Happy Independence Day to all my readers from the USA! In honour of the day, I have posted a photo I took a few years back during a visit to the United States Capitol building in Washington DC.
In the canopy of the rotunda is a fresco entitled “The Apotheosis of Washington” painted by the Italian-born artist Constantino Brumidi who studied under Antonio Canova in Rome before emigrating to the US in 1852. Brumidi was quickly hired as chief fresco painter of the Capitol in 1854, the cast-iron dome of which was completed by 1866. Unfortunately the artist slipped from the scaffolding while still working on the fresco in 1879 and died the following year, leaving his work in the rotunda unfinished.
The scene is full of the usual allegorical stuff, with George Washington playing the part of Zeus, surrounded by thirteen female figures each representing one of the original thirteen colonies. However, what particularly caught my attention at the time of my visit is the peripheral allegory of science, one of six vignettes around the perimeter of the dome. While on the right of the scene can be found the usual cast of worthies including Benjamin Franklin, Samuel Morse and Robert Fulton, discussing their various inventions with an interested goddess Minerva, behind her on the left is a small group of anonymous students learning the arts of surveying and drawing.
One of them uses what is clearly a plane table to take measurements for a land survey. Beneath him on the ground another youth appears to be receiving instruction in the art of masonry (or perhaps lithography?) with a robed teacher using a pair of dividers on a flat stone, just hidden behind the rim of the oculus but visible in an official photo on Wikipedia Commons.
It is instructive to compare the finished painting with Brumidi’s original study for the work, acquired by the Smithsonian American Art Museum in 2012. Here the youth working at the plane table is not holding a pen, but appears to be using some kind of instrument – probably an alidade – to make the survey. The figure on the ground is using a smaller pair of dividers on the stone. Next to him lies a T-square, which never made it into the final fresco.
I would be interested to know if these instruments were chosen to represent those in use in George Washington’s time, or if they were still considered everyday technology in the mid 19th century. Certainly even in the 1770s Thomas Jefferson had a very fancy theodolite by Ramsden which can be seen in his study at Monticello.
On the other hand, plane tables continued to be used for military surveying well into the 20th century. I have also been reliably informed that they remained the instrument of choice for the US Coast Survey’s recording of topographical detail until at least the end of the 19th century.