One of the most simple and effective yet least common arrange ments of a staircase, is that which may be described by the term avenue staircase, the stairs being continued in a straight line, though broken by spaces into a succession of flights, within what would else be a level corridor or gallery ; and occupying its entire width. There is something particularly noble and majestic in a staircase of this kind, for although it may be narrow, considered as 'a gallery, it looks unusually spacious as a staircase, the flight itself being wider than those of staircases placed within a much larger area ; besides which, the whole is more regularly disposed, and forms a more striking piece of perspective. Still, simple as such plan is in itself, it is by no means adapted to general application, because, although it requires only moderato width, it requires considerable length, short flights, and ample spaces between them, and stairs with low risers and broad treads ; otherwise, the descent, as viewed from above, being in a s straight line, looks precipitous, or at least has no dignity of appear ance. Another circumstance which limits a staircase of this kind to cases, is, that in order for it to produce proper effect, the eight to be ascended should be very moderate, hardly more than seven or eight feet ; for else, the space at the foot of the stairs looks confined, and the upper flights scarcely show themselves from that station. Hence, though it may be referred to as an Instance of an avenue staircase, the one leading to the keep or round tower at Windsor Castle, is more remarkable than beautiful or grand, leaving decoration out of the question ; the altitude ascended being so very great. Sir John Soaue has given some ideas of the kind in his designs for a ' Scala Begin '—a favourite subject with him. The staircase of the Chamber of l'eers at Paris, designed by Percier and Fontaine, was an example of the kind, but not the beet, for the ascent was so great that the columns on its sides, on the same level as the landing, looked quite insignificant. The National Gallery, again, afforded instances of a different modification of the same arrangement, half the ascent being by an external flight in the vestibule, the remainder by another within the corridor leading from it ; and though not exactly suited for such a building, the idea is platting in itself and would produce a striking effect, in one of loss pretension.
In public edifices or large mansions, whatever be the plan of the principal staircase, it is generally branched, that Is, there is first a wide central flight, and then two other narrower ones branching off from it one on each side, either at right angles to it or as return flights parallel to it ; and It is hardly necessary to observe, that in all ouch staircases the fool-spates are large, and that there are no winders. Extreme care should, however, be Laken in planning staircases of this (or indeed of any) description for places of public resort, as theatres, concert rooms, &c., to so design them as to produce the least possible hindrance to the rapid passage of the audience in case of the occurrence of a panic. The branched staircase at Goldsmiths' Hall, which is parted off from the vestibule by a glazed screen, is an example of more than ordinary splendour, being lighted by a dome. The branching flights at right angles to the first, lead to a landing on each aide, which has a double screen of Corinthian columns, so that the view across from side to side, in the upper part, is unusually rich. At Buckingham Palace, there is first a very wide Hight, entered from between columns, branching off right and left in curved flights, the cage, which is about 36 by 26 feet, being curved elliptically on those. sides or ends. In this example, the stairs rest upon a graduated podium or wall enclosing the space immediately beneath, which serves as a private passage behind ; a mode frequently adopted in similar cases, being one which contributes to solidity and nobleness of appearance, and pre vents that mass of shadow beneath the stairs which gives a gloom to the lower part of the staircase.
Instead of there being a central flight below, the ascent frequently begins on each side, and is carried up in ono or more flights to the common landing, where both branches terminate ; from which point the stairs are sometimes continued, returning in an upper central flight, which is carried across an arch thrown from that landing or half space, to a higher landing. Staircases of this kind, which may be termed
bridge staircases, occur in the Custom House and the Auction Mart. Their effect, however, is not good, because the upper suspended flight or bridge darkens the lower part of the staircase, and has a strangely awkward cumbersome appearance when viewed from that station. At the beat, therefore, they are suitable only for places of evening resort, where they can be lit up below as well as above.
The staircase of the Fitzwilliam Museum, Cambridge, claims notice, not only on account of the richness of. the general design, but of some peculiarities in its arrangement. Strictly speaking however, this example can hardly be given as that of a staircase, according to the usual meaning of the term, the stairs being mere flights of steps in the entrance hall. That in the centre is a broad descending ono, lead ing down to the libraries, which are on a lower level than the hall; and on each side of it is a rather narrower ascending flight to the spacious landing carried around three sides of the hall, and serving as a statue gallery. Though the lower area is only 32 by 26 feet, conse quently that of the floor very much less, owing to the space occupied by the flights of steps, that of the upper part on the level of the land ing is 68 by 44 feet, the landing itself being about 17 feet wide. In some degree similar in plan, although very different in design, is the hall at Holkhain, the seat of the Earl of Leicester, which has a noble flight of steps within a recess or tribune enclosed by columns which are continued along the aidca of the hall.
The grand staircase of the Reform Club-house, London, is an example, somewhat unusual In this country, though common enough in Italy, of what may be called an enclosed staircase; the flights are shut up between walls, and consequently there is no open irc//, nor can the whole be seen at one view. A plan of this kind therefore differs from the avenue staircase, merely in not being carried straight-forward, but either returning in a parallel flight from the half-space or first landing, or having the second flight at right angles with the first. The last is the case at the Reform Club-helium, where the staircase consists of three enclosed flights, the last being a return one to the first, and landing upon the gallery around the upper put of the inner hall or saloon. That at Burleigh too is similarly planned. The same mode may be adopted for circular or semi-circular as well as rectan gttlar plans ; end one advantage attending it is, that while the ascent itself is as spacious and commodious as if the whole were entirely open, there may be a secondary staircase for servants, shut up within the larger one.
The architectural effect of a staircase will greatly depend upon the mode of lighting IL Where it is carried up only one floor, the beat mode is to light it entirely from above, either through a dome or lantern in tho ceiling, or by making the upper part of the walls just beneath the ceiling a continued lantern. If there are windows on the landings of the several flights, the effect will be improved by their being filled with stained glass, especially if towards a back court ; or, if a conservatory can be carried out on the level of the first landing, so as to show itself through glazed folding-doors, a very pleasing and cheerful effect is obtained, even though the conservatory itself should be hardly more than a glazed veranda. As to material, stone is greatly preferable to wood for stairs, if only on account of greater security in case of fire; in lieu of stone, cast-iron may be employed. Marble in very rarely used for stairs in this country, and whenever it is, it ehould be left unpolished on the treads, or it would be dangerous to descend theta. The same remark applies to stairs of wainscot, unless they are carpeted nearly their entire width.