Snow in the Desert

Image

source: NASA Earth Observatory

via [NASA Earth Observatory]

Advertisements

[Image] Archimedes’ screw

Image

[Image] Archimedes' screw

In the Netherlands, some of the windmills used to drain the polders at Kinderdijk have been replaced by modern Archimedes screws.

Image by: M.A. Wijngaarden
License: CC Attribution-Share Alike 2.5 Generic license.