library, and the furniture, including the table at which we sat, was of the ordinary make and style, with none of the intricacies so necessary to the every-day conjurer; and I am convinced that the furniture of the room and its general surroundings played no part whatever in the accomplishment of the facts which I am going to narrate.
Having produced a small book-slate, Mr. Davey asked me to examine it, and to satisfy myself as to its simplicity of construction, etc. I did so; the slate was composed of two ordinary pieces of slate, about six by four inches, mounted in ebony covers hinged on one side with two strong plated hinges, and closed in front, beyond the question of a doubt, with a Chatwood's patent lock.
With the exception of a small escutcheon, bearing the initials of the donor, the slate was plain and substantial, and bore the strictest inspection, so as to entirely preclude the idea of chemicals or any other similar agent being used to it.
(a) After I had finished examining the slate, Mr. Davey asked me to write in the slate any question I liked while he was absent from the room. Picking up a piece of grey crayon, I wrote the following question: "What is the specific gravity of platinum?" and then having locked the slate and retained the key, I placed the former on the table and the latter in my pocket.
After the lapse of a few minutes I heard a distinct sound as of writing, and on being requested to unlock the slate I there discovered to my great surprise the answer of my question: "We don't know the specific gravity, Joey." The pencil with which it was written was a little piece which we had enclosed, and which would just rattle between the sides of the folded slate.
Having had my hands on the slate above the table, I can certify that the slate was not touched or tampered with during the time the writing was going on.
(b) Next; having taken an ordinary scholar's slate and placed a fragment of red crayon upon it, Mr. Davey placed it under the flap of the table. I held one side with my hand as