Charming Odd Sized Trio of Vintage Circular Calculating Devices – Different Sizes and Functions This rare trio of circular calculating devices offers a fascinating look into vintage engineering and calculation tools from the mid-20th century. Each piece in this set stands out for its distinct size and design, with all three perfectly preserved in excellent condition. These tools are a true treasure for collectors of vintage mechanical devices, graphic design tools, or mathematical history. The trio includes: - Grafia 190 – The largest in the set, this impressive graphic industry calculator by Norma (DBGM) was designed to perform a variety of functions including multiplication, division, and conversions for commercial and graphical calculations. A powerful device for its time, the Grafia 190 still holds its aesthetic and functional charm. - Circular slide rule – A mid-sized tool in pristine condition, used for advanced mathematical calculations, such as trigonometry and logarithms, often used in technical and engineering contexts. - Aristo Mini Circular Slide Rule – The smallest member of the trio, a portable calculator in its original Aristo leather case, ideal for quick on-the-go computations. It maintains the signature Aristo precision and is in fantastic condition. Key Features: - Brand/Manufacturer: Norma (Grafia 190), Aristo (Mini circular slide rule), and an unnamed mid-sized slide rule - Materials: Metal, with protective leather casing for the smallest and largest devices - Era: Mid-20th century - Condition: All three devices are in excellent, preserved condition with fully functional rotating dials - Provenance: Carefully maintained over the years, part of my personal collection This unique trio has been a captivating part of my collection for years, but it’s time for it to find a new home where it can be appreciated for both its historical significance and decorative appeal.