Staff
a kind of artificial stone used for covering and ornamenting buildings.
It is made chiefly of powdered gypsum or plaster of Paris, with a little cement, glycerin, and dextrine, mixed with water until it is about as thick as molasses, when it may be cast in molds into any shape. To strengthen it coarse cloth or bagging, or fibers of hemp or jute, are put into the molds before casting. It becomes hard enough in about a half hour to be removed and fastened on the building in construction. Staff may easily be bent, sawed, bored, or nailed.
Its natural color is murky white, but it may be made of any tiat to resemble any kind of stone.
Staff was invented in France about 1876 and was used in the construction and ornamentation of the buildings of the Paris Expositions of 1878 and of 1890. It was also largely used in the construction of the buildings of the Columbian Exhibition at Chicago in 1893, at the Omaha and Buffalo Expositions in 1898 and 1900, and at later expositions and on temporary buildings of other kinds. show themselves to be of three kindsconglomerated tufa, forming the basement; columnar basalt, arranged in colonnades, which form the façades and the walls of the chief caves; and amorphous basalt, overlying the columnar basalt, but pierced here and there by the ends of columns and by angular blocks. The most remarkable feature of the island is Fingal's, or the Great Cave, the entrance to which is formed by columnar ranges on each side, supporting a lofty arch, The entrance is 42 feet wide, and 66 feet high, and the length of the cave is 227 feet. The floor of this marvelous chamber is the sea, which throws up flashing and many-colored lights against the pendent columns, whitened with calcareous stalagmite, that form the roof, and against the pillared walls of the cave.