I had almost decided to drop Mrs. Patterson and her slate writing, although reluctant to do so, because I had no certain and positive evidence of fraud with which to confront my friend, who was getting impatient at my slowness in accepting all I had seen, when I resolved to push my investigations to a point of certainty, one way or another, and hit upon the little scheme of going prepared, at my next visit to Mrs. Patterson, with a mirror in my pocket which I could hold under the table at an angle that would reflect whatever occurred on the other side of the table, in the Medium's lap, the accustomed position of the mysterious slate. The sitting was held in broad daylight, and the table was so placed that the Medium was seated with her back to a window, affording sufficient light for the experiment. I purposely avoided removing my overcoat on this day, because I wished to hide my movements as much as possible, and sat down at my side of the table with considerable misgiving as to the result of taking liberties with the Spirits. The Medium this time had on her table a new slate, a larger one, one which she said had belonged to the celebrated Slade who had himself received messages on it. She said her old slate was broken, which was probably true; when I had last seen it it was in a battered condition. She asked if it would make any difference to me if she used the new slate. The only apparent difference between the slates was that this one was larger and did not close with a screw, therefore, thought I, more easily manipulated; consequently I did not withhold my consent. I wrote upon a slip of paper my question, "Will Dr. H. advise me what to do for Juliet (an old colored patient)?" I folded over the slip of paper five times, put it in the slate with a small stub of pencil, and down the slates went into the lap of the Medium where I could see them, lying plainly reflected in my little mirror which I had slipped out of my pocket and laid across my knees at the proper angle of reflection.