old trick

My Introduction to magic was the amateur magicians handbook by Henry Hay at a young age on a recent trip to powells book store in portland oregon they had a original copy. I studied sleight of hand for about 12 yrs, but lost touch as an adult with this passion of mine. I bought this book with...

I see a lot of laymen and kids who know just one magic trick, and it's usually this one, which I'd categorize under "mathemagic": Deal 21 cards face up in 3 rows of 7. Ask the spectator to think of any of the 21 cards. Turn over the 3 rows into face-down piles. Ask the spectator which pile...