1. Slate stone is valuable for the property of splitting in one direction, so as to afford fragments of a sufficient size and thinness to answer several purposes, but especially for covering houses and for writing slates. The best slates are those which are even and compact, and which absorb the least water. 2. The slates used in the United States, are obtained either from our own quarries, of which there are several, or from those of Wales, in the county of Caernarvonshire. The stone is quarried in masses, which are afterwards split into pieces of suitable thinness. These are trimmed to an oblong figure by means of a knife and a steel edge, which act upon the slate much in the manner of a large pair of shears. 3. As it is impossible to dress all the slates to the same size without much waste of material, those engaged in their manufacture have introduced several sizes, the smallest of which are made of the fragments of the larger kinds. These are designated by names known to the trade, and to those practically conversant with the art of building. 4. The slates, when brought to market, especially those from Wales, require additional dressing to fit them for use. The manner of applying them to roofs differs but little from that employed in putting on shingles, as they are lapped over each other in the same way, and confined to their place by means of nails of a similar kind. The nails, however, have a broader head, and are somewhat larger, varying in size to suit the dimensions of the slate. The holes in the slate for the nails are made with a steel point attached to the slater's hammer, or to his knife, technically called a _saix_. 5. Slates are preferable to shingles on account of their durability, and, in a majority of situations, for their fire-proof quality. They, however, are objectionable on account of their weight and expensiveness, and are therefore beginning to be superseded in this country by sheets of zinc, and by those of iron coated with tin. Copper and lead are also used for roofs, but the metals just mentioned are beginning to exclude them altogether. 6. A serious objection to metal roofs has been their liability to crack, caused by the contraction and expansion of the material, in consequence of variations in the temperature of the weather; but a particular method of putting the sheets together has been lately devised, which appears to obviate the difficulty. Tiles are not used in this country, although in Europe they are very common. [Illustration: PAINTER & GLAZIER.] THE PAINTER, AND THE GLAZIER. THE HOUSE AND SIGN PAINTER. 1. The painting which is the subject of this article relates to forming letters and sometimes ornamental and significant figures on signs, as well as to the application of paints to houses and other structures, for the purpose of improving their appearance, and of preserving them from the influence of the atmosphere and other destructive agents.