Spaceland had started several generations back with a flat plate of asteroid rock half a mile in diameter. A mad health cultist had raised a transparent hemisphere of Air-Gel on the plate, installed an atmosphere generator, and started a colony. From that, Spaceland had grown into an irregular table in space, extending hundreds of miles. Each new entrepreneur had simply tacked another mile or so onto the shelf, raised his own transparent hemisphere, and gone into business. By the time engineers got around to advising Spaceland that the spherical form was more efficient and economical, it was too late to change. The table just went on proliferating.