Comparative sketches of mechanisms dated 1921 and 1931

In this document

This diptych brings together two sheets of handwritten pencil sketches, each dated separately.

Page dated 1921

Page 48 bears the inscription "1921" written in a rectangle drawn in pencil at the bottom right p. 48. The main sketch represents a side view of a chassis with two wheels (front and rear) connected by a horizontal shaft passing through a rectangular housing, and a more complex mechanical assembly on the right featuring a circle evoking a gear or a steering wheel, with letters "a" identifying a vertical element p. 48. Two smaller supplementary sketches at the bottom of the page detail a front view and a circular cross-section labeled "a - a" p. 48.

Page dated 1931

Page 49 bears the inscription "1931" in a rectangular cartouche at the bottom of the page p. 49. The central, denser sketch shows a mechanical assembly in cross-section/elevation: an arched piece (inverted U) crossed by a horizontal axis, associated with two circular pieces (one with a splined profile, the other a ring) drawn on construction circles, as well as a central assembly in cross-section with a spring and thumbwheel p. 49. Two supplementary sketches, connected by arrows, detail respectively a cylindrical piece with a helical spring and a circular piece with a toothed edge topped by a screw p. 49. A handwritten inscription at the top of the page remains uncertain ("Camr" or similar), and cannot be used with certainty.

Context

No external information can be attributed to this specific document: the sketches bear no author's name, no part title, nor any project indication. Furthermore, we know from the biographical notice of the collection that Paul Magès, born in 1908, did not join Citroën until August 1925, at 17 and a half years old (biographical notice): the page dated 1921 cannot therefore correspond to professional activity at Citroën, since he was 13 years old at the time and was in school. His attested research on hydropneumatic suspension only formally began in the late 1930s-1940s, with the first plans dated 17 February 1944 (Hydropneumatic suspension plans with differential interaction (17 February 1944)). Nothing in the transcriptions allows these two sketches to be linked to an identified Citroën project, and the 1921 date even invites caution regarding the attribution of the entire diptych to Paul Magès himself.

Archivist's perspective

The deliberate bringing together of two mechanisms dated ten years apart (1921 and 1931) suggests a technical comparison process — perhaps the evolution of the same type of device, or the comparison of two competing solutions p. 48-49. The increasing complexity of the second sketch, with its detailed supplementary parts (spring, toothed piece), could indicate a refinement of design between the two dates.

These sheets probably belong to a larger set of mechanical research from the same period; they can be put into perspective with other items in the collection concerning oil level devices or modified components, such as the Handwritten sketch of an air/oil tube replacing the oil dipstick, which testifies to the same approach using successive comparative sketches. Without a legend or signature, however, the precise attribution to a project — and even to Paul Magès for the 1921 page, given his age at that date — remains conjectural.