"the passion of his life was pigeon-flying"
Photograph of a typical pedigree Racing Pigeon, bred and shown by Frederick Romer, Esq., prize-winner in races from France to England (1911)
Public DomainPhotograph of a typical pedigree Racing Pigeon, bred and shown by Frederick Romer, Esq., prize-winner in races from France to England (1911) - Credit: Encyclopædia Britannica

This may appear a somewhat odd detail in the novel, but the sport of pigeon-racing had achieved considerable popularity in Belgium by the mid-19th century. The pigeon fanciers of Belgium were so taken with the hobby that they began to breed pigeons selected for fast flight and long endurance called Voyageurs. From Belgium the modern version of the sport, and the Voyageurs which the Flemish fanciers developed, spread to most parts of the world.