Hollow Post Mills
Wooden hollow-post windmills were used for lifting water and irrigation. One of the early hollow-post windmills in South Africa was built by J.C. Poortermans in 1848 at the home of a Mr. Brink at Saldanha Bay. (Not the illustration on the left).
It consisted of a vertical hollow post which was supported by sloping ladders against two opposite sides and a sloping metal strut against each of the other sides. The head of the post carried four latticed sails which, by means of a cranked shaft, lifted and lowered a long steel rod passing down the hollow post to the pump or other lifting mechanism below.