Stone support vaults in cellar of 1765 George Douglass House

Photo #21 shows a stone arch in the cellar aligned diagonally to support the corner fireplace in the room above that served as the original "Amity Store" starting in the late 1760s [photo #15, 2/23/22, shows the fireplace arch as recently restored by setting replacement "voussoirs" (arch-stones) at the proper radius on a "centering frame", in place until the arch-mortar "sets up"; similar voussoir alignment is seen in photo 736, which is the arched vault in the cellar supporting the restored store-room fireplace shown in photo 15. Drawing GDH FP Vaults is a schematic drawing of the large arched vault supporting the kitchen fireplace, and the smaller vault to the left that serves as a structural abutment to the vault that supports massive loads from the fireplace and chimney masonry above. The smaller vault restrains the lateral thrusts imposed by the large vault [see Arch Forces drawing, 4/13/15, attached showing force vectors acting laterally as well as vertically downward, in "compression"]. See also photo 5573, 11/11/13, showing these two vaults mechanically integrated by bearing on a shared triangular "impost" stone atop the pier between them. The force vector bearing on the impost from the fireplace vault is stabilized [vernacular: "neutralized"] by the smaller abutting arched vault compressed only by the smaller load consisting of the masonry and flooring bearing on it from the doorway passage above. No evidence has been found to indicate that any oven, cauldron or other structural mass within the doorway passage to the left of the kitchen fireplace that would have been borne by the smaller vault. The date of the doorway is not known by architectural evidence Larry Ward, March, 2022, June 2023