Dom Pedro II Observatory, Saint Thomas Island, Danish Possession in the Antilles: Interior View of the East Part of the Main Central Pavillion with the Meridian Circle Telescope, Sidereal Pendulum and the Electric Chronograph


This photograph is contained in an album that commemorates the participation of Brazil in the international effort to track the transit of Venus in 1882. This involved the establishment by the Imperial Observatory of an observatory, named after Emperor Dom Pedro II (1825-91), on the island of Saint Thomas in the Danish West Indies (present-day U.S. Virgin Islands). The transit of Venus is a rare astronomical event that occurs when Venus passes between the Earth and the sun, becoming visible in daylight against the solar disk. The transits occur in eight-year pairs at intervals of more than a century. Since the 17th century, astronomers had been especially interested in these transits, as they offered the chance, using multiple observations and complex mathematical calculations, to determine the distance between the Earth and the sun (the Astronomical Unit). There thus was great scientific as well as public interest in the transits of 1874 and 1882. The album is part of the Thereza Christina Maria Collection at the National Library of Brazil. Composed of 21,742 photos assembled by Emperor Pedro II throughout his life and donated by him to the national library, the collection covers a wide variety of subjects and documents the achievements of Brazil and Brazilians in the 19th century. The collection, named after Empress Thereza Christina Maria, was inscribed on the UNESCO Memory of the World register in 2003.

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Subject Date

Publication Information

Virgin Islands


Title in Original Language

Observatorio D. Pedro II, Ilha de S. Thomaz, possessao dinamarqueza nas Antilhas: vista interior da parte de l'Este do grande pavilhao central contendo a luneta meridiana, pendula sideral e chronographo electrico

Type of Item

Physical Description

1 photograph contained in an album : black and white ; 21 x 15.9 centimeters

Last updated: May 24, 2017