“May it please the Court, I am ready for the experiment,” he said.

“The witness will proceed,” said the judge.

“There will soon appear upon the wall, above the heads of the Jury,” said Prof.  Timms, “the genuine signature of Nicholas Johnson, as it has been photographed from the autograph letter.  I wish the Judge and Jury to notice two things in this signature—­the cleanly-cut edges of the letters, and the two lines of indentation produced by the two prongs of the pen, in its down-stroke.  They will also notice that, in the up-stroke of the pen, there is no evidence of indentation whatever.  At the point where the up-stroke begins, and the down-stroke ends, the lines of indentation will come together and cease.”

As he spoke the last word, the name swept through the darkness over an unseen track, and appeared upon the wall, within a halo of amber light.  All eyes saw it, and all found the characteristics that had been predicted.  The professor said not a word.  There was not a whisper in the room.  When a long minute had passed, the light was shut off.

“Now,” said the professor, “I will show you in the same place, the name of Nicholas Johnson, as it has been photographed from the signatures to the assignment.  What I wish you to notice particularly in this signature is, first, the rough and irregular edges of the lines which constitute the letters.  They will be so much magnified as to present very much the appearance of a Virginia fence.  Second, another peculiarity which ought to be shown in the experiment—­one which has a decided bearing upon the character of the signature.  If the light continues strong, you will be able to detect it.  The lines of indentation made by the two prongs of the pen will be evident, as in the real signature.  I shall be disappointed if there do not also appear a third line, formed by the pencil which originally traced the letters, and this line will not only accompany, in an irregular way, crossing from side to side, the two indentations of the down-strokes of the pen, but it will accompany irregularly the hair-lines.  I speak of this latter peculiarity with some doubt, as the instrument I use is not the best which science now has at its command for this purpose, though competent under perfect conditions.”

He paused, and then the forged signatures appeared upon the wall.  There was a universal burst of admiration, and then all grew still—­as if those who had given way to their feelings were suddenly stricken with the consciousness that they were witnessing a drama in which divine forces were playing a part.  There were the ragged, jagged edges of the letters; there was the supplementary line, traceable in every part of them.  There was man’s lie—­revealed, defined, convicted by God’s truth!