So that the servants' stair requires twenty-seven steps, and the grand staircase thirty-two: but the space or area required to execute the common would not be much less than that required to execute the grand staircase; the common stairs must therefore have two revolutions in the height. This being allowed, will reduce the area to half of what it otherwise would have required.

We must, however, observe that, when the height of the story is less than fourteen feet, the stairs will not admit of two revolutions.

In planning a large edifice, particular attention must be paid to the situation of the stairs, so as to give the most convenient and easy access to the several rooms.

137. With regard to the lighting of a grand staircase, a lantern-light, or a sky-light with a horizontal light under it, is the most appropriate. By introducing these, more effect is produced, and the light admitted is more powerful; but, indeed, where one side of the staircase is not a portion of the exterior wall, a lantern or skylight is the only way in which the light can be admitted.

138. In stairs constructed of stone, the steps are made of single blocks; quarter-spaces and half-spaces are, however, often made in two or more pieces, and joggled together: but, when the material is wood, the risers and treads must be made of boards, which are fastened together with glue, brackets, and screws; and these, though done with the utmost care, can never be made so firm as not to yield a little to the passenger.

To prevent stairs from becoming ricketty, in length of time, the steps must have an additional support under them; and that the appearance may be both light and pleasant, the whole must be confined to as small a space as possible. This additional wood-work, which is necessary to the firmness and durability of the construction, is called the CARRIage of the stair.

139. The carriage of a stair usually consists of several pieces framed together; and each flight of steps is generally supported by two pieces of timber, placed under the steps, and parallel to the wall, being fastened at one or both ends to pieces perpendicular to the walls. The pieces of timber which are thus placed under the steps are called rough strings. 140. DOG-LEGGED STAIRS are those which have no well-hole, and consist of two flights, with or without winders. The hand-rail, on both sides, is framed into vertical posts, in the same vertical plane, as well as a board which supports the ends of the steps. The boards are called STRING BOARDS, and the posts are called NEWELS. The newels not only connect the strings, but they afford the principal support to the rail; and thus it may be affirmed that the newels, posts, and hand-rail, are all in one plane. (See plate LXX.)

141. OPEN-NEWELLED STAIRS are those which have a rectangular well-hole, and are divided into two or three flights.

142. BRACKETED STAIRS are those where the string-board is notched, so as to permit the risers and treads to lie upon the notches, and pass over beyond the thickness of the stringboards the ends of the steps are concealed by means of ornamental pieces called BRACKETS. Geometrical stairs (defined art. 121) are generally bracketed; but, in dog-legged and opennewelled stairs, only those of the best kind are bracketed.

143. A PITCHING-PIECE is a piece of timber wedged into the wall, in a direction perpendicular to the surface of that wall, for supporting the rough strings at the top of the lower flight, when there is no trimmer, or where the trimmer is too distant to be used for the support of the rough strings.

144. BEARERS are pieces of timber fixed into, and perpendicular to, the surface of the wall, for supporting winders when they are introduced; the other end of the bearer is fastened to the string-board.

A NOTCH-BOARD is a board into which the ends of the steps are let: it is fastened to the wall, or one of the walls, of the staircase.

145. CURTAIL-STEP is the lowermost step of stairs, and has one of its ends, next to the wellhole, formed into an ornament representing a spiral line.

These are the principal parts which belong to a stair or stairs; other parts connected with it belong to the HAND-RAIL, and will be all defined in treating of Hand-railing.

Construction of Dog-Legged Stairs.

146. HAVING taken the dimensions of the stair, and the height of the story, lay down a plan and section upon the floor, to the full size, according to the design representing all the newels, string-boards, and steps; by this method the exact lengths and distances of the parts will be ascertained, as also the angles which they make with each other. The quantity of head-room, the situation of apertures and passages, and whether quarter-spaces, half-spaces, or winders, are to be introduced, having been previously settled on the drawing.

In order to have the most variety in the construction, we will suppose the stairs to have two quarters of winders; the whole being represented as framed together, the string-board will show the situation of the pitching-pieces, which must be put up next in order, by wedging the one end firmly into the wall, and fixing the other end into the string-board; which, being done, put up the rough-strings, and put up the carriage part of the flyers. In dog-legged staircases the steps are seldom glued up, except in cases where the nosings return; we shall therefore suppose them in separate pieces, and proceed to put up the steps.

