Standing at the northeast extremity of the yard, round the pillars of the Janus Gate, were several men who did not weep, wail, or proffer coin-purses. They only stood, backs to the gate, facing the flow of prisoners, and watched. It was a wonder to see them. From their postures you might identify them from a distance as mere idlers. But as I approached—following Mr. Kikin—I noted that these men wore curious expressions on their phizzes: each was as intent as a cat in the instant before it pounces upon an unsuspecting bird. These men were not idling, but working, practicing their profession with as full attention as the late Mr. Hooke when he would peer through his microscope at a swarm of animalcules. Some of the prisoners passing through the Janus Gate were oblivious; their faces were scanned and committed to memory. Others, wiser in the ways of the flash world, recognized these loiterers as thief-takers, and hid their faces behind their sleeves, or even walked backwards until they had passed safely through the gate. Some of the thief-takers stooped to childish but effective tricks, as calling out names: "John! Bob! Tom!" which made certain prisoners turn their way, the better for their faces to be inspected and their moles, scars, missing teeth, &c., to be memorized.