– The layer of tesserae.
A very innovative technique of applying tesserae in the upper walls of the nave was the tilting and setting gold and silver pieces at sharp angles. This procedure enhanced the reflection of light that is coming through the windows that separate the angels, and thus, increasing the amount of light that goes downward in the direction of visitors.
Over the centuries, many tesserae of the angel mosaics were lost. Therefore, restorers are filling in these lost parts with a layer that they engrave to give onlookers an idea of how they appeared before.
2) Mosaics in the middle part of the southern wall represent the names of Jesus’s ancestors according to the Gospel of St Luke (ch3: 23-38) while the mosaics in the middle part of the northern wall represent the genealogy of Jesus according to the Gospel of St Matthew (ch1: 1-7). Today, only seven of the ancestors can be seen with their names written in Latin.
Moreover, the southern and northern walls contain texts in Greek and Latin surrounded by geometrical shapes separated by acanthus leaves, candlesticks and incense burners. These texts represent decisions of the Ecumenical and local synods.
The restoration work taking place at the Basilica of the Nativity in Bethlehem - photo courtesy Latin Patriarchate of Jerusalem