STAIRS, (from the Saxon, stager,) in a building, the steps whereby to ascend and descend from one story to another.
The breadth of the steps of stairs in general use in com mon dwelling-houses, is from 9 to 12 inches, or about 10 inches at the medium. In the best staircases of noblemen's houses, or public edifices, the breadth ought never to be less than 12 inches, nor more than H. It is a general maxim, that the greater breadth of a step requires less height than one of less breadth : thus, a step of 12 inches in breadth will require a rise of 51 inches, which may be taken as a standard by which to regulate those of other dimensions; so that multiplying 12 inches by 51, we shall have 66 ; then supposing a step to be 10 inches in breadth, the height should be inches, which is nearly, if not exactly, what com mon practice would allow. The proportions of steps being thus regulated, the next consideration is, the number requisite between two floors or stories, which will be ascertained by supposing the breadth of the steps given, say 10 inches each, as depending on the space allowed for the staircase, and this, according to the rule laid down, will require a rise of 7 inches nearly ; suppose, then, the distance from floor to floor to be 13 feet 4 inches, or 160 inches : =227, which would be the number required ; but as all the steps must be of equal heights, we should rather take 23 rises, provided the staircase room would allow it, and so make the height of each some what less than 7 inches.
The most certain method of erecting a staircase is, to pro vide a rod of sufficient length to reach from one floor to the other, divided into as tummy equal parts as the intended number of rises; and try every step as it is set, to its exact height. The breadth of the staircase may be from 6 to 20 feet, according to the use or occupier of the building, or the form and proportions of the plan. If the steps be less than three feet in length, the staircase becomes inconvenient for the passing of furniture, as is frequently the case in small houses.
Though it is desirable to have such rules as are here laid down for regulating the proportions of the heights, breadths, and lengths of steps, architects and workmen cannot be so strictly tied to them, but that they may vary them as cir cumstances may demand.