Annuaire pour l’an 1879

Description

Paris Catalogue, Gauthier-Villars, 1879. 1 double-page map and 2 original photographs, paperback, original pink cover. Important issue of the Yearbook of the Bureau of Longitudes, containing the "Notice on recent progress in solar physics" by Jules Janssen (pp. 623-685): this important article contains two original laminated photoglyptic prints representing the surface of the sun, based on photographs taken on 1 June 1878 at 6:47 and 7:37 in the morning. These are among the first convincing photoglyptic images of the surface of the sun. Jules Janssen (1824-1907) began taking photographs of the sun at Meudon in 1877. Thanks to the photographic telescope built by the optician Adam Prazmowski, he succeeded, for the first time in the history of solar photography, in capturing the general "granulation" that covers the surface of the star. His photographs thus surpassed earlier attempts: those of the daguerreotype by Fizeau and Foucault (1845) and the photographs by Reade, Porro and De La Rue, taken in the 1850s and 1860s; indeed, they opened the way to important discoveries about photospheric structure and solar activity, since they made it possible, on the one hand, to highlight the importance of series showing the appearance of a sunspot from one day to the next, and on the other hand to observe that the surface of the star is divided into regions of relative calm and activity. This is undoubtedly the first scientific discovery due exclusively to the intervention of photography.