The large scale expansion of the brass industry dates from the late 17th century. Improvements in the supply of zinc combined with an increasing understanding of the chemical structure of the alloy drove this expansion. Equally, brassfounders began increasingly to use moulds of sand instead of clay thus making cheaper castings possible and from this time the range of cast, brass goods increased dramatically. By the 19th century, brass had become extremely versatile and inexpensive and the applications were almost endless.