patents were obtained for "compositions" in 1803 (Thomas Fulchner), 1815 (Christopher Dihl) and 1817 (Peter Hamelin). These oil mastics, as the ones before them, also proved to be short-lived. Moulded or cast masonry substitutes, such as cast stone and poured concrete, became popular in place of quarried stone during the 19th century. However, this was not the first time "artificial stone" had been widely used. Coade Stone, a brand name for a cast stone made from fired clay, had been developed and manufactured in England from 1769 to 1843 and was used for decorative architectural elements. Following the closure of the factory in South London, Coade stone stopped being produced, and the formula was lost. By the mid 19th century manufacturing centres were preparing cast stones based on cement for use in buildings. These were made primarily with a cement mix often incorporating fine and coarse aggregates for texture, pigments or dyes to imitate colouring and veining of natural stones, as well as other additives. Also in the 19th century, various mixtures of modified gypsum plasters, such as Keene's cement, appeared. These materials were developed for use as internal wall plasters, increasing the usefulness of simple plaster of Paris as they set more slowly and were thus easier to use. Tools and materials Tools and materials include trowels, floats, hammers, screeds, hawk, scratching tools, utility knives, laths, lath nails, lime, sand, hair, plaster of Paris, a variety of cements, and various ingredients to form color washes. While most tools have remained unchanged over the centuries, developments in modern materials have led to some changes. Trowels, originally constructed from steel, are now available in a polycarbonate material that allows the application of certain new, acrylic-based materials without staining the finish. Floats, traditionally made of timber (ideally straight-grained, knot-free, yellow pine), are often finished with a layer of sponge or expanded polystyrene. Laths Traditionally, plaster was laid onto laths, rather than plasterboard as is more commonplace nowadays. Wooden laths are narrow strips of straight-grained wood depending on availability of species in lengths of from two to four or five feet to suit the distances at which the timbers of a floor or partition are set. Laths are about an inch wide, and are made in three thicknesses; single ( thick), lath and a half ( thick), and double ( thick). The thicker laths should be used in ceilings, to stand the extra