DUMBARTON, a royal, parliamdntary, and municipal burgh, seaport, and chief town of Dumbarton co., is situated mainly on the left bank of the Leven, near its junction with the Clyde, and 15 m. w.n.w. of Glasgow. It is rather closely built, and chiefly consists of a long semicircular street, parallel to the river. The chief branches of indus try carried on in the town of D. are ship-building, marine-engine and machine making, iron-forging, iron and brass founding, and rope-making. It has regular steam-commu nication with Glasgow, Greenock, and other Clyde ports. Pop. '71, 11,404. It unites with Kilmarnock, Renfrew, Rutherglen, and Por t Glasgow in sending one member to parliament. D. is supposed to have been the Roman station Theodosia, and the capital of the kingdom of the Britons, on the vale of the Clyde. Alexander II., in 1222, made it a royal burgh. To the e. of the alluvial plain, at the mouth of the Leven, stands the famous and picturesque castle of Dumbarton, on a steep, rugged, basaltic rock, rising to the height of 560 ft., a mile in circuit at the base, and forming nearly an island at
high water. The rock almost hides the town of D. from 'the Clyde. The fortress, composed of houses and batteries, studded over the rock, is of considerable historical interest. The rock is accessible only at one part, which is fortified by a rampart. The castle has been often besieged. A huge two-handed sword, said to be that of Wallace, is shown here. D. gave the title of earl of Dumbarton to a cadet of the house of Douglas, and commander of a regiment in the royal cause during the troubles in Scot land in the reigns of Charles :II. and James II.; the popular song,.Dumbarton's Drums beat bonny, 0, has reference to this personage, who died. in exile 'after the revolution.