Francis Baily, astronomer, early 19th century.
© Science Museum / Science & Society Picture Library
Mezzotint made by Thomas Lupton after an earlier original painting by Thomas Phillips. During an eclipse of the Sun in 1836, Baily (1744-1844) noticed a phenomenon whereby the Moon appears to break up into a series of bright points. This is caused by sunlight shining through lunar valleys. The phenomenon became known as Baily's beads.