Plate 1. 'The Rainbow' / in the Book "Phenomena of Nature" [cover title]: 'Thirty plates illustrative of natural phenomena etc. with a short description annexed to each plate' [title page]. - / [illustrations] by Whimper [Josiah Wood Whymper, 1813-1903]; printed by R [Richard] Clay, Bread Street Hill. - London: SPCK etc, 1849. - Engravings, wood, coloured, in bound volume, 35x29x1cm.

Detail from an engraving by Whymper, plate 1 from 'Phenomena of Nature', published in London in 1849 for the Society for Promoting Christian Knowledge. 'The rainbow is one of the most beautiful appearances in nature, and is visible when the sun is shining brightly in one part of the sky, while at the same time a shower is falling in the opposite direction. In passing through the drops of rain, the colours of the sun's rays (namely red, yellow and blue) are separated resulting in the rainbow effect.'