Previous research had shown that people exhibiting personality traits like sensation-seeking are more likely to become entrepreneurs than their less outgoing and more level-headed peers.

To measure this, passengers were given glasses of water with seven different concentrations of colorless artificial flavorings, and asked to note at which level they registered a sensation.

From the gallery the view extends across the garden to the canopy of trees in the park, thus negating the sensation that one is below street level.