Blutac.....when you aren't watching
why are coalholes round?
1.it fits any way round
2. it can't fall through hole
3. easy to roll it aside
4. uses minimal material
the heart shaped wood c.1814
(this is real)
how to draw a straight line
Used in the air pumps in world's first airconditioned building, the Houses of Parliament, London
The Peaucellier cell 1864
town and country
Sierpinski carpet - Cesaro Sweep
how to draw a spiral
picture shows stairs in the Monument, London
super ellipse
|x|n + |y|n = 1
n = 2 gives a circle, becomes square as n increases
shown above n=3.5 & n=2.5
Piet Hein
Kepler's drawings of decorated polyhedra.
