Jan Hewlius's compass

Jan Heweliusz's compass (1611–1687). A hand-made instrument signed by the scientist himself. The Gdańsk astronomer, who was very fond of Nicolaus Copernicus' hometown, donated this compass to the Toruń academic gymnasium in the mid-17th century. It was used by young students of the university to learn natural sciences. The compass later became part of the collection of the Toruń City Museum, and today it is part of the collection of scientific instruments in the Nicolaus Copernicus House. This is a so-called proportional compass, referred to in the literature as Galileo's compass. The instrument has the signature "I. David. Fe" and "Johan Hevelke/ Anno 1638". It was created in 1638 on the initiative and design of Jan Heweliusz, and an unspecified role was played by the unspecified workshop of David I. The Toruń instrument, like all proportional compasses, was used for mathematical calculations and mechanical conversion of proportions, as well as for comparing surfaces. It consists of two arms in the shape of slats, connected by a semicircular hinge, closed with pin latches. The ends of the compasses' arms are decoratively profiled, and their surfaces are precisely engraved with measuring scales.