Unequal refrangibility of two differently coloured lights Size:Standard: 14.8 x 10.5cm with boats and barges on

with boats and barges on the Thames

An accident in which a spectator was injured in 1925 led to the banning of all speed events on public roads

16th June 1982

In this posthumous portrait

Poster advertising Peugeot bicycles

Unequal refrangibility of two differently coloured lights Size:Standard: 14.8 x 10.5cm with boats and barges onExperiment to demonstrate the unequal refrangibility of two differently coloured lights, an illustration of Newton's first proposition, "Lights which differ in colour differ in refrangibility". From Contributions to solar physics, by J Norman Lockyer (London, 1874). Original: engraving. 1874