Zufall, Bernard: Zufall's Memory Trix No. 2 Mental File Index ©1940 Bernard Zufall, NY Softcover, saddle-stitched, 5.5x8.5", 9 pages

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Comments: Feats of memorization. Zufall published a series of 6 volumes in the Memory Trix series, including:
No. 1 Magazine Memorizing
No. 2 Mental File Index
No. 3 Calendar Memorizing
No. 4 Memorizing a Deck of Playing Cards
No. 5 Memorizing Numbers
No. 6 Memorizing Facts and Figures

Contents (from LearndedPig eBook edition):

1 Effect: While blindfolded, performer is able to repeat back 20-30 words provided by the audience
1 Props: Blackboard, Blindfold
1 Preparation
2 Code Words
3 Procedure
4 Sample Session
4 Preparing Code Lists
5 The Alphabet Trick
6 Presidents and Vice-Presidents of the United States
6 Remembering the Hundred Largest Cities of the United States
6 American States and Capitals
7 Mental Memos For Daily Tasks
7 Miscellaneous Memorizing
8 Appendices: other approaches
10 Special Note