1868.] Foundations. 407 inches thick ; allowing it a fall of at least eighteen or twenty feet, into the trenches ; and there need be little appre- hension of a subsidence. There is no necessit% whatever, for planking such a foundation. Lay on large bedding-stones crosswise — as al- ready described — bedding them well on the concrete, and flushing their joints with cement. Now proceed in the usual manner ; and you have a foundation, at once economical and everlastingly secure. Nature reads us another lesson in this ; for, she forms her hardest and most enduring rocks of concrete. In another paper we will discuss the merits of this material ; and the best manner of composing it ; our business, in the present, being with Foundations, as we find them, in course of construc- tion ; or, as in the past. Some architects commence laying brick immediately over the bedding- course. This we do not consider a good practice, for, if b} r any chance a bedding- stone should settle, in the slightest de- gree, the thickly jointed brick courses over it, all the way up, would catch the infection ; and a palpable fracture must be the necessary consequence. No— these bedding-stones should be securely bridged by large stones, laid the reverse of their beds, and the joints cautiously broken. And such course should be covered, or guarded, by still another course, equally well constructed, with a view to unity and strength. Then the brick-work may be laid for five courses ; and have a five-inch course of blue- stone, or granite, covering the whole thickness of the wall. It would not be amiss to dowel these stones together with two sets of dowels, parallel to each other, thus forming, at every five courses of brick-work, a thorough bond, that would give unusual strength, and resist- ance to settlement. All this, too, below the level of the cellar floor. In fact, the main point to be observed in the construction of foundations, is the employment only of indestructible materials, in such a manner, as to pro- duce as complete a combination of strength as possible. The Roman architects had recourse to still another mode of construction, which was by means of Reticulated Brick-work. In this kind of work, the individual bricks of each course are laid apart, nearly their own width, thus having apertures, or interstices, between all the bricks of the structure, arranged checker-board fashion, the bricks repre- senting the white squares and the holes the black ones. This method is often used in the ventilating windows of brick stables. The brick used in such cases was vitrified, and in very per- fejtly moulded cubes ; every fourth course being flushed and leveled, with half cubes, cast for that purpose, over which four horizontal courses of a longer brick were laid ; and, then, four reticu- lated courses ; and, again, four horizon- tal courses ; thus continuing up, until the surface of the ground was reached. Provided the stratum is a stiff clay, at least, on which such a foundation rests, it must be obvious, that settling is to be expected, as every thing depends on the first course ; and should there be a soft spot in the upbearing stratum, however small that spot, it will be suffi- cient to derange the whole. Reticulated work may be seen, in superstructures, in many parts of Eu- rope, at this day. But, for foundations, the adventurous Romans themselves had little faith in reticulated work. Civil and military engineers employ other modes of constructing founda- tions, where works are very extensive, and the location swamp}', or sandy, as in the case of piers, sea-walls, railroads, &c. Both ancient and modern practice includes : Building on Fascines, or, bundles of ivood, laid crosswise of each other, and filling in, over them, with loose stones and gravel ; Building with Loose Stones confined in Cribs, made of
