Bank Underground Station, London, is built on a curve, leaving a potentially dangerous gap between platform and carriage to trap the unwary. The loudspeaker voice instructs passengers to Mind the gap: the boundary between train and platform.

Shraffage is halfe a riall per every thousand rialls.

Among the hills are basin-like valleys, round, or irregular in form, and without outlet, which are sometimes dry but generally hold swamps or small lakes, which have frequently been filled in with material washed from the hills so as to become flatbottomed.

A transition from an ovoidal to a spherical shape by increasing the generation number has been predicted for dendrimers (8 ).