4 is from a little belfry in a Swiss village above Vevay; one fancies the window of an absurd form, seen in the distance, but one is pleased with it on seeing its masonry. It could hardly be stronger. § XII. These then are arches cut of one block. The next step is to form them of two pieces, set together at the head of the arch. 6, from the Eremitani, Padua, is very quaint and primitive in manner: it is a curious church altogether, and has some strange traceries cut out of single blocks. One is given in the "Seven Lamps," Plate VII., in the left-hand corner at the bottom. 7, from the Frari, Venice, very firm and fine, and admirably decorated, as we shall see hereafter. 5, the simple two-pieced construction, wrought with the most exquisite proportion and precision of workmanship, as is everything else in the glorious church to which it belongs, San Fermo of Verona. The addition of the top piece, which completes the circle, does not affect the plan of the beautiful arches, with their simple and perfect cusps; but it is highly curious, and serves to show how the idea of the cusp rose out of mere foliation. The whole of the architecture of this church may be characterised as exhibiting the maxima of simplicity in construction, and perfection in workmanship,--a rare unison: for, in general, simple designs are rudely worked, and as the builder perfects his execution, he complicates his plan. Nearly all the arches of San Fermo are two-pieced. [Illustration: Plate IV. ARCH MASONRY.] § XIII. We have seen the construction with one and two pieces: _a_ and _b_, Fig. 8, Plate IV., are the general types of the construction with three pieces, uncusped and cusped; _c_ and _d_ with five pieces, uncusped and cusped. Of these the three-pieced construction is of enormous importance, and must detain us some time. The five-pieced is the three-pieced with a joint added on each side, and is also of great importance. The four-pieced, which is the two-pieced with added joints, rarely occurs, and need not detain us. § XIV. It will be remembered that in first working out the principle of the arch, we composed the arch of three pieces. Three is the smallest number which can exhibit the real _principle_ of arch masonry, and it may be considered as representative of all arches built on that principle; the one and two-pieced arches being microscopic Mont-Cenisian, mere caves in blocks of stone, or gaps between two rocks leaning together.