REPORT OF MR. NELSON L. DERBY.
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six feet, its thickness six inches,* and its composition Kuf- steiner cement and sand.
I lived on one occasion for several months in a new house in Vienna, where a stairway of the form referred to exists.
I®
Section of same, showing one story.
It is remarkably easy of ascent, and has plenty of light and air, provided by windows opening onto a large court. It is inclosed, with passage, by four walls, bounding a rectangle of eighteen feet in width by twenty-two feet in depth; on three sides of this, three flights of steps, each six feet in width, are supported at one end only ; on the fourth side is a vaulted passage of the same width, running across from wall to wall, and communicating with three dwellings. In each of the two opposite corners are resting-places, six feet square, and in the centre of the whole is an open space measuring six feet by ten feet. The breadth of each step is thirteen inches, and its height six inches. By law, these dimensions cannot be less in the first case than eleven inches, nor more in the second than six inches. In the case of spiral stairways, or those ascending in any curve, the breadth of the steps at the distance of eighteen inches from the walls must be at least eleven
o
inches, and at the smaller end at least five inches. All these stairways are provided with a metallic or stone railing. If