The date of this staircase is not quite certain, but it probably belongs to the work which was being done about the year 1556. The idea of stone vaulted stairs, however, did not obtain any hold in England, and there are very few examples to be found. All the finest staircases are of wood, and they seem to have sprung into being without any gradual growth; the connecting links between them and the old corkscrew type, if there were any, have disappeared. [Illustration: 172.--STAIRCASE AT LYVEDEN OLD BUILDING, NORTHAMPTONSHIRE.] [Illustration: PLATE LXXII. STAIRCASE FROM BURGHLEY HOUSE, NORTHAMPTONSHIRE.] [Illustration: 173.--DETAILS OF STAIRCASE, HAMBLETON OLD HALL, RUTLAND.] [Illustration: 174.--STAIRCASE FROM EAST QUANTOCKSHEAD, SOMERSET.] [Illustration: 175.--DETAILS OF STAIRCASE, LYVEDEN OLD BUILDING, NORTHAMPTONSHIRE.] [Illustration: PLATE LXXIII. PLANS OF STAIRCASES FROM JOHN THORPE'S DRAWINGS IN THE SOANE MUSEUM.] [Illustration: 176.--PIERCED BALUSTER.] [Illustration: 177.--STAIRCASE AT OCKWELLS MANOR HOUSE, BERKSHIRE.] The principle upon which these wood staircases were constructed may be compared to that of the ladder, where the sides of the ladder are replaced by deep and comparatively narrow pieces of wood called "strings," and the rungs are replaced by the treads and risers. One side of this amplified ladder was placed hard on to the wall, the foot of the other was secured into a stout upright post, or "newel," as also was the top: into the same newel that received the top of the first string the foot of the second was secured at right angles, and so onwards and upwards as far as the staircase extended. At about two feet above the top of the string, and parallel to it, was the handrail, and between the handrail and the string were fixed the balusters. The top of the first flight leant against a flat landing, on which also the foot of the next flight rested. The construction, therefore, was extremely simple in principle, far simpler than that of the continuous winding flights of the eighteenth century; but the component parts were often highly decorated. All the woodwork was of fairly large dimensions; the newels were six, seven, or eight inches square, the handrail was generally nearly as wide as the newel, the strings were three inches thick or even more, the balusters were proportionately massive. The flights were five or six feet wide, and comprised usually about six steps, although they were longer when necessity demanded it. The plans on Plate LXXIII. show various arrangements of staircases taken from John Thorpe's collection of plans in the Soane Museum. Nos. 1 and 2 are the most usual types, and of these No. 1 is the more frequent. The space to be occupied by the stairs is divided into nine equal squares, of which those in the corners represent the landings, while the intermediate ones are occupied by the steps; the middle square is the "well-hole." The staircase at Lyveden Old Building, in