Studied from its original page

Droites à doubles enveloppes

lines with double envelopes · trajectoires des contacts (the §108 variant)

Made by: Père Poulain (principle, letter to d'Ocagne of 16 October 1891); B. Paladini (contact-trajectory example on an equation of Pesci, Rivista marittima, March 1898); systematised by Maurice d'Ocagne
Year: 1891-98
Field: Nomograms and computing charts
Kind: Computing chart
Room: Charts that compute

Droites à doubles enveloppes — Plate from d'Ocagne 1921, Traité de nomographie, 2e éd.Internet Archive

See the original page — fig. 128, printed p. 315 (archive leaf n339)

Published 1921 (A) and the figure is a treatise illustration by d'Ocagne, who died in 1938 (B ended 2008). Poulain supplied the idea, not the drawing.

The data it needs

z1 input (grid abscissa) · quantitative
z2 input (grid ordinate) · quantitative
z3 input (envelope family touched) · quantitative
z4 output (envelope family, or contact curve, read) · quantitative

Built in 6 steps, as its maker described

ch. V §107, pp. 314–316, fig. 128 p. 315; §108, pp. 317–318, fig. 129 p. 317

Skeleton drawing, not the original plate

121 other forms share this skeleton

Source

d'Ocagne 1921, Traité de nomographie, 2e éd.

Attribution checked against the source

Searches, not citations

archive.org commons.wikimedia.org scholar.google.com