flaying nailed the laths in their appropriate order, the next business is to cover them with the plaster, in doing which, the most simple and common operation is that of, 2. Laying : this consists in spreading a single coat of lime and hair all over a ceiling, or partition ; carefully observing to keep it even and smooth in every direction. This is the cheapest kind of plastering.
3. is performed in the same manner as the foregoing, but it is only a preliminary to a more perfect kind of work. After the plaster is laid on, it is crossed all over with the end of a lath, to give it a key, or tie, for the coat that is to be laid upon it.
4. Lathing, laying, and set, is when the work, after being lathed, is covered with one coat of lime and hair, and, when that is sufficiently dry, a thin and smooth coat is spread over it, consisting of lime only, or, as the workmen call it, putty or set. This coat is spread with the smoothing-trowel, which the workman uses with his right hand, while in his left hand he is thrnished with a large flat brush of hog's bristles. As he lays on the putty, or set, with the trowel, he draws the brush, dipped in water, backwards and forwards over it, and thus produces a surface tolerably even for cheap work.
5. Lathing, floating, and set, differs from the foregoing, in having the first coat pricked up to receive the set, which is here called the floating. In performing this last operation, the plasterer is provided with a substantial straight-edge, fre quently from ten to twelve feet in length, which must be handled by two workmen. All the parts to be floated are then tried by a plumb-line, to ascertain whether they are per fectly flat and level ; and wherever any deficiency appears, the hollow is filled up with a trowel-full, or more, of lime and hair only ; this is termed filling-out; and when these prelim inaries are settled, the screeds are begun to be formed.
6. A screed signifies a style of lime and hair, about seven or eight inches in width, gauged quite true by drawing the straight-edge over it till it is so. These screeds are made at the distance of about three or four feet from each other, in a vertical direction all round the partitions and walls of a room. When they are all formed, the intervals are filled up with lime and hair, called by the workman stqT, til! they arc flush with the face of the screeds. The straight-edge is then worked horizontally over the screeds, by which all the super fluous stuff, projecting beyond them in the intervals, is re moved, and a plain surface is produced. This operation is
termed floating, and may be applied to ceilings as well as partitions or upright walls, by first forming the screeds, hi the direction of the breadth of the apartment, and filling up the intervals as above described. As great care is requisite in this kind pf work, to render the plaster sound and even, none but skilful workmen should be employed upon it.
7. The set to floated work is performed in a mode similar to that already prescribed for laying ; only, as it is employed for best rooms, it is done with more care. There is also added to it about one-sixth of plaster of Paris, to make it set inure expeditiously, and give it a closer and more compact appearance, as well as to render it more firm, and better cal culated to receive the w hite-wash, or colour, when dry. For floated stucco work, the pricking-up coat cannot be too dry ; but, if the floating that is to receive the setting coat be too dry before the set is laid on, there will be danger of its peel ing off, or of its assuming the appearance of little cracks, or shells, which would disfigure the work. Particular attention is therefore to be paid to have the under-coats in a due state of dryness when the exterior surffice is laid on. And here it may also be remarked, that cracks and other unpleasant ap pearances in ceilings arc more frequently the effect of weak ness in the laths, covered with too much plaster ; or, on the contrary, of too little plaster upon strong laths, than of any sagging, or other inadequacy in the timbers of the building. If the laths be properly attended to, and the plastering laid on by it judicious careful workman, no cracks are likely to appear.
S. Rendering, and set, or rendering floated, and set, com bines both the foregoing processes, only it requires no lath ing. Rendering is to be understood of a wail, whether of brick or stone, being covered with a coat of lime and hair ; and by set is denoted a superficial coat, upon the rendering of fine stuff ur putty. These operations are similar to those described for setting of ceilings and partitions; and the floated and set is laid on the rendering in the same manner as on partitions, &c., as above explained for the best kind of (irk.