A rare Marey pneumograph amended by Charles Verdin, or an explorer of breathing. This was tied to a person’s chest and hooked up to a machine to measure their breathing rate (respiratory rate).

Signed Charles Verdin, circa 1885.

If Marey designed many models of pneumographs early in his career of physician and physiologist, this model appeared for the first time at the beginning of 1880s in the second edition of Circulation du sang published in 1881 (page 709, figure 343).