The interest for historical scientific instruments as attractive collectibles and important artefacts for history of science and decorative arts is quite recent and began only around the beginning of the 19th century. The universal exhibitions of the second half of the century, which were spectacular showcases of the conquests of a triumphant bourgeoisie, were unique opportunities for presenting and displaying them. At the exhibitions historical instruments were shown as precious relics bearing witness to the work of famous scientists or the pretended intellectual primacy of a nation, as masterpieces of applied arts, as antiquarian curiosities, and as objects for illustrating scientific and technological progress. Instruments were lent by universities, astronomical observatories, scientific institutions as well as by private collectors. The presence of historical instruments at the “world’s fairs” largely contributed to increase their status and stimulated the foundation of permanent museums of science and technology.