Canon der Finsternisse, Theodor von Oppolzer 1887

Gallery 1 of 4, -1207 to -375

Among eclipse cognoscenti, the Canon der Finsternisse (Canon of eclipses) by Theodor von Oppolzer (1841-1846) stands alone in the pre-computer era as the epic compendium of eclipse calculations and maps spanning over three millenia.

Theodor von Oppolzer was a mathematician, geodesist, and astronomer and published many papers with computations for orbital elements of asteroids and comets. Oppolzer observed the solar eclipse of 1868 August 18 and was inspired by this event to begin the calculations of solar eclipses which culminated in his Canon nearly 20 years later. Oppolzer organized a group of ten human computers to divide the task of calculating 8000 solar eclipses and 5200 lunar eclipses. For each solar eclipse, points were calculated for the begin, end, and mid-point of eclipse and circular arcs were drawn between the three points, resulting in considerable inaccuracies in the geographic locations of eclipse paths. 

Within the Canon, the circumstances of the solar eclipses were summarized in a set of 160 tables with correlating maps. Each table and map represents a set of 50 successive solar eclipses. The fact that each table and map contains exactly 50 eclipses explains why they span irregular intervals of about 20 years, plus or minus a year or two.

Sadly, Oppolzer did not live to see the completion of his opus; he died the year before its publication. He is reported to have inspected the final proof-sheets of the Canon in the hours before his death at the age of 45.

The original Canon der Finsternisse is exceedingly rare and is found only within university or observatory libraries. In 1962, the Canon was reprinted by Dover Publications and translated into English by Donald Menzel and Owen Gingerich. This reprint is also difficult to find and commands a high price.

Sources

The original edition of the Canon der Finsternisse in German can be found in digital form at http://www.archive.org/details/canonderfinstern00oppo. The maps below and in succeeding galleries come from this source.

An abbreviated biography of Theodor von Oppolzer can be found at http://en.wikipedia.org/wiki/Theodor_von_Oppolzer

Because of the large number of eclipse maps within the Canon der Finsternisse, this collection of 160 maps is divided into four galleries. The three succeeding galleries contain additional commentary on the Canon.