TROON, a promontory, a harbour, a thriving sea-port, and a quoad sacra parish, at the west end of the parish of Dundonald, Ayrshire. The town, situated on the promontory, is 6 miles north of Ayr, 6 south of Irvine, 9 south-west of Kilmarnock, 31 south-west by south of Glasgow, and 75 west-south-west of Edinburgh. The promontory is a belt of rock, extending 1¼ mile into the sea, and so curved as to form a large segment of a circle, with the concave side facing the north. Its mean breadth is only about 2 furlongs. In its natural state it was covered with rich pasture toward the land, but became naked rock toward the extreme narrowing point. A continuation of the promontory extends a short distance beneath the sea, so as to be concealed even at low water. The embayed marine space embraced by the bold curvature is by far the best natural harbour in Ayrshire; it affords safe anchorage-ground from every quarter except the north-west; and, at half-a-cable’s length from the rock, it has, at half-flood, a depth of 3 fathoms. The merchants of Glasgow, aware of its advantages, made a vain effort, about the year 1700. to purchase the circumjacent property for the erection of a sea-port; and, in consequence of the repulse they met, were obliged to select the very inferior site of Port-Glasgow as the station next in eligibility. After the effluxion of a century, the Duke of Portland, the proprietor, commenced a series of vigorous operations to render the place fully available for commerce. About the year 1817, he constructed a new pier 800 feet long, nearly at right angles with the rock, where the depth is 19 feet at low water, and he afterward constructed a fine wet dock with floodgates, a dry dock for repairing vessels, a light-house, and large store-houses. Due encouragements were offered to make the place a resort of trade and a seat of population; and they were rapidly followed by success. A railway hither from KILMARNOCK [which see] was the first public work of its class in Scotland, and brings down vast quantities of coals for shipment to Ireland, Galloway, and other destinations. A new act of parliament was obtained in 1837 to alter and amend this railway, and to raise sufficient funds for the object. A communication is maintained likewise with the Glasgow and Ayr railway, the main line of which passes in the vicinity. During the year which ended on 31st August, 1840, no fewer than 165,850 tons of coals were shipped. In 1837, 1,060 vessels of aggregately 79,291 tons, took part in the port’s trade; and, in 1840, upwards of 30 vessels belonged exclusively to the place. The town is built along a large part of the promontory, and forms a conspicuous and fine feature in the broad and brilliant landscape of Ayrshire and the frith, as seen from numerous vantage-grounds, 8 or 12 miles to the south or north. Many of the inhabitants are employed in a large ship-building yard, a rope and sail manufactory, and some other works; and not a few of them draw an entire or partial maintenance from letting lodgings to families of sea-bathers. The town has a branch-office of the Ayr bank. The quoad sacra parish consists of the town, and a small district in its vicinity. The church was erected, in 1836, at a cost of £1,100. Sittings 900. A chapel belonging to a United Secession congregation which was formed in 1822, and for some years dissolved, and formed anew in 1839. was built, in 1822, at a cost of £320. Sittings 289. In 1836, the population of the town was 1,088, and of the town and, district extending 2 miles from it 1,600.