COFFER DAM

an enclosure round the ns,|spot where the foundation of a pier or a | wall has to be — under water, for the tic | purpose of shutting out the water, so that It|the work may be done in the dry. It ch | consists of parallel rows of closely arranged ed | piles, having the space between the rows he | filled with clay, for| COGNAC, 2 smzll town in France, about ts,| 70 miles north of Bordeaux. The chief 1g- | industry is the distillation and export of brandy, sold under the name of Cognac; by | population about 20,000. ng | COHESION, « name applied to the force is, | with which the molselnans = Sedy cote m.| separation. Thus the particles of which id |a piece of wood is made up are more he | casily forced asunder than those of a pleco it | of iron, those of chalk more easily than rs | wood, and soon. Liquids have very littlo ag | cohesion, and gases none at all, the parry | ticles repelling one another, Cohesion is weakened by heat, b [s. 103]