name, for the first time in any of the tests, it crossed the second dividing line at the first impulse; moved toward the third and stayed there.
Even Siler now waited with bated breath, as Trant took up his pile of pictures; and, as he came to the picture of the murdered man and the house where he had lived, for the second and third time in that single test the light—stationary when Sin Chung Ming glanced at the other photographs—trembled across the screen to the third dividing line. For the others it had moved hardly eighteen inches, but when Sin Chung Ming saw the pictured face of the murdered man it had swung almost three feet.
"Inspector Walker," Trant drew the giant officer aside, "this is the man, I think, for the final test. You will carry it out as I arranged with you?"
"Sin Chung Ming," the psychologist turned back to the Chinaman swiftly, as the inspector, without comment, left the room, "you have been watching the little light, have you not? You saw it move? It moved when you lied, Sin Chung Ming! It will always move when you lie. It moved when you said you did not know Walter Newberry; it moved when you saw his picture, and pretended not to know it; it moved when you saw the picture of his house, which you said you did not know! Look how it is moving now, as you grow afraid that you have betrayed your secret to us now, Sin Chung Ming—as you have and will," Trant pointed to the swinging light in triumph.
A low knock sounded on the door; but Trant, watching the light now slowly returning to its normal place, waited an instant more. Then he himself
