He sits facing a nineteenth-century reproduction of a seventeenth-century refectory table. Six inches in from its nearest edge, two triangular sockets have been laser-cut into the walnut at precise angles. Into these, he has inserted a pair of nine-inch-long rods of graphite-gray ceramic, triangular in cross section, forming an acute angle. These hones fit the deep, laser-cut recesses perfectly, allowing for no movement whatever.