The changing distribution of voting composition in Britain, 1955-87 (Colour).

Arrows, coloured by the mix of votes in each election, pointing in the direction of movement on the electoral triangle from the previous election, with length in proportion to the magnitude of the swing, are drawn in the 705 consistent parliamentary constituencies on the equal electorate cartograms (Appendix C) software by author on an Archimedes computer.

The first frame shows the distribution of votes in 1955 from which these swings have occurred. The seats of Northern Ireland can be seen in disarray, moving this way, then that, before rejecting main party politics. The swing is generally uniform, particularly so in 1983, although by 1987 it had rapidly polarized.