The recent post about Bill Franklin's Flettner Rotor Ship demonstration
reminds me of a note I published in The Physics Teacher about twenty five years
ago called "A Forgotten Magnus Effect Demonstration". This was a cart mounted
on four HO-scale model railroad bogies, running on two sets of parallel tracks
for stability. A small DC motor was mounted on top of the cart with its shaft
vertical, and the spinning drum was a small spaghetti-sauce can. The power
supply was via two thin and flexible wires. I used a box fan to supply the air,
and the cart would go forward and backward depending on the direction of
rotation of the can.
Over the years I have accumulated all sorts of material on the Flettner
rotor ship, including a photocopy of Anton Flettner's book, "The Story of the
Rotor" and a nice stero card of one of his ships, but have never found the time
to write a note about it. In my old age I probably ought to build a model
Flettner sailing yacht, but I have stacks of things to do and write before I
get to it.