These ornaments, such as centre pieces for ceilings, flowers drooping from cornices, bosses or groups on walls, &c. are first modelled in clay, and are afterwards cast in plaster of Paris, placed in moulds made of wax or plaster. In this trade, as in that of the picture frame maker, ornaments are frequently made of _papier maché_, or the pulp of paper (literally _smashed paper_), which is a very light, hard, and durable substance for the purpose. The moulds for cornices are made of sheet copper, and are fixed in a wooden frame. [Illustration: Gauging Trowel. Hammer. Salve. Plasterer’s Hawk. Check Line and Reel.] The various tools used by the Plasterer are shown in the engravings, and the manner in which some of them are used may be seen by the large cut at the commencement of this description of the Plasterer’s trade. The peculiar _hammer_, with one edge like an axe, is used for breaking down old plaster, and clearing away the mortar from walls and ceilings previous to plastering them afresh; the _hawk_ is a flat board with a handle in the centre, used for holding the plaster or cement, which is being laid on with the trowel. The _gauging trowel_ is the long narrow trowel, used for taking up the fine stuff for cornices and mouldings; these trowels are of various lengths, from three to seven inches. The _salve_ is a sort of small spade, on which the plasterer’s boy lifts the mortar or cement, and places it on the _hawk_, which the workman holds in his hand; as the _salve_ has a long handle, the plaster can be conveyed to the hawk even when the man is at work on a ladder. The square is similar to that used by the bricklayer, and shows that the corners of the work are straight and even; the _compasses_ are used for measuring distances; the _check line_ for marking out the spaces of the work to be done, and the _joint rules_ for measuring the parts where different portions of the work come together, either at the corners, or in making the mouldings. The _set square_ is also used, for showing that the surface or the line of the work is straight and even. [Illustration: Joint Rule. Joint Rule. Compasses. Set Square.] When the Plasterer has to cover a ceiling or a partition, he commences by lathing. This is nailing laths over the whole space which is to receive the plaster. Laths are long narrow strips of either oak or fir wood, of various thicknesses; the thicker being used for ceilings, where they have to bear a greater strain than in upright walls.