A multifoliate rose of visual rhetoric.

Disquisitiones Mathematicae

After the Jesuit astronomer Christoph Scheiner made his first observations of sunspots from Ingolstadt in 1611, but long before he depicted the Duke of Bracchiano surrounded by a beaded circle of roses and identically mottled suns in the lavish Rosa Ursina of 1630, the Disquisitiones Mathematicae was released. Supposedly based on theses defended by Scheiner’s obscure pupil Johannes Georg Lochner, this slender treatise illustrated both sunspots and solar faculae in woodcut diagrams far clumsier than the elegant sunspot-maps and honeycombed bears of the Rosa Ursina. Although page 65/I2 of this shows the maculate sun rising from a cloud in the east, the anti-Copernican diagram earlier in the book is my favorite by far. It combines both mathematics and a round of visual rhetoric drawn from Aristotle and supposed common sense, radiating outward in an unbroken circle of examples.

If the earth rotates about the center (marked with a barely visible C) along the polar axis ν/λ, an object dropped from point ν to the left would descend in a strait line; beaded like an abacus, the upper axis marked A depicts an object descending toward B in an invisible equatorial spiral, while the diagonals and dashed zig-zag at the right depict the conical spiraling fall of an object let slip from upsilon (Y). Physical illustrations occupy the remaining two-thirds of the disc. A crow (D) attempts to drop an unconvincing-looking snail (E) on a rock (F), which would surely disappear from beneath the snail (limax) as the earth rotated? Another bird (P) finds its nest on terra firma, instead of continents away; and another (which looks like a stork, although the Latin texts calls it gavia, which suggests a loon), dives for the water. Perhaps it might be a kingfisher, or something. In any case, raindrops fall from a cloud (H), a plummet fails to flagpole, smoke (K) ascends from a chimney (L), rockets are fired from things that look like the pitching mound from Peanuts, cannonballs fly in other directions than sideways. All of this (of course) was merrily pounced upon by Salviati and Sagredo on the Second Day.

Regardless, the multiplicity of arguments embedded in the circle creates a unique rhythm, and both reinforces and challenges our acquired notion of a directional page.