was to introduce three cylindrical holes or tunnels in the masonry at those parts of the bridge. Among the more important of the later works of Edwards were the large bridge over the river Usk, at the town of Usk, in Monmouthshire; one, of three arches, over the river Tawe, near Swansea; another, of one arch of 95 feet span, over the same river near Morriston. In 1750, he became an ordained preacher among the independents. Shortly after, he was chosen minister of congregation to which he belonged, and he continued to hold the office for about forty years, until his death. Famous bridges Edwards' most famous creation was the Old Bridge at Pontypridd, built between 1746 and 1756. The contract included a "guarantee" clause, and Edwards actually constructed four successive bridges at the same site, with only the last surviving the torrential waters of the river Taff. The first bridge had three arches which were swept away by flood water after two and a half years. The second, a bold single arch design, was also swept away before completion. The third attempt failed due to the weight of the haunches causing the centre to fail. At 140 ft, the fourth and final version was the largest single-span bridge in the world when it was completed, exceeding the previous largest, the Rialto Bridge in Venice, by some 42 feet. Edwards' master-stroke was to lighten the weight of the haunches by leaving "holes" in the structure. The resulting construction still stands today, although another bridge next to it carries modern traffic and Edwards bridge is only now used by pedestrians. The bridge opened in 1755 and celebrated its 250th anniversary in 2005. Edwards also went on to build or design bridges in Aberafan, Betws, Cilycwm, Glasbury, Pontardawe and Usk, and was also responsible for the layout of Morriston, the planned industrial village near Swansea developed by the Swansea Valley industrialist Sir John Morris. Works by Edwards (and sons) Source c. 1740 Forge at Cardiff 1746–1756 Old Bridge, Pontypridd. 1 arch, 140 ft span. 1746–1752 Usk Bridge, Usk. 5 arches. Widened 1856. ? Beaufort Bridge. 3 arches. Demolished 1868. ? Pontardawe Bridge. 1 arch, 80 ft span. ? Betws Bridge. 1 arch, 45 ft span. 1760s Workshops at Morriston c. 1768 Aberafan Bridge, 1 arch, 70 ft span. Demolished 1842. c. 1768 Morriston new town. 1773 Dolauhirion Bridge. 1 arch, 84 ft