As architect A.D.Mason of Whitfield Partners writes in his article below, when designing the original Pillar Pierce would have chosen one of the classical orders for the column - Ionic, Doric, Corinthian etc - and then built it accordingly. We knew from the remains at Weybridge that he had chosen Doric but then a chance discovery led to a conundrum. When researching Pierce in the British Museum, David Bieda found a reference to a drawing held in a cupboard which had remained unopened for many years - indeed a locksmith had to attend to open it. Inside was Pierce's original drawing. However, Pierce's hand-drawn figured dimensions did not match the actual drawing and neither quite tallied with the dimensions of the remains of the column at Weybridge.
Once Mason had solved the conundrum of designing the new Pillar, he presented the Trust with an extraordinary 40-foot high paper version in sections. They became the full size templates from which the trainee masons would work.
For more detail, read below A.D. Mason's article Designing the Pillar and Foundations: