United States or Isle of Man ? Vote for the TOP Country of the Week !
T. Wilson served as engineer in carrying out his design. The details differed in several important respects from the proposed bridge of Paine, Mr. Burdon introducing several new and original features, more particularly as regarded the framed iron panels radiating towards the centre in the form of voussoirs, for the purpose of resisting compression. Mr.
By careful moulding and manipulation the Assyrian builder made his brick voussoirs as well fitted for their work as the cut stone of our day. Each brick had its own shape and size, so that it was assigned in advance a particular place in the vault and its own part in assuring the final stability of the building.
§ X. The reader now understands all that he need about the shell of the arch, considered as an united piece of stone. He has next to consider the shape of the voussoirs.
Over bridges and tunnels it sometimes approaches to the condition of mere dust or yielding earth; but in architecture it is mostly firm masonry, not altogether acting with the voussoirs, yet by no means bearing on them with perfectly dead weight, but locking itself together above them, and capable of being thrown into forms which relieve them, in some degree, from its pressure.
The pavement of the terrace, which consists of a double bed of large bricks, rests upon the extrados of the upper channel. This vault is semicircular; it has three voussoirs on each side, which, with the key, make seven in each vertical course.
The voussoirs, thinking their great adversary utterly defeated, are at no trouble to show themselves; visible enough in both the upper and under archivolts, they are content to wait the time when, as might have been hoped, they should receive a new decoration peculiar to themselves. § XI. In this state of paralysis, or expectation, their flank is turned by an insidious chamfer.
The horizontal lines of the latter become semicircular, but their importance and value remain exactly the same; their continuity is preserved across all the voussoirs, and the joints and functions of the latter are studiously concealed.
This, the manliest and best condition of the early northern jamb and archivolt, is represented in section at fig. 12 of Plate II.; and its simplest aspect in Plate V., from the Broletto of Como, an interesting example, because there the voussoirs being in the midst of their above-described southern contest with the architrave, were better prepared for the flank attack upon them by the shaft and chamfer, and make a noble resistance, with the help of color, in which even the shaft itself gets slightly worsted, and cut across in several places, like General Zach's column at Marengo.
It has only two orders left, of which the outer, though under a deep arch, has a billet-moulded drip-mould, and its voussoirs each carved with a figure on the outer and delicate flutings on the under side, while the inner has on both faces animals and monsters which, better wrought than those at Villar, are even more like so many in the south-west of France.
Marble was much favored for this purpose because it harmonizes with the white-painted woodwork, brightens the façade and emphasizes the fenestration. Most of the lintels take the shape of a flat, gauged arch with flutings simulating mortar joints that radiate from an imaginary center below and mark off voussoirs and a keystone.
Word Of The Day