To my surprise, not many people outside of Zimbabwe know about the Blair Toilet. This revolutionary design for a long-drop toilet was developed at the Blair Research Institute for mass deployment in the rural areas of Zimbabwe, where diseases such as cholera and typhoid were rife. The toilet is easy to construct, but its design makes it very clean, hygienic, and free of flies. It is described here as "[using] little or no flush system, [being] odorless, free of insects, and [doubling] as a bathroom." There is a description of the mechanism here, but the basic idea is that the pit underneath the toilet has a chimney or vent - warm air rises out of this chimney, taking the smells and flies with it. There is also a sort of valve system created by the doorway and the positioning of the vent which means that flies always attempt to fly the wrong way, trapping themselves further.
The pure genius of the system inspired a doctor friend of mine to write the following:
Ode to the Blair Toilet (or: Privy Paean)
By Charl Oettle, 1982
You may sit upon this privy
Looking neat and clean and spivvy
And may wonder where the flies and odours went
Yes, the whole place smells of jasmine
And each fly is now a has-been
They've been flummoxed by the privy with the vent.
In the old days every toilet
(Though one tried so hard to foil it)
Smelled and reeked and ponged enough to make one faint,
And the flies bred out in dozens
With their uncles, aunts and cousins
And to use such privies one need be a saint.
Any other lesser mortal
As he staggered through the portal
Would break out in language loud and short and strong,
And to atavistic howls
He'd evacuate his bowels
Swatting flies and holding noses in the pong.
But these troubles now are ended
As the privy has been vented
And it's looking rather good and clean and fresh (tra la la);
In the sun the vent gets hotter,
And it sucks out quite a lotter
Smells and flies that bump their heads against the mesh.
Having flown so quick and nimbly
Up the hot and foetid chimbly
Now their brains and hopes are dashed and will is spent,
And they die, now ten, now twenty,
In their cesspit horn of plenty -
Vindication for the privy with the vent!