On the outskirts of Doylestown, in the heart of Bucks County, Pennsylvania, stand three medieval-looking buildings locally referred to as the "Mercer Mile." Within little more than a mile of each other, they were built by a highly unusual man whose innovative interest in concrete was half a century ahead of his time. Dr. Henry Chapman Mercer was an American "original" whose creative genius is more clearly seen as time goes on.
Dr. Mercer's 27-room concrete mansion was designed as a showcase for his pottery, tiles and assorted other treasures. It contains cabinets, bookcases, tables and other pieces of furniture made of concrete. This remarkable home actually enveloped a small 18th century farmhouse, literally encasing it in concrete. The only exposed wood is the floor of the old house (now the kitchen) and the dumbwaiter. Dr. Mercer's notes tell us: "Columns rise from the cellar to housetop through several rooms without symmetrical arrangement. Their forms were made by boards set vertically and held together in circles with rope and wire, or in squares with battens. Each was reinforced with three vertical pipes and wire circles twisted by hand and dropped down the forms about 2 feet apart."
The construction of the multivaulted and irregularly shaped ceilings is of particular interest. A platform was erected under the proposed ceiling level; earth was piled on it and patted by hand into the desired shape; sand was placed over the soil, and the concrete was then poured. Roof, dormers and skylights are all framed in concrete. Amazingly, even the gutters are cast as an integral part of the roof. Mercer's notes indicate, "A batch consisted of one bag of cement equal to one and two-thirds buckets, three buckets of sand, and six buckets of stone. The waterproof roof, about 5 inches thick, of concrete, lacks patent waterproofing compounds, and all of the galleries and floors rest on vaults rather than beams."