It's not just the height, it's the Humboldt current: cold water from the Antartic towards the equator, which creates an inversion layer, so no rain from the Pacific while the Andes block anything from the east. The most extreme result is the Atacama Desert, on the edge of which Jérôme's journey started. I'm surprised it appears so little-known here: when I went to school, both in Hungary and West Germany, it was brought as an example of climatic complexities. Also, being one of the driest places on Earth, it is also ideal for astronomy, and all three sites of the European Southern Observatory are located in the Chilean part of the desert.

_{*Lunatic*, n.
One whose delusions are out of fashion.}