Fig. 63.
In Fig. 63 the two statues A and B are the same size. So if traced through a vertical sheet of glass, K, as at c and d, they would also be equal; but as the angle b at which the upper one is seen is smaller than angle a, at which the lower figure or statue is seen, it will appear smaller to the spectator (S) both in reality and in the picture.
Fig. 64.
But if we wish them to appear the same size to the spectator who is viewing them from below, we must make the angles a and b (Fig. 64), at which they are viewed, both equal. Then draw lines through equal arcs, as at c and d, till they cut the vertical NO (representing the side of the building where the figures are to be placed). We shall then obtain the exact size of the figure at that height, which will make it look the same size as the lower one, N. The same rule applies to the picture K, when it is of large proportions. As an example in painting, take Michelangelo’s large altar-piece in the Sistine Chapel, ‘The Last Judgement’; here the figures forming the upper group, with our Lord in judgement surrounded by saints, are about four times the size, that is, about twice the height, of those at the lower part of the fresco. The
figures on the ceiling of the same chapel are studied not only according to their height from the pavement, which is 60 ft., but to suit the arched form of it. For instance, the head of the figure of Jonah at the end over the altar is thrown back in the design, but owing to the curvature in the architecture is actually more forward than the feet. Then again, the prophets and sybils seated round the ceiling, which are perhaps the grandest figures in the whole range of art, would be 18 ft. high if they stood up; these, too, are not on a flat surface, so that it required great knowledge to give them their right effect.