Stone Arch Bridges Beginning in the 1830's, a few arched granite highway bridges were built in southern New Hampshire under the supervision of engineers from major manufacturing centers. By the 1850's, rural stonemasons had mastered the art of building such bridges without mortar. Hiram Monroe (1799-1871), active in town affairs, persuaded Hillsborough to build a dozen. Five survive, and a sixth is covered by Franklin Pierce Lake. Among the local builders were Reuben E. Loveren (1817-1883), and brothers Calvin A. Gould (1826-1877) and James H. Gould (1828-1890). All three worked on this, the double-arched Sawyer Bridge, in 1866.