1. Section of a portion of the catacomb of St. Pontien at Rome; a well of water is still seen, which was used to administer baptism in the early periods of the church, from the first to the fourth century.
2. Plan of the place, with the staircase by which it is reached, and the canal which conducts the water.
3. Perspective view of the same; on the wall at the back is a fresco painting, representing the baptism of Christ.