For the Merchant, I would observe a straight line DAE, with the midpoint (A) being very bright due to its proximity. However, the line would quickly fade into dimness on either side, as the sides AC and AB recede rapidly into the fog. Consequently, the Merchant's extremities, D and E, would appear very dim.

In contrast, for the Physician, I would also see a line (D'A'E') with a bright center (A'). However, this line would fade into dimness less rapidly, as the sides (A'C', A'B') recede less quickly into the fog. Therefore, the Physician's extremities, D' and E', would appear less dim than the Merchant's.

From these examples, the Reader can understand how, after extensive training and practical experience, the well-educated classes among us can distinguish between the middle and lower classes through visual discrimination. If my Spaceland Patrons have grasped this general idea, I will have achieved my goal. If they find my account credible, I will have succeeded. For clarity, I should avoid detailing further, as this might confuse them. However, for the benefit of the young and inexperienced, who might conclude from the two simple examples that visual recognition is straightforward, it is important to note that real-world recognition problems are much more complex and subtle.
