The separate stones which compose the arch are called voussoirs or arch-stones; the extreme or lowest voussoirs are termed springers, and the uppermost or central one is called the keystone.
The under or concave side of the voussoirs is called the intrados, and the upper or convex side the extrados of the arch.
It has been employed in building ever since; but never in solid and in the gross as a constituent part of the substance of building before Mr. Rennie employed it as voussoirs in the Southwark Bridge.
The only voussoirs used are in the face of the arches.
Tiles are not used in the Tower, but some of the older arches of the arcade on the top floor have voussoirs of rag, evidently continuing the tradition of tiles.
The voussoirs of the arches at Falaise, Domfront, and Rochester are larger than the rag or tile voussoirs which are used at Colchester, the Tower, and Langeais.
In the second storey there are three rather small windows and one very large one;[1118] they are round arched, have no splay, and their voussoirs are of narrow stones alternated with tiles.
He says further: that the lower voussoirs which are in the northern and southern angles ought to be altered, and that they ought to be reconstructed in accordance with the plan of three naves.
Whether, in case the plan of three naves is carried out, there will be any danger in opening a hole in the pillar over the pulpit corresponding to the other of the Coro at the time of joining the voussoirsabove the capital?
It is of marble, of two well-moulded orders, and the outer order of the arch has voussoirs of grey and white marble counterchanged.
The voussoirs of the centre arch (all of granite) are 4 ft.
For sewer work and arches, bricks shaped as voussoirs are supplied.
To give stability the sides of the voussoirs are gauged out hollow and grouted in Portland cement, thus connecting each brick with the next by a joggle joint.
The difficulty of casting heavy arch ribs led to the construction of cast iron arches of cast voussoirs, somewhat like the voussoirs of masonry bridges.
The arch of the bridge fell (two voussoirs still remain), smashing in part of the arch of the aqueduct.
In this west front of San Francesco the cornices and the mouldings of the small circular windows are all of brick, and the rest of the front of stone, the rose window having voussoirs of black and white marble.
All the arches have occasional voussoirs of stone, and the centre of the arch is always marked by a key-stone, and these are sometimes slightly carved to distinguish them from the other stone voussoirs.
It is built entirely of red brick, not relieved in any way, except that the window arches are in alternate voussoirs of brick and stone.
In its construction pointed and round arches have been used quite indiscriminately, and in some of the arches the depth of the voussoirs increases towards the centre of the arch.
Stone is used very sparingly in the voussoirsof the arches and elsewhere.
They consist of three orders--the two inner formed of alternate voussoirs of brick and stone, carefully and regularly counterchanged, and the outer of a moulded terra-cotta ornament.
The proportion of voussoirs to arches naturally depended upon the size of the arch,--large voussoirs to large arches, small voussoirs to small arches.
This vault is semicircular; it has three voussoirs on each side, which, with the key, make seven in each vertical course.
By careful moulding and manipulation the Assyrian builder made his brickvoussoirs as well fitted for their work as the cut stone of our day.
The first course of voussoirs would be sloped in this fashion, and would rest upon some mass of crude brick in the centre of the building.
The two rows ofvoussoirs that are in full view thrust against each other only by a single sharp edge; there is no keystone between them.
Hence, if the piers at the ends are of large dimensions, they will hold the voussoirs together, and make such works durable.
We must also manage to discharge the load of the walls by means of archings composed of voussoirs with joints radiating to the centre.
In the Mahommedan style the doorway itself is comparatively simple, except that the voussoirs of its lintel are joggled with a series of curves, and being of different coloured stones have a decorative effect.
In a sense, they are not true domes, because they are built in horizontal courses of stone, which act like the voussoirs of an arch in resisting the thrust of the earth at the back.
This dressing also occurs on the stones of the voussoirs of the great TyropA|on bridge, an indication which I have never seen noticed before.
Here also we have proof that the Crusaders themselves hewed stones with a marginal draft and a rude rustic boss, for no old materials are used up in 'AthlA(R)t, and drafted stones occur even in the voussoirs of the pointed arches.
Generally the arch is divided into an uneven number of voussoirs so as to give a keystone, the voussoirs being laid from each side of the keystone and fitting exactly in the centre of the arch.
In some cases two or more voussoirs are of one stone, having a false joint cut in the centre; this is economical, and in some cases adds to the stability of the arch.
The voussoirs are connected by joggles worked on their joints, as in fig.
The keystone is not a necessity, arches being frequently formed with an even number of voussoirs; some architects hold that the danger of the voussoirs cracking is thereby lessened.
