This is an Italian Organum Mathematicum from the late seventeenth or early eighteenth century. I didn’t have a clue what this meant, but again, the museum’s web-site has the answer, it’s effectively a portable encyclopaedia.
The museum describes more elegantly than I could:
“The inside of the chest is divided into nine compartments, one for each of the following subjects: Arithmetic, Geometry, Art of fortifications, Chronology, Horography, Astronomy, Astrology, Steganography, and Music. Each compartment contains twenty-four small rods ending in a coloured triangular tip. On each of the nine series of twenty-four small rods are inscribed definitions and information on the corresponding subject. At least one rod in each of the nine compartments has a black tip and constitutes the application table, which gives the rule for proper use. To multiply 74 x 8, for example, one removes the black-tipped rod from the Arithmetic compartment and places it next to the rods carrying the numbers 7 and 4 at the top. The eighth line on the black-tipped rod gives the desired product.”
I think it’s delightful, Wikipedia notes just how important they were:
“Kircher adopted some of the ideas in the Organum from preexisting inventions like Napier’s bones, almanacs, and his own Arca Musarithmica. Like other calculating devices of the period, the Organum prefigures modern computing technology. Yet, due to its general lack of adoption, it remains an interesting but obscure footnote in the history of information technology.”
Nathan and Richard would definitely one.
