George Duglass House Cellar

The proposed replacement of the kitchen door and frame in the gable recess next to the large cooking fireplace required the Trust to investigate the vaulted support structure [photo #5775, 11/18/13] in the corner of the cellar. Located adjacent to the fireplace support vault and directly below the short doorway passage adjacent to the kitchen fireplace, this narrow vault would intuitively be expected to have been constructed as a bearing structure for a load-mass, such as a bake-oven, imposed on it from above. Inspection of the material and form under the floorboards might disclose whether any bed mortar or leveling course remains as a bearing plane for a masonry feature in the kitchen above. The wide-span vault, which shares an abutment pier with the corner-vault, is a prime and enduring example of a masonry structure in stable equilibrium under the massive compressive load of the fireplace and chimney stack imposed on it. No scale-equivalent load is borne by the smaller vault and there is no evidence that it ever did so. The space above it has been a passage to the gable doorway from an early period, and perhaps is an original detail recognizing the utility of a direct route through the gable to an out-kitchen, store-yard, or other work space associated with the store and food processing enterprise engaged in by the Douglasses by the 1760s. It has been comjectured that the smaller vault was constructed before Georg Douglass decided to devote the corner recess to a doorway passage. It is hard to believe that the doorway was an afterthought brought to mind only after the masons had spent considerable time and material constructing a classic arch-form vault. Rather than speculating what purpose was intended for this vault, it seems more appropriate to recognize what function is actually served by it. As currently configured, the small vault is an ideal buttress for the large vault supporting the kitchen fireplace. The two vaults share the narrow pier as a common "jamb" and provide perfect lateral support for each other. There seems to be no evidence in the eastern jamb of the fireplace that an access-aperture to a bake oven or other kitchen cooking structure. The location of the trammel "squinch" is also an indication that no bake oven abutted the kitchen fireplace. In the absence of such evidence, the small vault terminating at its eastern springing in the foundation wall , which is redundantly buttressed by the earthen subsoil against the foundation wall, might be viewed as an cost-effective means of providing a mechanically perfect buttress against the lateral thrust of the larger arch supporting the kitchen fireplace. The arched abutment serving this function provides a margin of structural redundancy and is significantly more efficient than a massively thick pier installed for this purpose{1}, and requires little or no additional materials. In modern terms, this diminutive arch is the "elegant" vernacular solution to the classic problem of arch stability. There are several other support vaults in the Douglass cellar. {1} The support vault under the entry to the Shelley barn from the wagon ramp has a_____ foot wide abutment pier.