When two slates only are used, the prepared slate is usually lying on the table when the sitters take their seats.  No attention is called to it, and some little time is taken in conversation, and in the spasmodic jerking caused by ‘electric currents’; in a few minutes the slate pencil is placed on the slate; no offer is made of showing both sides, which would be quite needless, since the side which is exposed is perfectly clean, and it is on that side which the Spirits are expected to write; the slate is kept almost constantly and wholly in full view and but very slightly inserted beneath the table.  After an interval of waiting, during which, by constantly looking at the slate as though impatient for the writing to begin, whereby his sitters become accustomed to the appearance and disappearance of the slate, the Medium reaches for a second slate, ostentatiously washes both sides, lays it on the table, removes the pencil from the first slate to the second, and places over it the first slate with its prepared message, face downward, and the trick is done.  The two slates are held for a minute under the table, and are then held to the ear or on the shoulder of the sitter on the Medium’s right hand—­never to any other sitter, since to do so would reveal the scratching of the Medium’s finger-nail on the rim of the slate, whereby the writing of the pencil within the slates is counterfeited.  I have distinctly, three or four times, watched the motion of the Medium’s finger while thus scratching; as I sat facing the window the fingers which held the slate and made the fictitious writing were sharply outlined against the light.  And here let me say that he who sits on the Medium’s left hand, the side to which he turns almost his full back, has the best position for observation.  He told me many times that he did not like to have three sitters, but much preferred only two; at the third side, when unoccupied, wonderful manifestations occur, such as a chair’s elevation, or being thrown down, or the appearance of the unsupported slate, etc.  These manifestations are executed by the Medium’s foot, and lest its motions under the table should be detected, the longitudinal cracks where the two table-leaves join, were carefully stuffed with paper, although, to be sure, he once explained to me the presence of this paper as necessary to keep ’the electricity from flowing through.’

Although Dr. Slade had agreed verbally in New York that the last seance of the series should be in the presence of all the Commission, he flatly refused, when in Philadelphia, to hold any in the presence of more than three at a time.

On one occasion, when the Medium was very sure of his sitters, he placed the prepared slate, face downwards, on the table, with his fingers resting on the upper surface, then in a few minutes the slate was lifted up and the writing displayed, as though just made by Spiritual agency.  Generally, however, when the writing is thus exhibited, it is in answer to a spoken question, and the reply is written by the Medium in his lap and the slate turned over before it is placed on the table.  Manifestly it cannot occur as an answer to a written question, unless the written question is exposed on the upper side of the slate.