History in Color: Maryland State House Dome Lessons

Paint analysis using fluorescence microscopy confirmed the accuracy of polychrome renderings of the 1790s. Neither Charles Willson Peale or other contemporaneous painters took what had been perceived in the 20th century as artistic license. Rather the physical evidence remaining in place beneath later paint after this 2011 restoration shows the use of a “poor man’s gold” technique for coloring the Maryland State House dome. This is in keeping with the stylish yet small Annapolis (“the Bath [England] of America” as it was known) which had long sought a bigger role for itself in the nation’s future.

The Maryland State House as it would have appeared from State Circle during the War of 1812. Image of Malcolm Dax
Maryland State House Dome rendered in Charles Willson Peale-informed 1790s color scheme

The 2011 Maryland State House Dome project highlights how the past was often more colorful than the chaste sepia tones we imagine. It also provides a great example of how improved paint analysis methods — specifically including fluorescence microscopy with protein staining techniques migrated from biology techniques — can elucidate more than just paint color history. It also allow the dating of paint layers based on their constituent ingredients. Knowing more about the paint formulations has the added benefit of allowing for selective stripping of some layers of overpaint while leaving historic evidence intact.

Cratering through the paint layers to get a first glimpse at the color history of the now white-painted dome. Clearly there was a long history of color in the earlier layers. And in fact the fluorescence microscopy suggests that a glazed effect with a lighter yellow beneath and a more golden glaze atop as this scraping exhibits was in fact the earliest paint history for parts of the Maryland State House dome.

Cratering through the paint layers to get a first glimpse at the color history of the now white-painted dome. 2010 John Greenwalt Lee

A repeated problem of restorations in the last few decades have been thinking in terms of paint as in a one-color solution as today. Historic finishes of this era were often achieved with glazes to give three-dimensionality to surfaces. Additionally many historic interiors have been painted out in seemingly odd color schemes during restorations that reverted to the base color for a wood graining scheme but overlooked the intended appearance that comes from base color, grain colors, and then a tinted glaze.

With fluorescence microscopy you can not only determine the colors but distinguish each layer even when the same color has been applied multiple times (often with dirt embedded between layers) and determine the type of coatings used (emulsion, oil, natural resin, latex etc.). Understanding the types and sequence of finishes can help in dating the coatings.

In fact the microscopy from a portion of the dome suggested this two-tone appearance and we recreated a sense of the likely intended original appearance in a sort of “poor man’s gold” glaze applied over a slightly flesh-colored base tone.

While more expensive analysis including SEM (scanning electron microscopy) and XRF (X-ray fluorescence) can help identify pigments can sometimes narrow the date range further, fluorescence microscopy can use the same mounted chip to provide significant information just based on reactions to several biological staining media.

Paint stratigraphy under normal and UV light both before (above) and after removing the latex overburden. Richard Wolbers, 2010.

Here the State House Dome paint stratigraphy viewed in UV light (right half) become distinct. In this instance, the top row of images show (latex) paints applied 10 years earlier that were thick and water trapping and which were removed during this project. The bottom row shows these layers of overburden removed leaving the well-adhered layers of historic paint intact.

Importantly, once the composition of paint layers is known, it can prove a very powerful tool in diagnosing paint failure due to incompatibility. For example have modern latex paints been applied over oil paints that were applied over early water-dissolvable emulsion paints, leading to differential swelling/contraction/breathability and therefore adhesion failures.

massive paint failure and wood deterioration only a decade after previous restoration (and on an easily accessible landing used to hoist the flag every day). 2010
Hard to imagine such massive paint failure and wood deterioration only a decade after previous restoration

The Maryland State House dates to 1779 and the current dome was completed in 1792 after storm damage to several earlier versions. This is the oldest continuously operating state house in the country and the Old Senate Chamber of the Maryland State House was where George Washington resigned his military commission in 1783 and, the following spring, where the Treaty of Paris was ratified, officially ending the Revolutionary War. At that time, Maryland’s State House was also functioning as the national capital. More on this history at Wikipedia.

There is little need for guesswork about how best to strip paint, even to remove selected layers only, when starting with fluorescence microscopy.

Using a Recyclean vacuum system to remove the top layers of incompatible paint after softening them with a gelled paint stripper

Balcony level view toward the Naval Academy showing a replacement copper ball for a missing unit.
Balcony level view from the dome showing a replacement copper railing cap that had been lost

The paint failure since the most recent work on the dome was largely the result of very heavy layers of latex being applied over 17 layers of oil. Latex is a fantastic way to strip earlier paints. This is largely due to water moving through latex paints, causing them to expand and contract. This movement exploits weakened oil layers as it tugs at the surface. The installation of caulking was also trapping water in the wood shingles that had previously been able to dry. In some cases this had caused shingles to swell with water and warp. Remember water is always moving through buildings, so it is generally best to not try to block water in historic buildings with sealants. The main focus of this project would be to remove the latex to get back into sound layers of oil paint, while re-establishing the original breathability of the dome system.

What we found in the process of looking for the physical evidence was that it also added to our understanding of the archival record. The paint evidence both confirmed contemporaneous annotations and connected the involvement of an important artist in the dome’s expression.

Charles Willson Peale was more than just an artist, he was THE portrait artist of the day and America’s first native-born artist of caliber. He would in time paint 60 portraits of George Washington alone. More about this fascinating American who would also go on to open the first museum of natural history in America and fathered numerous other famous artists can be found here on Wikipedia.

What was particularly compelling about our look at the paint history was finding that much of the dome had originally been painted a peachy-flesh tone that was over-coated with a golden glaze. It appeared the intended effect had been a golden dome – on the cheap since resources right after the Revolution were limited. In fact, although the original glaze used might not have held up for long, the golden appearance had been maintained – although in a single coat application of paint – two more times before the color scheme changed. Could it really be correct that the demure gray and white everyone was accustomed to was inaccurate?

Highlight from Charles Willson Peale sketch depicting “straw” as a key dome color. Clicking here redirects to the full image on the Maryland State Archives website.

Even more interesting was that where the color of the oval windows was not annotated we would find this detail was likely unsettled at the time as it appeared they were testing out color schemes of red versus blue in rapid succession because the earliest paint layers showed no sign of dirt deposition or weathering.

So was Peale present while color decisions were made??

Peale’s involvement in recording the paint treatments seen on the dome makes the manner in which the “straw” was achieved far more interesting. Most colors of this period were built up out of several hues and the peach tint that was used as a base for the glaze is the shade used for all female elements in art of the era (the solidity of men was expressed in grayish stone hues).

It should also be noted that Charles Willson Peale was creating his drawing at the time that Benjamin Franklin’s largest public institutional installation of a lightning rod was being placed on the Maryland Statehouse dome. Peale’s journal entries on the surrounding days highlight the thoroughness and detail of his record-keeping practices.

The State decided to stick with the Colonial Revival palette despite the more interesting historical paint evidence. Yet because we left all of the early oil paint intact and protected, it remains hidden beneath the white-painted slate and cedar shingles to inform the future, so no avenues are lost.

Author’s aside: Given that the sprinklers mounted on the exterior of the dome unpredictably engage with nearby lightning strikes which often leaves rusty water stains running down the white-painted drum of slate at the oval windows, we can only hope that a golden colored dome to camouflage these stains may one day make restoration to the earlier polychrome appearance more popular with the preservation community.

The white-painted Maryland State House dome after restoration in 2010 is now stained from rusty sprinkler pipes staining the white.
The white-painted dome of today

Never should we assume the past was sepia-toned. Rather than think of colorful renderings as an artist’s flight of fancy, the works of period artists can often help us to understand the interior and exterior palettes of the era. We hope this blend of archival and physical evidence informing our past has been a good introduction into what paint microscopy can tell us about our more colorful past.

There is a tendency on preservation projects to sample historic finishes and then obliterate them. To hope that having recorded this information will somehow inform the future is pure fantasy. Most organizations can not find a ten-year old report, let alone anything older. And most of the time they would not even think to search those earlier documents.  We must maintain the evidence in place if it is to inform the future – especially as our ability to analyze the remaining information expands with new means of analysis nearly every decade.

Rendering of original Maryland State House Dome colors as viewed from State Circle. Image by Malcolm Dax, 2010
Rendering by Malcolm Dax

The paint evidence on this project is fascinating for the curious, so it is unfortunate the polychrome history was not re-established for public interpretation. In upcoming posts we will show results from other projects that allowed full interpretation of the evidence, making seemingly “dumpy” little buildings that contractors might have felt they were “stuck with” into icons that everyone could appreciate.

Far from a simple color analysis tool, in future posts we will look further at how fluorescence microscopy can confirm or deny our suspicions, while providing great insight into the past. Microscopy can – and should – guide the treatment process.