A magic square is a grid arranged so its rows, columns, and diagonals share a sum. A British Museum silver amulet makes the Jupiter version a physical object rather than only a puzzle online.
- Source tradition
- Early modern Europe
- Object or edition
- British Museum OA.1405
- Descriptive label
- Planetary diagram
The four-by-four object
The British Museum describes a silver magical disc, OA.1405, engraved with a four-row, four-column numerical square of Jupiter. Its rows and columns sum to 34, and the numbers together total 136. The museum dates the piece cautiously to the sixteenth through eighteenth century and gives a question mark for its European place of manufacture. These qualifiers matter: a mathematical arrangement can be stated precisely while the object’s workshop cannot. Other inscriptions and figures appear on both faces of the disc, including an angelic protective figure on the reverse. A digital reconstruction of the grid is therefore only part of the artifact. The surviving metal, diameter, and two-sided composition are part of its historical evidence.
One mathematical shape, multiple traditions
The Metropolitan Museum’s study of Islamic arms and armor discusses lettered and numbered talismanic squares on blades, including a three-by-three form called wafq and a four-compartment form called buduh. Those are not simply the British Museum’s four-by-four Jupiter square with translated labels. The grids have different sizes, script traditions, and theological settings. Similar arithmetic or checkerboard form is an invitation to compare, not proof of common authorship. Within European planetary magic, a Jupiter attribution links the grid to an inherited astrological scheme; the sum itself is a property of the numbers. A historian can explain and verify that arithmetic without claiming that a planet confers an effect on an engraved disc.
A useful way to inspect a square
First count the cells, then check the numerical sums, script, materials, and surrounding figures. Record the institution and object number before giving the diagram a planetary name. A web graphic that shows only a clean 4×4 grid may omit the amulet’s reverse and uncertain date. Conversely, a museum caption can tell you the cataloguer’s identification while leaving open who wore the object and why. The Key of Solomon’s planetary pentacles are manuscript and print diagrams with their own witnesses; they should not be represented by this later silver disc. Related entries here discuss the Seal of Solomon and the pentagram, two more cases where a common graphic label conceals several historically different objects.