From: Die Erkenntniß der Krankheiten der Brustorgane aus physikalischen Zeiche n oder Auscultation, Percussion und Spirometrie: Nach Heribert Davie’s Vorlesungen u. eigenen Beobachtungen by Johann Friedrich Hermann Albers, 1850. Endplate.

Notably, this book was published only 4 years after Hutchinson’s treatise on the vital capacity yet his original design for the spirometer appears to have already been modified. The developer of this spirometer was not named in the text.