Thayer Super Miracle Slate circa 1940’s

A great prediction effect from Thayer.  The magician shows a large slate and writes on one side of it his prediction which he covers with a cloth attached to the slate. He has four audience members select numbers and writes them on the slate (no force of any kind).  He (or a member of the audience ) totals the numbers. The magician turns the slate around and lifts the cloth to reveal his exact prediction!  With a coy of original instructions. Very good condition. Slate does not appear t have been used.

Estimate $200-300