What does this mean?
The tympanum of St. Trophimus takes up the theme of biblical tetramorph evoking the vision of Ezekiel and the Apocalypse of St. John, then a symbol of the four Evangelists, it shows a triumphant Christ and dispenser of justice, seated, holding the Bible on his lap and blessing with his two fingers of his right hand raised. It is surrounded by the classic symbols of the four evangelists: a winged lion for St. Mark, an angel (or a winged man) to St. Matthew, St. John for an eagle and a winged bull for St. Luke. The two evangelists at the bottom of the eardrum Mark and Luke, who unlike Matthew and John have not known Christ, do not watch the son of God.
This motif is common in Roman art as can be seen for example in the eardrums of Charlieu Abbey, Saint-Gilles, of Our Lady of Embrun and Saint-Benoit-sur-Loire.
On the archivolt are represented angels of judgment and angels in adoration.
Have you looked up the unfamiliar words?
http://dictionary.reference.com/browse/tympanum
Sometimes pictures help.
http://www.google.com/search?q=tympanum&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=vpHjT_H1KoOc8QSyz5iGCA&ved=0CGoQsAQ&biw=711&bih=453
This passage is describing the meaning behind the tympanum of St. Trophimus. To understand its meaning, we need to break it down:
- The tympanum is the semi-circular or triangular decorative wall surface above a door. In this case, it refers to the one on St. Trophimus.
- The biblical tetramorph refers to the representation of the four Evangelists in a symbolic way. It evokes the visions of the prophet Ezekiel and the book of Revelation or Apocalypse of St. John.
- The four Evangelists are Matthew, Mark, Luke, and John, who wrote the Gospels in the New Testament.
- The triumphant Christ refers to Jesus Christ in a victorious and exalted state, often depicted as seated and holding the Bible.
- The dispenser of justice means that Christ is seen as the one who administers justice.
- The depicted Christ is shown blessing with his right hand raised, using two fingers.
- The symbols surrounding Christ represent the four Evangelists: a winged lion for St. Mark, an angel or winged man for St. Matthew, an eagle for St. John, and a winged bull for St. Luke.
- The two evangelists at the bottom of the tympanum, Mark and Luke, are depicted but not shown watching Christ as they did not personally witness or know him during his earthly life.
This motif of depicting the four Evangelists and Christ is common in Roman art, as mentioned in other examples like Charlieu Abbey, Saint-Gilles, Our Lady of Embrun, and Saint-Benoit-sur-Loire.
On the archivolt, which is the curved molding above the tympanum, there are representations of angels of judgment and angels in adoration.