The Museum of Science of the University of Porto, founded in 1996, has been collecting scientific instruments and teaching objects which once belonged to the institutions that historically preceded this university, within a timespan of two hundred and fifty years, namely, the Royal Academy of Navigation and Commerce (1803-1837) and the Polytechnic Academy (1837-1911). A few examples of instruments designed to keep, measure and record time have been picked out of the collection, and framed in the context of the purpose each one of those institutions was serving. As it is, an astronomical regulator, bought from John Roger Arnold, London, in the early days of the Royal Academy of Navigation and Commerce, is believed to have been used as an astronomical time standard, to set on time the marine chronometers of the training pilots, for the accurate determination of longitude through the by then well-established chronometric method. A clock that makes an electric contact every second, by dipping a platinum wire in a mercury filled cup, designed to superimpose a time signal on to the continuous recording of some physical quantity, stands out as an example of other similarly oriented instruments purchased in the early 20th century, when teaching physics at the Polytechnic Academy came to rely less on demonstrations and more on quantitative experiments. Also noteworthy is a photographic recording system that has been devised by the physicist Mascart in the early 1880s and widely used in French observatories, together with Lord Kelvin’s quadrant electrometer, to study terrestrial magnetism and atmospheric electricity. The annexation of a Meteorological Observatory by the Polytechnic Academy, in 1901, has contributed this system to the present collection. The appearance of electronics and electronic instrumentation and, consequently, of non-mechanical means to measure time, is represented in the collection of the Museum by the cathode ray oscillograph acquired from the Du Mont Laboratories by the Physics Laboratory of the Faculty of Science in 1946.

This presentation is based on work co-authored by Luís Bernardo.