Regin Schwaen & Nick Wickersham

School of Design, Architecture and Art. North Dakota State University, United States of America
regin.schwaen@ndsu.edu & nicholas.wickersham@ndsu.edu

PANTHEON 2.0 or: Finding a Copy of the Original Drawings for a Temporary Tower and Formwork of the Dome and then Rediscovering them Again Extrapolating the Method of Constructing the Dom

The Pantheon is double. It is two in one. When tourists visit the Pantheon in Rome, they are looking at two buildings at the same time because most of the formwork and structural support for the concrete is still in place today. After craftsmen cast footings and were certain that the foundation walls were set in their exact positions, the interior and the exterior walls of the rotunda were defined by lines of bricks. Then the space between the two lines was filled with concrete and additional aggregate. Scholars describe the Pantheon as a brick-faced building, but this is not correct. The bricks are the formwork for the concrete, and it is still in place today, making the Pantheon two buildings in one. It is double. The concept of the Pantheon is developed from the interplay of squares and circles. It arises from two squares that share a side, one for the portico the other for the rotunda. The circular aspect of the rotunda’s interior is established by embracing the corners of the second square. Other less obvious complex arithmetic relationships also exist between
the seven niches of the rotunda and the 140 perspective coffers that decorate the interior of the dome. In a previous paper we speculated on the use of a temporary tower
system to support formwork for the dome area above the coffers.1
During the research for this paper, we found remarkably detailed historic drawings of the Pantheon. These 17th and 18th century drawings depicted ornamentation panels in the floor of the portico. Unfortunately, those ornamentations in all probability no longer exist. Studying these geometric figures of the floor of the portico, we found them to be very similar to the drawings we had made in the exploration of geometric possibilities for positioning a temporary form supporting tower in the centre of the rotunda. We believe the figures on the portico floor are reflective of methods employed in the construction of the dome and that the contractor outlined and embedded those in the floor 1900 years ago.
If correct, this is a novel finding. These historical drawings are all but forgotten and today only the outlines on the floor are apparent where the ornamentation panels once were. In the following paragraphs and drawings, we will examine how these forgotten geometric patterns might inform the construction of temporary support structures required for casting the apex of the dome of the Pantheon.
We believe that the ornamentation has embedded information for other elements as well. We include superimpositions in where we imagine that some panels that surround the drawings for a temporary tower perhaps are geometric principals for various elements of the structure and its size. We therefore include speculations on the context and proportional relation of the Pantheon to the Mausoleum of Augustus and Campus Martius. Today we find ourselves in a sea of thorough recordings that begins with Andrea Palladio, Antoine Desgodetz, Giovanni Battista Piranesi, Francesco Piranesi followed by many elaborations and publications such as Pier Olinto Armanini, Eugène Viollet le Duc, Kjeld de Fine Licht, William L. MacDonald, Friedrich Rakob, Mark Wilson Jones, George R. H. Wright and many others but in modern times the notion of building and scaffolding and other elements that pertain to the construction of the building is worth a revisit.

Keywords: formwork drawings; perspective coffer; Pantheon monument; temporary scaffolding tower; unreinforced concrete dome.