Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 7. The Church in the Catacombs. (Includes sections 82-87, loc. 15829-16152).
§ 84. Description of the Catacombs.
“The Roman catacombs are long and narrow passages or galleries and cross-galleries excavated in the bowels of the earth in the hills outside and around the city, for the burial of the dead” (Schaff 2014, Loc. 15952). They are multi-level and filled with tombs of different types. Schaff places the size of the Roman catacombs at “hundreds of miles, and the number of graves [by] millions” (Schaff 2014, Loc. 15963). These are separate cemeteries, probably originally associated with different congregations. Schaff observes the piecemeal nature of the artifacts and the challenges inherent in studying items which have been relocated (Schaff 2014, Loc. 15985). The use of different vessels is also largely a mystery.
§ 85. Pictures and Sculptures.
Painting, sculpture, and inscriptional remains provide a wealth of information (Schaff 2014, Loc. 16001). The more sophisticated works belong to the earlier period, before a general decline in the quality of artwork. The Christian symbolism can be identified throughout. Much of the sculpture is found on sarcophagi and date from the Nicene age and after (Schaff 2014, Loc. 16007). These are the burial places of wealthy and powerful people, many known in general historical sources (Schaff 2014, Loc. 16013).