa Illuminazione Pubblica (UOIP), the public lighting department of the Eternal City's electricity board (ACEA). UOIP has also designed the majority of the architectural lighting for Rome's other monuments, including the Largo Argentina archaeological area, the Nymphaeum of Minerva Medica, the Aurelian Walls, and the Diocletian Baths. LD Remo Guerrini of the UOIP says the Forum is part of a larger campaign, due for completion by 1999 at a total cost of more than $10 million.

"Apart from the practical difficulties involved in lighting so many different structures, it must be remembered that visitors can enter the area for guided evening visits, so there was no point in the monuments being lit in such a way as to makethem only viewable from outside the area," Guerrini says. "The work has also been hindered by the scaffolding around some of the monuments that are being restored, which prevents them from being viewed completely and also means that they can't be entirely lit. This was the case with the Septimus Severus arch, the right-hand side of which is completely covered in scaffolding."

There are also numerous laws, enforced by the Ministry of Cultural and Environmental Property and Rome's Archaeological Service, that must be obeyed when installing lighting systems in historically vital areas. Factors that must be considered include the depth of excavation, where allowed, which varies from 30 to 50cm, and the method by which holes or chases have to be closed, with mortar made up of pozzolan, lime, and in some cases "coccio pesto" (crushed earthenware). Even chases in walls that are not archaeologically important have to be filled to perfectly match the pre-existing construction.

"The problem of laying cables in areas where excavation isn't allowed was solved in some instances by using a hollow guide/barrier rail able to hold four-core cable (each core with a 3mm diameter) plus a suitable ground cable," Guerrini says. "At the Basilica of Aemilius and the Basilica of Julius, the valuable original paving made fixture installation on the ground impossible. All this was taken into consideration during planning; where we knew there were archaeological structures that couldn't be tampered with, we designed so as to avoid work grinding to a halt at a later stage."

Philips Lighting has acted as consultant on the project, examining the designs and assisting during lighting tests implemented when work on the various systems reaches an advanced stage. The company was also technical sponsor for the Forum lighting, and supplied approximately 85% of the 520 instruments and lamps used.

The monuments were built with bricks, marble, travertine, and in some cases tuff. A different kind of lighting was used for each material. There are instances where a combination of materials was used for one building; for example, the Temple of Antoninus and Faustina (built by Antoninus Pius in honor of his late wife Faustina, and consecrated as a church in the 11th century) has its base in tuff, 50'-high (15m) columns in cipolin marble, lintels in travertine, and a brick facade for the church, which filled most of the temple's area. The lighting is cued off the construction: The system highlights the marble with the white light of MasterColor(TM) discharge lamps (3000K), the tuff with the "warmer" white of White SON lamps (2500K), the facade with high-pressure sodium lamps (2100K) and the lintels with more white light, this time from the new MasterColor CDM metal-halide lamps (4200K, color rendering >90).

In other areas, White SONs were used for terracotta surfaces, MasterColors for lighting "holy" vines, fig and olive trees, as well as marble, and high-pressure sodium lamps (2100K) mounted in Philips SNF210 AS floodlights for other temple and basilica facades. The fixtures used with the White SON and MasterColor lamps were Philips Decofloods and the models varied according to the application: rotational symmetrical units were used to light the columns and asymmetric models for horizontal lighting. Says Guerrini, "Decofloods are extremely compact fixtures, which facilitated instrument placement; you don't see them either day or night. The entire area, incidentally, was illuminated with a total power of 80kW, just 27 times what's used in a normal apartment--thanks to the high efficacy and rendering of the fixtures used."

Of the monuments being lit, the most complicated was without doubt the huge Basilica of Maxentius (also known as the Basilica of Constantine, as its construction was begun by the former in 306 A.D. and finished by the latter). If the large halls with their coffered ceilings and 60'-high (18m) pilasters had been lit from the front in the traditional manner, their charm and the perception of the decorative architectural elements would be lost.To avoid this, the lighting was designed using highly asymmetric units, such as the SNF210 AS fixtures installed approximately 6' (1.8m) from the inner wall of the halls and about 4.5' (1.4m) from the base of the pilasters. The asymmetric light beams wash the surfaces, highlighting the irregularity of the material and, thanks to the shadows formed, drawing visitors' attention to the large octagonal caissons in the basilica's roof. This system also ensures that light spill is avoided.

The monuments were all up-lit, so the fixtures were installed close to the buildings and in the temples of Antoninus and Faustina, Saturn (built 498 B.C., restored 42 B.C.), and Vespasian and Titus, on the raised inner levels. No fixtures were installed more than 30' (9.1m) from the buildings.

A series of Ruud NS-Micro floodlights, fitted in a custom-built rail mounted along the Via Sacra (Holy Way), were used both to keep visitors from wandering off the path and as a conduit for the cables, which could not be laid underground for archaeological reasons. These were supplied by the US firm's Italian agent, Florence's Advanced Lighting Technology, one of the country's best-known firms in the monument and architectural lighting field.

Legend has it that the Via Sacra is the road along which Romulus and Titus Tatius returned following the alliance between the Romans and Sabines, and each month religious ceremonies with sacrifices were held there. The Ruud units (also fitted with MasterColor lamps) were chosen for their technical characteristics, high corrosion resistance, and extremely small size, a key factor in their choice for mounting in the rail. Ground-recessed Castaldi Illuminazione Power Disk luminaires were also used, as Philips does not have this type of instrument in its range. ACEA decided not to use filters anywhere, leaving effects to the choice of the correct lamp and the natural beauty of the colors of the original building materials.

"As far as fixture protection is concerned," Guerrini says, "all are to IP65, which protects them against the entry of solid or liquid material, as required by CEI norms. As far as the risk of tampering goes, however, the few fixtures in areas completely open to the public have no such protection, as it was decided to avoid adding further technology, which would have made our 'intrusion' even more cumbersome and the fixtures an eyesore. We hope the public will not damage the instruments and that this will contribute to making people more sensitive toward the upkeep of areas that are part of our common heritage."

Some of the most important monuments in this project include the columns of the Basilica of Aemilius (the only remains of the Republican basilicas); the Temple of Vesta, built in 191 A.D. on the site of a clay-and-wattle hut that housed the Sacred Flame (three columns remain of the 20 that supported the conical roof through which escaped the smoke of the Vestal Virgins' fire); the 50'-high (15m) Arch of Titus, built in Greek marble on the slopes of the Palatine Hill in 81 B.C. by the emperor Domitian in memory of the victorious campaigns of his brother Titus against the Jews; and the Temple of Castor and Pollux, originally built in 484 B.C., where the Roman Senate often met. Another impressive monument is the 43'-high (13m) Phocas Column, the "newest" monument in the Forum, dedicated to Phocas, the Byzantine emperor who donated the Pantheon to Pope Boniface IV.

Regarding future plans, Guerrini says, "A new lighting system is on the cards for the Colosseum, but we don't yet know when or by whom. Other buildings for which ACEA is studying lighting projects for the Jubilee of the Roman Catholic Church in 2000 include the main basilicas and numerous churches involved in the celebrations, the Baths of Caracalla and the Domus Aurea, as well as Villa d'Este and Villa Adriana in Tivoli." The rebirth of the Roman Empire has only just begun.

Scots-born Mike Clark, a Rimini, Italy-based journalist specializing in lighting and related technology, can be contacted at mclark@rimini.com.