External stucco finishes, applied by plastering methods, were common in many of the earliest and most primitive of buildings. Their history starts with "wattle and daub," in which clay plastering was the finishing material. Lime was probably first used as the binding medium by the Romans, both for internal and external finishes, and the type of mix introduced by them was used for external work with little change or improvement until the latter part of the eighteenth century. The types of finishing treatment for external renderings which are available to the user include the following: pebble-dash or dry-dash- a rough finish in which small pebbles or crushed stone of suitable size are thrown on to a freshly applied final coat of mortar and left exposed. The pebbles or stones are sometimes lightly pressed or tapped into the mortar after throwing. Roughcast, wet-dash, or harling- a finish in which the final coat, containing a proportion of fairly coarse aggregate, is thrown on as a wet mix and is left in the rough condition. The coarseness of the texture depends mainly upon the type and size of the coarse aggregate. Scraped finishes- finishes in which the final coat of mortar after leveling and allowing to stiffen, usually for several hours, is scraped with a steel straightedge, a board studded with nails, a wood float covered with expanded metal or any other form of tool convenient for the purpose, to give a roughened surface. Textured finishes- a variety of finishes having textured or patterned surfaces produced by treatment of the freshly applied final coat with various tools. Examples are: ribbed stucco, horizontally or vertically; torn stucco, stippled stucco, fan texture; and English Cottage Texture. Smooth (floated) finishes in which the surface is made level and relatively smooth with a float. A wood float is normally used for this, as a steel float gives a surface much more liable to craze. Machine-applied finishes- a variety of finishes in which the final coat is applied by machines which spatter or throw the material on to the wall, the roughness of the finished surface varying with the material used and the type of machine. Some machines are hand operated, the material being projected on to the wall by sprung tines or "flickers" on a horizontal rotating spindle partly immersed in the mix. Others are mechanically operated, using similar methods of projection, while another group use pneumatic projection from a gun.