Moulin à café [Coffee Mill], 1911, painting (Tate Gallery, London)
- bill 1-14-2008 3:34 am [add a comment]

Geometrically speaking, the most interesting device of the Bachelor is the Chocolate grinder. Three conical frusta (the rollers) rotate (with a sliding component) on a conical chassis. The roller are carefully ruled with threads, as the coiling of a dynamo. This connects the Grinder device with electromagnetism, as definitively documented by Henderson. But Duchamp also spoke of the threads in terms of "generatrices" (Matisse, entry 36). Accordingly the Grinder is a very effective generator of ruled surfaces. This is fully consistent with Duchamp’s theory of "elemental parallelism" (Adcock, pp. 137-199) and with his interest in Marey’s chronophotography (Cabanne, p. 34). Supposing the Grinder at work, we obtain several ruled surfaces as geometrical loci of the threads. When the rollers slide without rotating around their own axes, the loci of the diametric threads are single-sheeted hyperboloids, which are actually mentioned by Duchamp (Sanouillet p. 83) as examples of geometrical objects which "lose all connotation of men-surated position" by passing into the Bride realm. Single-sheeted hyperboloids can be used to create a special type of gearing, very similar to that one depicted in the Coffee mill (1911). Even more interesting and complicated bands, belonging to the family of the Moebius strips, can be obtained as the loci of the threads (of both the slant heights and top or bottom diameters) under the assumption that the rollers also rotate around their own axes, while rotating around the Grinder axis. Again, rotation allows the Bachelor to emulate the topological essence of the Bride space.

- bill 1-14-2008 4:15 am [add a comment]

- bill 1-14-2008 4:26 am [add a comment]

- bill 1-15-2008 12:21 am [add a comment]