Perspective practical, or, A plain and easie method of true and lively representing all things to the eye at a distance by the exact rules of art ... / by a religious person of the Society of Jesus ... ; faithfully translated out of French, and illustrated with 150 copper cuts ; set forth in English by Robert Pricke ...

For the winding stairs, or turning Ascent.

THIS Figure is the same with that before-going, which I have not shadowed, on purpose to make the Order to be the bet∣ter understood. And for this reason I have reserved for this, the Tree, or the Nuell of the Ascent, which one may finde by making at the center A, a Round in Perspective, or rather a demi-round, seeing that we can see but the half as is B C, at which demi-circle we must draw lines to the Center A, from all the divisions of the square of the first Plane, which will give G E F G H I K, which will divide this Arch B C into eight parts. And from the section O we must raise Perpen∣dicules, and observe that they shall divide justly at the point, where we must place the steps or degrees, which we shall have made: as for ex∣ample, the step I, shall be divided by the Perpendicule elevated from its point upon the demi-round, as we see in A: the other step after which is the second, shall be divided by the Perpendicular of the point, which K shall have made at the demi-round; and so of all the others.

The rest which is in the figure, as the doors and the windows, shall be made according to the foregoing Orders.

[illustration]