“L’exposition universelle de 1867”

"Vue officielle a vol d'oiseau"
Eug. Cicéri, Ph. Benoist Del & Lith.
Pierre Petit Concessionnaire
Imp. Lemercier & Cie, Paris
Berlin, verlag von Goupil & Co. ; Paris, publié par Goupil et Cie ; New York, published by M. Knoedler, 1867.
Handpainted lithography , 680 x 985 mm
Library of Congress, Washington

The great Universal Expositions were inaugurated in London with the Great Exhibition of 1851 Born after the Industrial Revolution, they were spectacular events which, with a majestic set-up, showcased the fronteers of scientific, industrial, and artistic advances to the western world. France followed the example given by London arranging one Universal Exposition in Paris in 1855. The Expo of 1867, again in Paris, was intended to celebrate the glory and successes of the second empire of Napoleon III. The high point of the expo was the huge building made by glass and iron with elliptical shape, able to host up to 52.000 exhibitors.
Pio IX, keeping into account the suggestions from Secchi, who he always had appreciated, financed the building of a meteorograph, to be exhibited under that circumstance. Beside the scientific considerations proposed by Secchi, that decision obviously had also a political motivation: the meteorograph would be a spectacular symbol of the scientific dynamism of the Papal States.
The instrument, working perfectly, was exhibited in the section n. 12, devoted to the”instrumets de précision et matériel pour l’enseignement des sciences”. The majestic meteorograph(more than two meters high) looked after by its inventor always ready to give explanations, aroused the wonder and the admiration of the visitors, among them Napoleon III himself. The Jesuit François Moigno, famous scientific popularizer and editor of scientific magazines, not hesitated praising Secchi and his instrument, which he defined as “the gem of the exhibition”. The meteorograh was also described and illustrated in several volumes and issues printed for the exposition(Figure 1).
The official recognitions soon arrived: the specialized jury conferred to Secchi the Grand Prix; Napoleon III offered to him the officer’s cross of the Légion d’Honneur (figure 2), while the emperor of Brazil Pedro II, fond of science, appointed him Gran Dignitary of the Order of the Rose.
Despite the undoubtful success gained in Paris by the meteorograph, its diffusion was quite limited. The instrument was complex, it needed a very complicated set-up, and above all, it was extremely expensive (18.000 gold Francs). Also two simpler and cheaper models were proposed( 10.000 and 3.000 Franc, respectively), but they received few orders. Some of the orders came from the Jesuit colleges in Cuba, India and Philippines, and for this reasons there were facilitations with them. No trace was kept about the meteorographs provided to the observatories of Palermo, Manila, Avana, Calcutta, Zikawei in China, and to the Signal Corps of Washington, decommissioned after some years, or destroyed by natural catastrophes or during wartime. Nowadays only the magnificent instrument preserved in the Osservatorio Astronomico of Rome at Monte Porzio survives, spectacular testament of Secchi’s talent and of his work in the meteorology field of work.
After his stay in France, Secchi went ot England, where he could visit several institutions and meet several colleagues, among them John W. F. Herschel.

Paolo Brenni, CNR-IGG