There should be at least as much room in the passage at the side of the stairs as upon them; and in regard to the length of the passage in the second story, there must be room for the doors which open from each of the principal rooms into the hall, and more if the stairs require it. Having assigned a position for the stairs of the second story, now generally placed in the centre of the depth of the house, let the winders of the other stories be placed perpendicularly over and under them; and be careful to provide for head-room. To ascertain this, when it is doubtful, it is well to draw a vertical section of the whole stairs; but in ordinary cases this is not necessary. To dispose the windows properly, the middle window of each story should be exactly in the middle of the front; but the pier between the two windows which light the parlor should be in the centre of that room; because when chandeliers or any similar ornaments hang from the centre-pieces of the parlor ceilings, it is important, in order to give the better effect, that the pier-glasses at the front and rear be in a range with them. If both these objects cannot be attained, an approximation to each must be attempted. The piers should in no case be less in width than the window openings, else the blinds or shutters, when thrown open, will interfere with one another; in general practice, it is well to make the outside piers 2/3 of the width of one of the middle piers. When this is desirable, deduct the amount of the three openings from the width of the front, and the remainder will be the amount of the width of all the piers; divide this by 10, and the product will be 1/3 of a middle pier; and then, if the parlor arrangements do not interfere, give twice this amount to each corner pier, and three times the same amount to each of the middle piers.
Fig. 20. Section.
Fig. 21. Elevation.