Francis Baily observes Baily's beads during a solar eclipse

Background. Baily's beads are features of total and annular solar eclipses caused by the rugged topography of the lunar limb. While Edmond Halley made the first recorded observations in 1715, the term "Baily's beads" came into use after Francis Baily described the phenomenon to the Royal Astronomical Society in December 1836.

Observation. Francis Baily observed the solar eclipse of 15 May 1836 from Jedburgh in the Scottish Borders. He reported that the phenomenon, which depends upon the irregular shape of the Moon's limb, was vividly described, attracting unprecedented attention to subsequent eclipse observations.

Legacy. Baily's observations started the modern series of eclipse expeditions. His description of the effect, which relies on the Moon's irregular surface, was so vivid that it drew significant attention to the total eclipse of 8 July 1842, which he observed at Pavia.