Doombook, a code of laws compiled by King Alfred from the West-Saxon collection of his ancestor Ina, and comprising small portions of
the Mercian laws of Offa, and of the Kentish collection of Ethelbert. The code begins with the words: "The Lord spake these words to Moses, and thus said: I am the Lord thy God".—Cf. B. Thorpe, Ancient Laws and Institutes of England.
Doon, a river in Ayrshire, Scotland, which issues from the long, narrow Loch Doon, and falls into the Firth of Clyde; length, 27 miles.
Doppler's Principle, the principle by which the motions of heavenly bodies in the line of sight can be determined spectroscopically. When the distance between a body and the observer is being diminished, the number of waves of light of any definite colour received from it per second is increased, just as a swimmer meets more waves in the same time if he swims to meet them. Each colour of light is, therefore, slightly shifted towards the violet end of the spectrum. Thus any radiation or absorption lines seen are shifted towards the violet. If the body's distance is increasing, they are shifted towards the red. By investigation of such displacements, the motions of stars, nebulæ, &c., in the line of sight can be measured, the dimensions of the orbits of double-stars gauged, the motions of gases in the solar atmosphere determined, and the rotational velocity of the sun's surface found for latitudes where sun-spots are rarely or never visible. The speed and direction of the sun's motion through space, viz. 12 miles per second towards a point in the constellation Hercules, has also been determined by this means.
Dor, or Dorr, the black-beetle, Geotrūpes stercorarius, one of the most common British beetles, of a stout form, less than 1 inch long, black with metallic reflections, not to be confounded with the cockroach, commonly but erroneously called black-beetle. It may often be heard droning through the air towards the close of the summer twilight.
Dora, the name of two rivers in Northern Italy, both tributaries of the Po. The Dora Baltea rises on the southern slopes of the Mont Blanc group, and falls, after a course of about 100 miles, into the Po below Chivasso; the Dora Riparia, about 75 miles long, rises in the Cottian Alps, and joins the Po below Turin.
Do´ran, John, English writer, born 1807, died 1878. He began writing when a mere youth, and produced a great number of books, among them being Lives of the Queens of England of the House of Hanover, Monarchs retired from Business, History of Court Fools, The Book of the Princes of Wales, Their Majesties' Servants (a history of the English stage from Betterton to Kean), Saints and Sinners, A Lady of the Last Century (Mrs. Montague), London in Jacobite Times, and Memories of Our Great Towns. In and about Drury Lane was published after his death. He was editor of Notes and Queries at the time of his death.
Dorcas Society (from Dorcas mentioned in Acts, ix, 36-42), an association generally composed of ladies for supplying clothes to the poor. Frequently the members of the society meet at stated times and work in common. Partial payment is generally required from all recipients except the very poor. Most of these societies are connected with churches of one denomination or another.
Dor´chester, a municipal borough of England, chief town of Dorsetshire, 118 miles S.W. of London. There are large cavalry and infantry barracks a little to the west of the town. The trade consists chiefly in agricultural produce. Dorchester was an important Roman station (Durnovaria), and many interesting Roman remains, such as the 'Maumbury Rings' (a Roman amphitheatre), are still to be found in the vicinity. It was a parliamentary borough till 1885, when it was merged in the county. Pop. 9842.
Dordogne (dor-dony), a department of France, which includes the greater part of the ancient province of Périgord, and small portions of Limousin, Angoumois, and Saintonge. Area, 3544 sq. miles, of which about a third is fit for the plough. The chief minerals are iron, which is abundant, slate, limestone, marble, and other stone. Mining, iron manufacture, &c., are carried on to a considerable extent, and there are a number of vineyards. The climate is mild but somewhat changeable. Pop. 396,702.—The river Dordogne, principal river of the department, rises on the flanks of the Puy-de-Sancy, flows W.S.W., and, after a course of 290 miles, unites with the Garonne in forming the Gironde.