Tom blok Photo collection by Th.Schiöler Spiral scoops, screws and the chain pump The "liberation" pump in China Photo 157
The "liberation" pump in China
Gul streg
Photo 511 x 506 pixels, 43,6 K
 
The "liberation" pump used in Thailand
The "liberation" pump was constructed in 1947, but the invention is much older. See [161].
[157]