Rulers by Père Alex

A classic illusion, made famous by psychologist Joseph Jastrow, is elegantly reinterpreted here by Père Alex. Two wooden school rulers – one marked in centimeters, the other in inches – provide a distinctive visual punchline. The magician explains that the imperial system seems exceptionally mysterious to a Frenchman – and proves it instantly: when placed side-by-side, 15 cm and 6 inches appear to be identical. By simply swapping the positions of the rulers, not only does the apparent size change, but 7 inches then seem to correspond to 9 cm. Finally, Père Alex reveals that the two rulers are actually exactly the same length. A strong, clear, and immediate visual deception that always elicits wonder and a smile.

Contents

• A beautiful wooden box, specially made for this effect.
• Two wooden rulers: one marked in centimeters, one marked in inches.
• An explanatory video in French, in which Père Alex explains the principle of the trick.

Why this set is convincing

• Direct, instantly recognizable illusion: Spectators see an apparent system change before the true principle is revealed.
• Robust wooden construction and a specially made storage box – ideal for transport, stage, or studio use.
• Practical learning aid: The accompanying explanatory video makes understanding the trick accessible – especially for aspiring magicians who want to master timing and presentation.

Possible uses

• Stage performance or variety show: a standalone, impressive effect that captivates both audience and jury.
• Close-up magic: compact, portable, and immediately effective for small groups.
• Didactic use: clear demonstration of units of measurement and perception – including a French explanatory video for multilingual performances.