In the case of arches these layers should be parallel with the centre line of the voussoirs and at right angles to the face of the arch.
The two upper voussoirs meeting and touching one another by one of their corners, the triangular space left empty between their edges was filled up either by wedge-shaped bricks or by mortar.
In their disinclination to use stonevoussoirs the Assyrian builders here found themselves compelled to mould bricks of very complicated form, and the way in which they accomplished their task speaks volumes for their skill.
All the voussoirs, which have issued from a single mould, have a slightly trapezoidal shape, like the stone voussoirs of our most carefully built edifices.
The arch of the door, which is set in the second decorated zone of the tower, consists of a double row of half-bricks laid vertically and an outer belt of brick voussoirs laid horizontally.
The arches over the outer doorway and over the interior niche are composed of a course and a half of tiles laid vertically and an outer ring of brick voussoirs laid horizontally.
When it was wider an outer arch of voussoirs laid horizontally encompassed the inner concrete arch.
When the arches are of wide span an outer ring of horizontal voussoirs is added to the inner arch.
The arch is set back from the jambs and formed of an inner ring of concrete and an outer ring of stone voussoirs laid horizontally.
Each niche is covered by a triply recessed arch, roughly constructed of half-bricks set in rings, not as voussoirs (Plate 47, Fig.
Each of the three members of the arch is recessed behind the other, the outer voussoirs being flush with the face of the wall.
The voussoirs of the arch are not all of equal size in each order, and on one member the chevrons are reversed on opposite sides of the centre stone except for one accidental intermission.
And that, though the twelfth-century voussoirs were re-used others of a fine grained stone were inserted among them to strengthen the arches, or as a substitute for some of the rougher sandstones that could not be used again.
Moreover, in a number of fan vaults as well as in others of different type, pendantvoussoirs or keystones are employed.
But as this may perhaps throw the arch inconveniently high, or occasion a waste of voussoirs at the top, we may employ another expedient.
In the above reasonings, the inclination of the joints of the voussoirs to the curves of the arch has not been considered.
Whatever its form, if we merely let the ends of the bars into the voussoirs of its heading, the least settlement of the masonry would distort the arch, or push up some of its voussoirs, or break the window bars, or push them aside.
Now the arch line is the ghost or skeleton of the arch; or rather it is the spinal marrow of the arch, and the voussoirs are the vertebræ, which keep it safe and sound, and clothe it.
If still it be not strong enough, a farther addition may be made, as at c, now thickening the voussoirs a little at the base also.
But the voussoirs then concede, on the other hand, so much of their dignity as to receive a running ornament of foliage or animals, like a classical frieze, and continuous round the arch.
It is easily conceivable that when two ranges of voussoirs were used, one over another, it would be easier to leave those beneath, of a smaller diameter, than to bevel them to accurate junction with those outside.
The variation of the mortar used in their construction from white mortar in the jambs to pink mortar in the voussoirs of the arch is a very noticeable feature, and can be exactly paralleled in the Roman Pharos at Dover.
The Matriz at Vianna has a fifteenth-century pointed door, with half figures on the voussoirs arranged as are the four-and-twenty elders on the great door at Santiago, a curious arrangement found also at Orense and at Noya.
The earliest example known of the arched vault, with regular voussoirs in stone, is found in the canal of the Marta near Graviscae, ascribed to the 7th century.
Both in Belgium and Holland there are numerous examples of domestic architecture in brick with quoins and tracery in stone, in both cases alternating with brick courses and arch voussoirs and with infinite variety of design.
In the building of an arch, the voussoirs have to be temporarily supported, until the keystone is inserted.
This at the present day is effected by means of centreing an assemblage of timbers framed together, with its upper surface of the same form as the arch required; the voussoirs are laid on the centreing till the ring of the arch is completed.
The Assyrian tradition would seem to have descended first to the Parthian builders, who in the palace of El Hadr built semicircular arches with regularvoussoirs decoratively treated.
The bricks employed in these ribs, and for the voussoirs of arches, were of the kind we should describe as tiles, being about 2 ft.
The experiments of Rondelet and others have proved that the voussoirs unite into segments of the arch, and tend to overturn the abutment, acting rather as levers than wedges.
He found, also, that the greatest thrust was in arches with an even number of voussoirs or a point at the vertex; that a keystone lessened the thrust.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "voussoirs" in a variety of sentences. We hope that you will now be able to make sentences using this word.
