The Geneva Museum of the History of Science has a number of instruments from Geneva's first astronomical observatory in its collections.

Built in 1772 in the heart of the city, the Observatory's main task was to calculate the exact time by observing the stars and supplying it to the city's watchmakers. At the time, Geneva had a flourishing watchmaking industry, which produced 100,000 very beautiful, very expensive but also very inaccurate watches every year.

The Observatory's objective was therefore to provide the city's watchmakers with a perfectly linear mean time so that they could regularly adjust their watches. Among the instruments preserved in the Museum are a meridian bezel, a seconds counter and several astronomical clocks made in England and France.

During the 19th century, the Geneva Observatory continued to promote progress in local watchmaking by organising an annual chronometer-setting competition, during which watches were tested for several days in different positions and temperatures to reproduce the conditions of a sea voyage.

Astrophotography was introduced at the Stockholm Observatory in 1887. Following his return from the Astrophotographic Congress in Paris earlier the same year, observatory director Hugo Gyldén promptly commissioned a photographic objective from Steinheil in Germany. This objective, along with a simple camera house, procured from a Stockholm pharmacist, and some wooden tubing, was then piggybacked on the existing ten-year-old Repsold equatorial refractor. In the years that followed, Gyldén and his assistant, astronomer Karl Bohlin, later to succeed Gyldén, tried to grasp the workings of the new technology and to determine its potential applications. This was no easy task. Even after they had come to terms with the art of photography, its practical value for astronomical research remained uncertain.

This paper will outline the history of the Repsold refractor, and the astrographs used with it, with a particular emphasis on the astronomers’ efforts to make astrophotography relevant. It will also explore how this new technology eventually transformed the observatory's research program.

In my paper I want to compare two of Helmholtz's inventions which represent probably crucial developments in the attempt to turn telestereoscope, an observation device, into stereotelemeters. During a research visit at the university of Heidelberg I was shown the „Helmholtz Cabinet“ with a few select instruments, which were attributed to Hermann von Helmholtz and which could be saved from going to scrap when the Faculty of Physics was moved to its new premises.
The first of the instruments is the lenseless telestereoscope from 1857 by which Helmhotz could prove the importance of the extended optical baseline for stereoscopic observation. The second is a development of his, communicated 10 years later, which had a set of lenses applied to the basically same setup. Whilst it was already known, that lenses could be used to enlarge the observed objects or landscapes and hence improve the results of a distance estimation it was unclear, why he used more than two lenses in his double telescope. As a result of my research I could verify, that the „Telestereometer“ from the cabinet could well be the unique copy of the instrument, about which Helmholtz spoke in his „Handbook of Physiological Optics“ and which problem he tried to solve with this particular setup.

The circulation of language on scientific, technological, or medical topics changes its conditions of meaning. This paper traces how two famous lines from theologian Thomas Chalmers reappeared in new contexts across the century and the globe. In 1817, in A Series of Discourses on the Christian Revelation, Chalmers penned a passage comparing the telescope and microscope: “The one led me to see a system in every star. The other leads me to see a world in every atom.” The comparison of telescope and microscope was a well-worn trope, and this particular pair of sentences was quoted and recirculated many times over the course of the nineteenth century. However, Chalmers’s description of a microscopic “world in every atom” functions quite differently whether it appears in his original discourses to glorify God, or quoted by William Whewell to argue for the plurality of worlds; or quoted without attribution to venerate the microscope itself in an Illinois microscopical society newsletter, later reprinted in London’s Science-Gossip. These lines are quoted in one periodical to support evangelism and, in another, free thought; in periodicals arguing for the morality of American slavery and those promoting abolitionism; even in pamphlets reporting on the bloody 1865 Morant Bay Rebellion in Jamaica, cheek-by-jowl with Parliamentary reports on the matter. The circulation and adaptation of Chalmers’s words to these diverse textual settings shows how ideas of these scientific instruments informed diverse domains of nineteenth-century culture and, more important, could be adapted in new settings to serve new aims.