296

EXPOSITION AT VIENNA.

try, has been the supposed difficulty of setting them prop­erly. In the large cities the agents usually keep experi­enced men in their employ, -who can lay down the tiles if desired. A few simple directions will, however, enable any skilful mason to fix them properly.

The foundation must be firm and secure in all cases, so that there shall no't be any settling or absence of equal support under all parts of the pavement. Cement mortar, without sand, is used in setting the tiles, so that a perfect bearing is obtained and all the joints are filled. The fol­lowing directions are copied, with only slight modifications, from those published by Messrs. Minton, Hollins & Co :—

1. If there is no cellar or other opening underneath the space intended for the tile pavement, the foundation may be brought up to within three inches of the proposed surface of the pavement with brick, gravel, broken stone, clean stone clippings, or other solid waste sub­stances free from chips and shavings, so that complete solidityqmay be secured. Upon this substratum a mortar of gravel and cement should be spread, leaving a depth of one inch for half-inch tiles, and of one’and a half inches for one-incli tiles. A floating of cement and sand, in equal proportions, should then be spread one-quarter of an inch thick, over the cement and gravel layer. Upon this, when hard, the tiling may be fixed.

2. The above method is equally applicable, as far as requisite, to places above a cellar or other opening below, provided a firm founda­tion is given by an archway of brick or stone, or other equally solid substance. But when there is only an ordinary floor or floor-joist, it is necessary that the surface of this floor should be four inches lower than the surface of the intended pavement. There being, at that depth, a strong flooring of plank or rough boards, the mixture of cement and gravel, as above, may be spread upon it, and finished in the same manner.

3. Where it is required to replace boarded flooring by tiles, and it is impracticable to lower the joists to the necessary depth, as mentioned in 2, the floor boards maybe lowered by “ cutting in” between the joists, securing them below by strips nailed to the sides of the joist, so as to leave a space three inches deep above the boards, and below the top of the joists. The space so obtained is then to be filled in between the joists with the; Cement and gravel mortar, raising it slightly above the joists, and finishing off with cement and sand, as described in 1. A flat, level surface of this last coating may be secured by striking off with a straight edge, sup-