This is probably the kind of trough that's meant: http://en.wikipedia.org/wiki/Watering_trough http://en.wikipedia.org/wiki/Watering_trough, detailed image: htt

This is probably the kind of trough that's meant: http://en.wikipedia.org/wiki/Watering_trough http://en.wikipedia.org/wiki/Watering_trough, detailed image: http://en.wikipedia.org/wiki/Watering_trough#/media/File:Cattle_trough.jpg http://en.wikipedia.org/wiki/Watering_trough#/media/File:Cat.... If you "think away" the actual trough and keep only the liquid, you get the cuboid that the text is referring to.