pound of the salt to each gallon of water, according to Margary's patent, has been found very efficacious in the case of timber not liable to the solvent action of water; but of all processes the most satisfactory is Bethell's. In this the wood is injected with heavy tar-oil in cylinders 6 feet in diameter and 20 to 50 feet in length, at a temperature of 120° Fahr., and under a pressure of 150 lb to the square inch, so that ordinary fir timber absorbs on the average 8 to 10 lb of the liquid per cubic foot. Timber thus prepared has been found not only durable, but also exempt from the attacks of insects and other pests.
J. Papworth, An Essay on the cause of the Dry Rot in Buildings, 1806; Bowden, A Treatise on the Dry Rot, 1815; Wade, A Treatise on the Dry Rot in Timber, 1815; Chapman, On the Prevention of Timber from Premature Decay, 1817; M'Williams, Essay on the Origin and Operation of the Dry Rot, 1818; Burnell in Journal of the Society of Arts, June 1, 1860, vol. viii.
DU BARRY GOMARD DE VAUBERNIER, Marie Jeanne, Countess (1746-1793), mistress of Louis XV., was the daughter of Vaubernier, a clerk of the customs at Vaucouleurs, and was born there on the 19th August 1746. She received little or no education, and, coming to Paris while yet very young, she entered the house of a "marchande de modes." She soon fell a victim to the temptations which there beset her, and lived as a courtesan under the name of Mdlle. Lange. Her great and peculiar personal charms led Jean Count Du Barry to form the design of receiving her into his house, in order to make it more attractive to the dupes from whom by gambling he Avon money to furnish him with the means of dissipation. Her success surpassing his expectations, his hopes took a higher flight, and he presented her to Lebel, valet de chambre of Louis XV., with the intention that she should become the mistress of the king. In this she succeeded; but as the favour shown by Louis to a courtesan roused murmurs in the court and remonstrances from his ministers and the members of the royal family, Louis, who was too infatuated to remove her, met their wishes half-way by securing for her a nominal husband. Count Jean Du Barry was married himself, but his brother William offered himself for the ceremony, and after its performance the Countess Du Barry was presented at court on the 22d April 17G9. Her influence over the monarch was absolute until his death, and courtiers and ministers were in favour or disgrace with him in exact accordance with her wishes. The Due de Choiseul, who refused to acknowledge her, was disgraced in 1771; and the Due d Aiguillon, who had the reputation of being her lover, took his place, and in concert with her governed the monarch. The favour of Louis for the Countess Du Barry continued to estrange him from his children and from the most of the royal family, and this isolation induced him to build for her the magnificent mansion of Lucieunes. At his death in 1774 an order of his successor banished her to L Abbaye-du-Pont-aux-Dames, near Meaux, but the queen interceding for her, the king in the following year gave her permission to reside at Luciennes with a pension. Having gone to England in 1792 to endeavour to raise money on her jewels, she was on her return accused before the Revolutionary tribunal of having dissipated the treasures of the state, conspired against the republic, and worn, in London, " mourning for the tyrant." She was condemned to death December 7, 1793, and beheaded the same evening.
DUBLIN, a maritime county of Ireland, situated in the province of Leinster, and containing the Irish metropolis. It is bounded on the N. by the county Meath, E. by the Irish Sea, S. by Wicklow, and W. by Kildare and Meath. With the exception of Louth and Carlow, Dublin is the smallest county in Ireland. Its greatest length is 32 miles, its greatest breadth 18; and the area is 354 square miles, or 226,895 acres.
Geology.—The greater part of the county rests on the eastern extremity of the great bed of flotz limestone that extends over the middle of the island, widening as it spreads westward. It rises in its southern part into a range of mountains, which forms the verge of an elevated district, extending thence for more than thirty miles to the south through the county of Wicklow. Through this tract a large body of granite passes in a south-western direction, commencing at Blackrock and passing by Dundrum and Rathfarnham, and forming the loftiest summit in the county, bounded on its eastern and western sides by incumbent rocks of great variety of structure arid relations; micaceous schist exists at Killiney and Rathfarnham, and argillaceous schist, on both sides of the granite and quartz rock, in the eastern side alone, forming the promontory of Bray Head, and reappearing in the more northern part of the county, where it forms the picturesque peninsula of Howth, and rises to the height of 567 feet above the level of the sea. The country near Bray presents, within a small space, an instructive series of rocks; and at Killiney schistose beds are to be seen", of considerable extent, reposing on granite. Near Booterstown, a mass of compact limestone is visible within a few fathoms of the granite. Calp, or "black quarry stone," a variety of limestone, is the prevailing rock in the immediate vicinity of Dublin, and is much used for building; and the granite of Dalkey and the neighbourhood is also much used for architectural purposes in the city and environs; quantities of it are exported to Eng land. Petrifactions abound in many parts of the limestone country. In the peninsula of Howth gray ore of manganese, brown ironstone, and brown iron-ore occur in abundance. Surface.—The northern portion of the county is flat, and the soil good, particularly on the borders of Meath; but on the southern side the land rises into elevations of consider able height. The mountains are chiefly covered with heath, except where a subsidence in the ground affords a nucleus for the formation of bog, with which about 2000 acres are covered. There are also a few small tracts of bog in the northern part of the county. The mountain district is well adapted for timber, to the growth of which some attention has lately been paid. Coast.—The northern coast of the county from Balbriggan to Howth has generally a sandy shore, and affords omy the small harbours of Balbriggan and Skerries. In the promontory of Howth, the coast suddenly assumes a bolder aspect; and between the town of Howth and the picturesque rocky islet of Ireland's Eye an artificial harbour has been constructed, at an expense of above one-third of a million sterling, which is useful only to vessels of small burthen, and those engaged in the fisheries. Soon after the harbour was finished it was discovered that a shifting sand bank was likely to render the refuge quite useless; and the slow but certain filling up of the harbour is made apparent at low tide. Kingstown harbour, on the south side of Dublin Bay, is by far the best in the county. It was commenced in 1816, and was not quite finished until 1859, at a total expenditure of 825,000. A quay runs out into the harbour to a distance of 500 feet, at which vessels drawing 24 feet of water may unload at any state of the tide. The petty harbours of Bullock and Coolamore are on this coast, the former being quite dry save at high tide, and the mouth of the latter being much higher than the bed. Balbriggan is little better, and that at Skerries is hardly to be mentioned. Opposite Coolamore harbour lies Dalkey Island, and the sound between the island and the shore is held to be dangerous in certain conditions of weather. The island is 22 acres in extent, and stands about midway between Kingstown harbour and the beautiful bay of Killiney. North of Howth lies Lambay Island,
