An extremely rare and important mathematical square by Nicholas Bion featuring four Pied de Roi or “King’s foot” scales for Paris, Rhin, London, and Rome. This is the realized version of a design for multiple foreign scales in his Traite de Construction book of 1709 (plate 9, page 94 – see drawings in the image gallery). The scales are an important record and comparison of standard foot measurements of four major European capitals at the end of the 17th century. Paraphrasing Bion’s description of the scales in French on page 90, section P:
The construction of the pied de roy is not very different from that of the proportional compass. When one wants to only mark the Paris measurement, each branch needs to be around 5 lines; but when one wants to add foreign measurements, they may be larger. We will therefore report on the Paris measurement in comparison with the principle foreign measurements of Europe:
…The Paris foot is 12 inches in length, divided sometimes into 720, or into 1440 equal parts, in order to better express its relationship with foreign measurements; For example, the foot of Lyon and Grenoble are both larger than the Paris foot, having 12 inches and 7 lines. The Rhine foot (Germany), used in all Northern countries, contains 11 inches and 7 lines; The London foot 11 inches and 3 lines; The Roman foot 10 inches and 10 lines, etc…
Nicholas Bion (1652-1733) was perhaps the most well-known maker of scientific instruments at the turn of the 17th and 18th centuries. He was “Engineer to the King” and author of one of the most important books on scientific instruments of the time, Traite de la construction et principaux usages des instruments de mathematique (link below), first published in Paris in 1709. Bion worked in Paris at the Quai de l’Horloge under the signs Soleil d’or and au Quart de cercle. He supplied globes, mathematical instruments, sundials and mechanical devices made to a very high standard. See his trade card with portrait in the image gallery.
17 cm closed. Despite ample signs of use over 300+ years, a very rare and important piece showing standard European measurements of the 17th century.
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Instrumentum specializes in high quality 17th and 18th century scientific instruments for architecture, mathematics and navigation. We have collected antique instruments for over 20 years with a focus on early and rare European architectural drafting sets, dividers, and rules. If you are interested in something particular please contact us at email@example.com. Image galleries of our inventory can be viewed on Pinterest and Facebook at the following links: