BOWING OF MARBLE TABLETS AND LIMESTONE PANELS INSIDE NINETEENTH-CENTURY STRUCTURES IN NORTHERN OHIO SHOWS THAT MARBLE AND LIMESTONE CAN DEFORM INSIDE BUILDINGS UNDER VARIABLE, BUT RELATIVELY MILD CONDITIONS

We have found that every one of the 14 large (2.16-m-high) fine-grained white marble tablets in the interior of the 1876 Memorial Chapel in Akron's Glendale Cemetery is bowed. Maximum bowing (measured diagonally) is 35 mm (15 mm/m). The marble in the Chapel is similar to that used for the 2.5-cm-thick memorial tablets in the 1894 Cuyahoga County Soldiers and Sailors Monument in Cleveland, which have previously been shown to be bowed, but the tablets in the Akron Chapel are about 4-cm thick, and the Chapel, unlike the Monument, has not been heated in many years.

We also have measured bowing of fine-grained white marble inside a 19th-century mausoleum in Cleveland's Lake View Cemetery and in an interior doorway in a 1903 building in Cleveland. In addition, we note bowing of large panels of “Numidian marble,” a limestone breccia, inside the 1890 Garfield Monument in Cleveland. It is likely that heat cycles played the most important role in this bowing, but the exact relationship is not clear. Conditions to which interior marble is exposed are generally moderated by their being inside structures. Exterior marble cladding is subject to greater environmental stress, including direct solar radiation.

Since every one of the large panels we have measured in the Akron Chapel and the Cuyahoga County Monument are bowed to some extent, and all three of the major nineteenth-century monuments we have examined have bowing marble or limestone, we can confidently predict that there are numerous unnoticed cases of bowed interior marble. Published comments referring to the bending of marble extend back to at least the 1820s, and explicit warnings about the phenomena can be found in Booth's 1865 Marble-Worker's Manual. Severely bowed slabs may be replaced, but that destroys historic integrity, especially in the case of tablets that were carved or etched over 100 years ago. Nineteenth-century, and more recent, references suggest that marble slabs can be rebent to maintain a building's historical integrity.