The Elements of Perspective / arranged for the use of schools and intended to be read in connection with the first three books of Euclid

by John Ruskin

Fig. 61.

We may now proceed to an architectural example.

Let A H, [Fig. 60.], be the vertical profile of the capital of a pillar, A B the semi-diameter of its head or abacus, and F D the semi-diameter of its shaft.

Let the shaft be circular, and the abacus square, down to the level E.

Join B D, E F, and produce them to meet in G.

Therefore E C G is the semi-profile of a reversed pyramid containing the capital.

[p83]
]Construct this pyramid, with the square of the abacus, in the required perspective, as in [Fig. 61.]; making A E equal to A E in [Fig. 60.], and A K, the side of the square, equal to twice A B in [Fig. 60.] Make E G equal to C G, and E D equal to C D. Draw D F to the vanishing-point of the diagonal D V (the figure is too small to include this vanishing-point), and F is the level of the point F in [Fig. 60.], on the side of the pyramid.

Draw F

m

, F