See La Valli£re.
Dean Forest, a royal forest of Gloucester, England, W. of the Severn, and 10 m. S. W. of Gloucester; area, about 22,000 acres, one half of which is now set aside for navy timber; pop. about 11,000. Anciently nearly all that part of the county lying W. of the Severn was included within its limits. It embraces a number of plantations of oak, beech, and other trees, and orchards famous for the production of styre-apple cider. It abounds in coal and iron, and several railways have been constructed from the mines to the Severn, Wye, etc. Dean Forest is divided into six districts called walks, and is the property of the crown. The inhabitants, who are mostly employed in mining, pay no county rates.
Decapods, the order of ten-footed crustaceans, having normally nine cephalic segments and five foot segments, each of the latter bearing a pair of so-called feet. They embrace the highest crustaceans, like the crabs, lobster, and squill. The lower forms extend back in time, as far as is positively known, to the beginning of the carboniferous period.
Decapolis (Gr. ten, and city), a district of eastern Palestine, which contained the following ten cities: Damascus, Philadelphia, Raphana, Scythopolis, Gadara, Hippos, Dion, Pella, Galasa or Gerasa, and Canatha. The cities were probably rebuilt, partially colonized, and given political privileges after the conquest of Syria by the Romans, 64 B. C, and at some time were confederated. The word is not used to designate the country after the 1st century.
Decazeville, a town of France, in the department of Aveyron, 20 m. N. N. E. of Ville-franche; pop. in 1866, 7,106. It has coal and iron mines, and its blast furnaces and rolling mills are among the best in the country. It was founded by Duke Elie Decazes in 1825.
December, the 12th and last month of the year, consisting of 31 days. With the Romans it was the 10th month, whence its name (from decern, ten); and after the change in the calendar by which the beginning of the year was transferred from March to January, it still retained its old name. In the Athenian calendar the last half of Poseidion and the first half of Gamelion correspond to December. In the French revolutionary calendar December is represented by the last two thirds of Fri-maire and the first third of Nivose. As the winter solstice falls in the month of December, the average length of the days is less and of the nights greater than in any other month of the year.
Decimal (Lat. decern, ten), a number in a geometrical progression whose ratio is 10; that is, in a progression by tens, hundreds, or by tenths, hundredths, and so on. Decimal notation is the system of uniting numbers in which the value of a figure increases tenfold with every remove to the left, and decreases a tenth by every remove to the right, from a point between the units and tenths designated by a dot. Numeration by decimals was doubtless suggested by the fingers of the hand, and therefore may be called natural; but other systems, as the binary and duodecimal, possess certain advantages over it. So long, however, as arithmetic uses a decimal ratio, it will be most convenient, for all purposes of calculation, to have money, weights, and measures divided decimally, as the first is in the United States, and all are to a great extent in France.