DISE, or DYKE, a word variously used to represent a ditch or trench, and also an embankment, rampart, or wall. It is specially applied to an embankment raised to oppose the incursions of the sea or of a river, the dikes of Holland being notable examples of works of this kind. Laws concerning dikes are found in the old Saxon and Swabian codes. The ancient ordinances concerning dikes rest for the most part on the unwritten law or autonomy. The most important and complete code of regulations is the ordi nance of the Duchy of Bremen of 1743. Of later ordinances the Prussian law of Jan. 28, 1848, and the so-called "Deich ordnung" for the Duchy of Oldenburg, June 8, 1855, are notable. Owing to the possibility of great loss of property and of life, the punishment of all neglect or for malicious mischief to dikes is ex tremely severe. The dikes which protect the Netherlands and the German coasts of the North Sea go back to the old Roman times. Apparently even before the Romans appeared the Batavians at the mouth of the Rhine protected them selves by dikes. Drusus after the con quest of Holland, 10 B. C., built an elab orate system of artificial canals and dikes. Pliny the Elder gives interesting descriptions of the artificial hills, which were erected at places of refuge during the floods. In the 10th and 11th cen turies the archbishops in Bremen sum moned the native inhabitants to the building of dikes to protect the marshes of Bremen.
Among the provinces in north and south Holland which have been protected by dikes may be mentioned the province of Hanover, 618 miles, protecting 770,000 acres of marsh land. On the left bank of the Oder river there is a dike which protects more than 170,000 acres of land.
The dike at the delta of the Vistula pro teeth 134,000 acres of land. On the lower Rhine, between the Wesel and Holland are 115,000 acres protected by dikes. Along the Loire river are 280 miles pro tecting 230,000 acres. Along the Po there are 310 miles protecting 850,000 acres. In England there are 1,750,000 acres protected by dikes.
In the United States the term dike is almost wholly restricted to the structures of more or less permanence built in va rious ways in the bed of a stream to regulate its flow, narrow the low water cross section, concentrate the current, in crease its local scouring effect and there by deepen the river channel. The earthen embankments designed to restrain the flood waters are called levees. The most notable examples are found along the Mississippi river where it winds its way through the alluvial plain which it has built up below the mouth of the Ohio river. These levees are placed some lit tle distance back from the river, and according to the local conditions vary in height from two or three feet to over 20 feet. In 1850 the General Government granted to some of the States certain public swamp lands, the revenue from which was to be used in levee building. With the exception of this aid from the United States, all levees up to 1882 were built by funds raised by local taxation of the lands to be benefited and adminis tered by levee boards organized under State laws. Since 1882 the General Gov ernment has pursued the policy of aid ing the local levee boards in raising and strengthening their levees.