Henry Ernest Dudeney/Puzzles and Curious Problems/363 - At the Mountain Top/Solution

Puzzles and Curious Problems by Henry Ernest Dudeney: $363$

At the Mountain Top

"When I was in Italy I was taken to the top of a mountain

and shown that a mug would hold less liquor at the top of the mountain than in the valley beneath.

Can you tell me," asked Professor Rackbrane, "what mountain this might be that has so strange a property?"

Solution

The surface of water, or other liquid, is always spherical, and the greater the sphere is the less is its convexity.

The spherical surface of the water must, therefore, be less above the brim of the vessel

and consequently it will hold less at the top of a mountain than at the bottom.

This applies to any mountain whatsoever.

Sources

• 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Solutions: $363$. -- At the Mountain Top
• 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Answers: $534$. At the Mountain Top