But it isn’t. It is in fact a mathematical investigation into tiling the plane with tiles of fivefold symmetry. See the full article by Craig Kaplan at Plus Magazine for a nice in depth discussion of the problem.

The Trouble With Five

Certainly I never see anything in London that resembles it in public spaces – we get stuck with very ordinary tiling patterns on the whole – but this morning I spotted an interesting manhole cover, with a pattern not unlike the central stars of many a zelij pattern:

Borough High St, London, SE1

I don’t think the Moroccans would stick a rather awkward square in the middle though…

Excitingly you can even see it on Google Street View:

Could do it better if I was using a ruler and not half watching the Apprentice.

The point is – if you are at all interested in the construction and art of zelij, you have to have this book:

Arabesques: Decorative Art in Morocco, by Jean-Marie Castera.

It’s a quite pricey, but worth every single penny.

http://www.cgl.uwaterloo.ca/~csk/washington/tile/islam/

I have to say, despite the knowledgeable sounding intro, the patterns generated are not very authentic (at least I couldn’t get anything to look very authentic)

The failing seems to be in the construction of the patterns – I have a book which describes a much better system which if implemented would generate much better patterns (but would this be a bit of a soulless process? Part of the attraction is the effort required and the artistry of the original craftsmen)

It’s not exactly Zelij related, but without a good understanding of mathematics and geometry, the art of Zelij would be well nigh impossible, and these documentaries explore how such knowledge was acquired and discovered at this early period.

It can be watched online at this url, at least for the next month or so, but probably only if you are based in the UK:

http://www.bbc.co.uk/programmes/b00gksx4

Lunar eclipse

A nice example of Islamic astronomy showing different phases of the moon by a scholar called al-Bīrūnī who lived in the 10th century in what is now Afghanistan.

Column with repeating 8-point star
Am especially impressed with the way the column face is exactly the right width for the design.

Three interwoven 8-point stars in the ‘wicker-work’ style

16 point star
Slightly more elaborate…

64-point star ceiling
Normally the centre star in designs have 8 points; 16 if the designer was in an extravagant mood (see above). However one particular palace had many 32 and 64 point stars. Complexity nearly to the point of absurdity, and actually not as aesthetically pleasing as the simpler designs, in my humble opinion.

Here are some websites that discuss this.

Detailed discussion of computer generated Zelij patterns:
http://www.mi.sanu.ac.yu/vismath/kaplan/index.html

The basic table of symmetries:
http://www2.spsu.edu/math/tile/symm/ident17.htm

From the same website – an example of a pattern from the Al Hambra with p6m symmetry:
http://www2.spsu.edu/math/tile/grammar/moor/moor3f.htm

The Wikipedia page on rotational symmetry
http://en.wikipedia.org/wiki/Symmetry_combinations

82 Zelij pics on Flickr. I must add mine…
http://www.flickr.com/photos/tags/zelij/interesting/

Dutch artist MC Escher was a master of tiling symmetries
Douglas Hofstadter, ‘Visions of Symmetry’

Tile Generator (design your own replicating tile structure):
http://escher.epfl.ch/escher/

Dr Heinrich Heesch identified 28 types of repeating structure
http://www.eschertile.com/tile28.htm