PAVING, or PAVEMENT. A layer or covering of stone or brick, carefully laid over roads, paths, halls, passages, &O., and to form stone floors in the interior of buildings. Pavements of flint and flags, in streets, are commonly laid dry, that is, in beds of sand or gravel ; those of stables, courts, ground rooms, &c. are laid in a mortar of lime and sand, or in lime and cement, especially if there be cellars underneath. Sometimes, after a floor of stone or brick has been laid dry, a thin stratum of mortar is spread over it, and worked into the crevices, to fill up all the joints. The several kinds of paving are as various as the mate rials of which they are composed, the adoption of which depends usually upon local circumstances and the expense : the following are the principal kinds.
1. Pebble-paving, frequently laid in ornamental design, is done with kidney shaped stones, obtained from Guernsey and other places; it is extremely durable when properly performed.
2. Rag-pavi ng, formerly much used in London : the stone is obtained from Maidstone, in Kent, whence the name of Kentish rag-stone; there are square stones of this material for coach-tracks and footways.
3. Purbeck pitchens; stones from six to ten inches square, and five inches deep, brought from the island of Purbeck, and frequently used in court-yards.
4. Square-paving, by some called Scotch-paving: by this was recently under stood cubical stones, of blue whynn ; they are, however, now nearly disused in London, owing to their inferiority of the next-mentioned.
5. Scotch granite ; a hard material, usually of a bluish or reddish colour, with which the London road-pavements are formed.
6. Guernsey and Herm blue-granite ; extensive quarries being now opened at the latter island, chiefly for the supply of the London pavements, for which purpose it is found to answer as well, if not better, than the Scotch. The atones are prepared of a prismoidal figure, by means of iron hammers, and are usually laid with their end downwards, bedded in gravel 7. Purbeck-paving, of the blue sort, in large surfaces, and about 21 inches thick, make excellent flag pavements.
8. Yorkshire-paving, of large dimensions, is equally good with the former, is impervious to water, and unaffected by frost.
9. Ryegate, or firestone-paving, is used for ovens, and such places as are liable to great heat, which does not affect the stone, if kept dry.
10. Newcastle flags are about two feet square, and two inches thick: answer well for out-offices.
11. Portland-paving, from Portland, sometimes interspersed with black dots.
12. Swedland-paving is a black slate, dug in Leicestershire ; much used in paving halls, especially in party-coloured paving.
13. Marble-paving, frequently variegated with different coloured in whits, and sometimes inlaid in mosaic.
14. Flat-brick paving, done with brick laid in sand and mortar, or groute, as when liquid lime is poured into the joints.
15. Brick-on-edge paving, done with brick, laid edgeways, in the same manner.
16. Bricks laid fiat or edgeways, arranged in herring-bone fashion.
17. Bricks set endways in mortar, sand, or groute.
18. Paving-bricks, made especially for the purpose.
19. Paving with ten-inch tiles.
20. Paving with foot tiles.
21. Paving with clinkers, for stables, &c.
There are many other kinds of paving, equally worthy of notice with the foregoing, but it would be needless to extend the description. We must not, however, omit to mention a beautiful imitation of mosaic, in various colours and designs, now manufactured of pottery-ware, some specimens of which we have seen at the Museum of National Manufactures and the Arts, in Leicester-square. Pavements of churches and other handsome buildings fre quently consist of stones of various colours, but chiefly black and white, in squares or lozenges, artfully disposed. There needs no great variety of colours to make a surprising diversity of effect. It has been shown, that two square stones, divided diagonally into two colours, may be joined together, in checkers, sixty-four different ways, as each admits of four different situations, in each of which the other square may be changed sixteen times, which gives sixty-four combinations. A very beautiful example of a tesselated pavement, in black and white, is afforded in the extended floor of St. Paul's Cathedral, which is well worthy of examination by those who have occasion for works of that nature.