The spectres may be easily made to appear life-sized or colossal, by having the plate nearer the eyes while receiving the impression, and by increasing the distance between the observer and the surface against which they are seen. As a general rule, the observer should be about eight to twenty feet from the surface. When the spectres are seen against opposite houses, the sky, and other distant surfaces, they will appear colossal.
Should any one not be able to see the spectre’s features, the reason will be, either that the eyes have been allowed to wander, or the head to move, while looking at the plate.
Many persons will see some one coloured spectre better than the others, in consequence of their eyes not being equally sensitive to all colours.
The colours in the plate will be found to reverse themselves in the spectres, as explained elsewhere, the spectres always appearing of the complementary colour to that of the plate from which it is obtained. Thus, blue will appear orange, and orange blue, &c.
LIST OF THE PLATES.
This winged figure of Victory will give a white spectre by artificial light (rather green by daylight), the red wreaths green, the green roses red, and the orange stars blue.
This black figure will give a white spectre.