SARPSBORG, a seaport and manufacturing town of Norway, in Smaalenene amt (county), 68 m. S.S.E. of Christiania on the Gothenburg railway. Pop. (1900) 6888. It is the junction for an alternative line to Christiania following the Glommen valley. It sprang into importance through the utilization of the falls in the river Glommen for driving saw-mills and generating electric power. The Sarpsfos, south-east of the town, is a majestic fall, descending 74 ft. with a width of 120 ft. There are wood-pulp factories (one worked by an English company employing over 1000 hands), factories for calcium carbide (used for manufacturing acetylene gas), paper and aluminium; and spinning and weaving mills. There are two large electric supply stations, and power and light are furnished from this point to Frederikstad, 9 m. S.W. The port is at Sannesund, 1 m. S.; its quays can be reached by vessels drawing 20 ft. The town was originally founded in the 11th century, and destroyed by the Swedes in 1567. The existing town dates from 1839.