[ CLXVII]
Reflection in a Looking-glass
| Fig. 294. |
I had noticed that some of the figures in Titian’s pictures were only half life-size, and yet they looked natural; and one day, thinking I would trace myself in an upright mirror, I stood at arm’s length from it and with a brush and Chinese white, I made a rough outline of my face and figure, and when I measured it I found that my drawing was exactly half as long and half as wide as nature. I went closer to the glass, but the same outline fitted me. Then I retreated several paces, and still the same outline surrounded me. Although a little surprising at first, the reason is obvious. The image in the glass retreats or advances exactly in the same measure as the spectator.
Suppose him to represent one end of a parallelogram e·s·, and his image a·b· to represent the other. The mirror AB is a perpendicular half-way between them, the diagonal e·b· is the visual ray
passing from the eye of the spectator to the foot of his image, and is the diagonal of a rectangle, therefore it cuts AB in the centre o, and AO represents a·b· to the spectator. This is an experiment that any one may try for himself. Perhaps the above fact may have something to do with the remarks I made about Titian at the beginning of this chapter.
Fig. 295.