Let us look from a short distance at Figure 1. What do we see? From the black background the picture of a gray, wrinkled surface stands out. Some places look like rough folds, others like densely arranged warts, one place reminds us of the waves of a muddy liquid, others of clouds of smoke (perhaps because the picture in this border place is out of focus). We find a place which looks like a frizzly fur, yet this is no fur, for there are no hairs to be seen. Now what is it? Is it the skin of a toad under a magnifying glass or perhaps a part of the culture of the celebrated fungus to which we are indebted for penicillin? Or perhaps a close-up of the neck of an old mountaineer? No, this is a perfect photograph of a cloud of the type known to meteorologists as cirro-cumulus. Let us now look again at this figure, but from afar. Once we know what it is and in what way one should look at it, we see immediately the enormous depth of the sky, and a large fluffy cloud whose variable structure, while unimportant in the details of limited places, in its entirety reminds us of a sheep's fur.