Bracket stairs are those that have an opening or well, with strings and newels, and are supported by landings and carriages, the brackets mitering to the ends of each riser, and fixed to the string-board, which is moulded below like an architrave.
The same methods must be observed as to taking the dimensions of bracket stairs, and laying down the plan and section, as in dog-legged stairs. In all stairs whatever, after having ascertained the number of steps, take a rod, the height of the story from the surface of the lower floor to the surface of the upper floor : divide the rod into as many equal parts as there are to be risers, then if you have a level surface to work upon below the stair, try each one of the risers as you go on, this will prevent any excess or defect, which even the smallest difference will occasion ; for any error, however small, when multiplied, becomes of considerable magnitude, and even the dilli•rence of an inch in the last riser being too high or too low, w will not only have a bad effect to the eye, but will be apt to confound persons not thinking of any such irregularity. In order to try the steps properly by the story rod, it' you have not a level surface to work from, the better way will be to lay two rods or boards, and level their top surilice to that of the floor, one of these rods being placed a little within the string, and the other near or close to the wall, so as to be at right angles to the starting line of the first riser, or, which is the same thing, parallel to the plan of the string ; set off the breadth of' the steps upon these rods, and number the risers ; you may set not only the breadth of the flyers, but that of the winders also. In order to try the story-rod exactly to its vertical situation, mark the same distances on the backs of the risers upon the top edges, as the distances of the plan of the string-board and the rods are from each other, [The methods of describing the scroll and all ramps and knees, are described geometrically in the articles ]AND RAILING and STAIRCAS1NG.] As the internal angle of the steps is open to the end, and not closed by the string, as in common dog-legged stairs, and the neatness of workmanship is as much regarded as in geometrical stairs; the balusters must be neatly dovetailed into the ends of the steps, two in every step ; the face of each front baluster must be in a straight surface with the face of the riser ; and as all the balusters must be equally divided, the face of the middle baluster must of course stand in the middle of the thee of the riser of the preceding step and the face of the riser of the succeeding one. The risers
and treads are all glued and blocked previously together; and when put up, the under side of the step nailed or screwed into the under edge of the riser, and then rough-bracketed to the rough-strings, as in dog-legged stairs, the pitching-pieces and rough-strings being similar to those, In gluing up the steps, the best method is to make a templet, so 41S to fit the external angle of the steps with the nosing.
Geometrical stairs.—The steps of Geometrical stairs ought to be constructed so as to have a very light and clean appear ance when put up : for this purpose and to aid the principle of strength, the risers and treads, when planed up, ought not to be less than 1-1- inch, supposing the going of the stair, or length of the step, to be 4 feet ; and for every 6 inches in length you may add part more; the risers ought to be dovetailed into the cover, and ‘N hen the steps are put up, the treads are screwed up from below to the under edges of the risers : the holes Cur sinking the heads of the screws ought to be bored with•a centre-bit, and then fitted closely in with wood, well matched, so as to conceal the screws entirely, and to appear as one uniform surface without blemish. Brackets are mitered to the riser, and the uosings are continued round : in this mode, however, there is an apparent defect, fur the brackets, instead of giving support, are themselves unsup ported, depending on the steps, and are of no other use, in point of strength, than merely tying the risers and treads of the internal angles of the steps together ; and from the inter nal angles being hollow. or a re-entrant right angle, except at the ends, which terminate by the wall at one extremity, and by the brackets at the other, there is a want of regular finish. The cavetto or hollow is carried all round the front of the slip, returned at the end, returned again at the cud of the bracket, thence along the inside of the same, and then along the internal angle of the back of the riser.