Full name: **Astronomical telescope with a Gregorian mirror system** This type of telescope was first described in 1663 by James Gregory (1638-1675), a Scottish mathematician and astronomer, professor at the University of Edinburgh and St. Andrews University in Scotland. Inventor of the first reflecting telescope. He proposed a method of determining an astronomical unit based on observations of the transit of Venus in front of the disc of the Sun. This particular telescope was engineered by Jesse Ramsden (1735–1800), optician, maker of scientific instruments, mainly astronomical and navigational ones, Fellow of the Royal Society in London. **For more images and further information, visit:** https://muzea.malopolska.pl/en/objects-list/2778 Inventory number: 4044; 42/V Localisation of the physical object: Jagiellonian University Museum Collegium Maius, Kraków, Poland **Digitalisation: Regional Digitalisation Lab, Małopolska Institute of Culture in Kraków, Poland; “Virtual Museums of Małopolska” project**