Willem de Sitter: The Twenty-Sixth Bruce Medalist

Often in the history of astronomy, chance meetings have changed lives. Readers of this series may recall the fruitful collaboration between Jacobus C. Kapteyn, "the astronomer without a telescope" at the University of Groningen, and David Gill, her Majesty's Astronomer at the Cape of Good Hope (September/October 1991, p. 145; May/June 1990, p.84). Gill photographed the southern sky from Cape Town, Kapteyn did the measurement analysis in Holland.