Place the first riser in its intended situation, fixing it down close to the floor, the top at its proper level and height, and the face in its true position. Nail it down with flat-headed nails, driving them obliquely through the bottom part of the riser into the floor, and then nailing the end to the string-board.

Place the first tread over the riser, observing to give the nosing its proper projecture over the face of the riser; and, to make it lie more solid upon the string, notch out the wood at the farther bottom angle of the riser, where it is to come in contact with the rough-strings, so as to fit it closely down to a level on the upper side, while the under edge beds firmly on the roughstrings at the back edge, and to the riser at the front edge: nail down the tread to the roughstrings, by driving the nails from the place on which the next riser stands, through that edge of the riser, into the rough-strings, and then nailing the end to the string-board.

Begin again with the second riser; which, being brought to its breadth, and fitted close to the top of the tread, so that the back edge of the tread below it may entirely lap over the back of the riser, while the front side is in its real position. Then nail the tread to the riser from the under side, taking care that the nails do not go through the face, which would spoil the beauty of the work.

Proceed with riser and tread, alternately, until the whole of the flyers are set and fixed. Having finished the first flight of steps, fix the top of the first bearer for the winding-tread on a level with the last parallel riser, so that the farther edge of this bearer may stand about an inch forward from the back of the next succeeding riser, for the purpose of nailing the treads to the risers, upwards, as was done with the treads and risers of the flyers. The end of this bearer being fitted against the back of the riser, and having nailed or screwed it fast thereto, fix then a cross-bearer, by letting it half its thickness into the adjacent sides of the top of the riser, and into the top of the long bearer, so as not to cut through the horizontal breadth, nor

through the thickness of the riser, which will weaken the long bearer, and injure the appearance of the work: then fix the riser to the newel.

Try the first winding step-board to its place; then, having fitted it to its bearings, and to the newel, with a re-entrant angle, or bird's mouth, fix it fast. Proceed with all the succeeding risers and step-boards until the winders are complete.

Having finished the winders, proceed with the retrogressive or upper flight, exactly in the same manner as has been done with the lower flight.

The workman must then proceed to strengthen the work in the following manner: fix rough brackets into the internal angles of the risers and step-boards, so that their edges may join upon the sides of the rough-strings, to which they are fixed by nails, and thus the work is completed. 147. In plate LXX, figure 1, is represented a Dog-legged Stair with flyers only; that is, which consists of steps of equal breadth of tread. No. 1 is the Plan, showing the length and tread, or breadth of the steps; or that which shows their exact area; the dotted lines show the lines of the fronts of the risers. No. 2, the Elevation, shows the sections or ends of the steps. Figure 2 represents a DOG-LEGGED STAIR with winders, connecting the two straight flights. No. 1 is the Plan, showing the areas of the treads of the steps, as before. No. 2, the Elevation, shows the ends of the steps in the two flights, and the risers in both quarters of the winders.

148. It is proper to remark that, in the best dog-legged stairs, the nosings are returned, and sometimes the risers mitred to the brackets, and sometimes mitred with quaker-strings. In this case, a hollow must be mitred round the internal angle of the under side of the tread and face of the riser. Sometimes the string is framed into a newel, and notched to receive the ends of the steps; and, at the other end, a corresponding notch-board, and the whole of the flyers are put up in the same manner as a step-ladder.

By paying proper attention to what has here been said, a workman of good understanding will be able to execute such stairs, and put them up in the most sufficient manner, although he might never have seen one made or put up before.

Bracketed Stairs.

149. HERE the same method of laying down the plan and section must be observed as in dog-legged stairs. The balusters must be neatly dovetailed into the ends of the steps, two dovetails being put in each, in such a manner that one of the balusters may have one of its faces in the same plane with the riser, and the other face in the same plane with the face of the bracket.

Geometrical Stairs.

150. THE steps of Geometrical Stairs ought to be neatly finished, so that they may present a handsome appearance. The riser and step-boards ought not to be less than one inch and a quarter thick. The risers and step-boards ought to be well glued and secured together, with blockings glued in the internal angles. When the steps are set, the risers and step-boards must be fixed together by screws, passing from the under side of each horizontal part into the riser. The brackets must be mitred to the risers; and the nosings, with a cavetto underneath, should be returned upon the brackets, and stopped upon the string-board. The under side may be finished with lath and plaster. In many old buildings, where the principal stairs were