Plans for the Past

Plan of the Temple of Isis by J.C. Richard

The next step in order to build my 3D model of the Pompeian Iseum is to gather reliable measurements. The ideal condition would probably be going in situ and record the actual dimensions of the elements.

Even though I took extensive photographic documentation, when I went to Pompeii I had neither the equipment or the expertise necessary to undertake personally the operations. So, I looked for early records of the excavation and architectonical plans of the temple’s area. The old royal prohibition of documenting the site and the finds, makes not particularly easy to find detailed documentation. However, some of the authorised records have been very well preserved.

The first map I chose is the one drawn by Jean-Claude Richard, (aka the abbe de Saint-Non) in 1782 (Voyage Pittoresque ou Description des Royaumes De Naples Et De Sicile). The plan is very neat and includes the area of the ekklesiasterium in which I am particularly interested.

However, Saint-Non’s plan included no information about the height of the architectonical elements. Without at least one known measurement, it was impossible for me to start building a reliable model. So I kept looking for more resources. 

I was lucky enough to stumble on the digital archive of the Sir John Soane's Museum in London. Two of the documents in the Soane’s drawings collection were extremely interesting to my research: a plan of the Temple of Isis and a close up of the purgatorium. Promisingly, Soane included in his drawing a frontal elevation of the temple, as it looked like in 1779.

Plan of the Temple of Isis by J. Soane

I went to the museum to examine the drawings. It was two times exciting. First because I had the opportunity to handle beautiful and accurate documentation more than two hundreds year old. Secondly because the Soane Museum is itself a unique and wonderful place.

This is probably the right moment to thank again the Museum because when my supervisor and I explained them the topic of my research they kindly offered me an high quality digital copy of the drawings.

With the digital files I was allowed to make some experiments. First of all checking (using Adobe Illustrator) if the elevation drawn in the upper part of the plan shared the same scale of the plan. If so, I could have use it to derive the heights of some of the main elements of the temple. I have chosen two elements (the diameter of the columns and the length of the temple frontal footstep) and I have measured them in both the plan and the sketch of the elevation. As they matched, I had eventually a starting point for my model. Moreover, the source was one of the most famous and gifted architect of this country.

An additional bonus in Soane’s plan was the presence of a very accurate documentation of the distances between architectonical elements. The only drawback was the absence of the ekklesiasterium area, which is crucial to my research.

Few days ago, I was suggested to visit a very rich German digital resource on ancient architecture: Bildindex der Kunst und Architektur. I used “Isis” as key for my query and I found several relevant documents, mostly created by architect and engraver Francesco Piranesi.

Not only Piranesi produced an other plan of the Iseum, but he also drew very detailed elevations of the entire complex. Both plan and elevations were expressed in the same double unit (Roman Palms and Piedes de Paris), so it would have been relatively easy to derive the heights from there.

Eventually, I had three different plans: each of them interesting and rich in information, each of them created by a re-known and reliable source.