Instructions by Peter Warlock for this very special slate which first reveals the total of several lines of figures giving one number at a time and then a kicker addition which makes for a climax finish to the effect.
After three spectators have written random numbers and these totaled by a fourth spectator the total is written in a vertical row on the slate. Next to this row are four cards clipped on one edge covering half of the slate. A spectator is asked to name any of the visible numbers and immediately a square is drawn around that number. All of the cards are removed one by one showing the prediction to be correct with the last number that has the square around it revealed and the number under the card matches and has a square around it as well!
From 1978 and a knock-out of an effect. Includes 4 pages of illustrated instructions. Includes nice sleeve over cover. Condition very fine.