Sky ships are a major means of transportation on Worldtree. They are tricky enough, and the whimsical weather of the Worldtree’s air, pushed around by air deity’s servants, not all of which are serious or patient, makes the travel by sky ship a little risky — but it still is safer than the long and very dangerous travel through the Verticals, the murky and monster-inhabited tangle of boughs that makes up the Tree’s trunk. The sky ships made communication between different bough-realms of the Tree much easier, and the same is true about colonisation… they, as well as bound spells, were probably the major factors in the local Renaissance.

2000
Graphite pencil

Review enlarged detail of this picture here