A third example is given in Figure 1.15(c). This pattern of black and white shapes is simply one of melting snow on a grass surface. But it also has a human interpretation: a late medieval representation of Jesus Christ. To see this you have to look very carefully. The upper margin of the picture cuts the brow, thus the top of the head is not shown. The point of the jaw, brightly illuminated, is just above the geometric centre of the picture . A white mantle covers the right shoulder with the right upper sleeve exposed as the rather black area at the lower left. The hair and beard are after the manner of a late medieval representation of the face of Christ. Once that face has been seen, then we live with for life. I find it impossible to 'unsee' that pattern (once i have seen it) and thus may miss other and equally arguable interpretations.
the examples given in these figures will be familiar to many readers. But we often fail to appreciate how much the lessons they teach have implications for geographic observation. Consider the three maps in Figure 1.16. The upper diagram (a) show a small 12*16 metre (40*52 feet) section of Salisbury Plain in southern England, with the blackened areas representing depressions in the old soil surface of this chalk downland (see the discussion in Box 22.B). The field archaeologists interpret these depression as the remnants of post holes dug to support the main timbers of a hut.