J. W. Dunne's notions of 'dream travelling' in time were taken seriously in the interwar years (see his An Experiment With Time (1927), recently republished by Hampton Roads Publishing, Charlottesville, VA). J.B. Priestley dedicated plays including Time and the Conways (1937) to Dunne. H.G. Wells was interested in Dunne's ideas and corresponded with him, but was critical of some of Dunne's notions.

British researchers really did build Differential Analysers with the toy kit Meccano, beginning in Manchester in 1934 and continuing until the 1950s. Their most significant use during the war was probably in developing Barnes Wallis's 'bouncing bombs' for the Dambusters raid The machines have been studied by 'Meccano men' ever since.

I'm very grateful to Adam Roberts for his expert assistance with the Old English of the 'Testament of Eadgyth', and his invaluable support throughout this series.

Any errors or inaccuracies are my sole responsibility.

Stephen Baxter

Northumberland

May 2007