Londinensis. In the centre of the image is an eye within a star and surrounding this are seven figures representing the colours of the spectrum. In the four corners, putti are demonstrating optical principles and instruments: a telescope, a prism, refraction in water and a camera obscura.

The "Encyclopedia Londinensis, or Universal Dictionary of Arts, Sciences and Literature" was published in 24 volumes between 1810 and 1829, compiled by John Wilkes but published after his death. It aimed to make use of eminent authors and included many attractive engravings, most by J. Pass and J. Chapman. This is a line and stipple engraving with etched details.