On the surface - The Visualization of Spatial Social Structure - page 213

1989 County Council Elections:

Surface based on the
three party triangle,
height proportional to
numbers of votes.

English Voting Composition Surface.

Labour Conservative

Democrat

Labour Conservative

Figure 7.10 By 1989 the highest peak had, remarkably, moved into the Liberal
(Democrat) territory, just over the Conservative border. Other high points were
in the centre of the Conservative and Labour territories and, in general, there had
been a move away from the centre of the triangle. Places had been sorted out on
to a line that curved from Labour to Conservative to Liberal strongholds.