Used materials are pencil, indian ink, Letraset Promarker, Letraset Flexmarker on Canson 180 gr/sqm (85 lbs/sqm) drawing paper.
The inspiration for this quick sketch comes from a model planetarium in the Teylers Museum (Haarlem, NL) (http://www.teylersmuseum.eu/teylersuniversum/index.php?m=instr&lang=nl – it’s Flash, so not visible on iPad) that I recreated in modo for a project in 2010. I thought I lost the file, but found it again and decided to texture it anew (time-pressure at the time didn’t allow for much more attention to detail) and also to rig it and render an animation for my new website in the making. But lacking the time right now I just decided to include it in a quick cartoon.
The planetarium in the Teylers museum is built by the famous Fleet Street instrument-maker George Adams jr. in 1790. Exactly the same model in its original box can be admired in the Groningen University Museum. There, all the parts are still unmounted, so the mechanism can be studied in detail.
The sketch doesn’t show the planetarium in its right dimensions, nor is it very accurate, it’s just a simple fantasy.