Model of a Half-Twist Surface by Alexander Crum Brown, c 1900.
One half of a model of a half twist surface
Model of a half twist surface
Model of a half-twist surface. Alexander Crum Brown (1838-1922), who was professor of mathematics at Edinburgh, was a prolific maker of mathematical models. This one is related to the Klein bottle and Mobius strip.
One half of a model of a half twist surface
One half of a model of a half twist surface