Bank of Algeria (1851-1874)
From 1862, and as in France at the same time, the Bank of Algeria adopted the "celestial blue" color printing process in order to anticipate possible counterfeits by photographic reproduction. The very first Algerian banknotes denominated in francs issued between 1851 and 1870 are particularly rare and never appear for sale. These banknotes are unfortunately not yet listed in the Numizon catalog but were the subject of a book published in 2016 by Maison Palombo and entitled: "Banknotes of the Bank of Algeria, Tome 1, 1851-1870" . These banknotes circulated until the beginning of the 20th century, before being gradually replaced by the first two-tone banknotes from 1912 and the polychrome banknotes from the 1920s.