Found on the Boerhaave Museum of the Netherlands website.  Inventory Number V19429. Attributed to E. Zimmerman.  Height 46 cm, width 20 cm, depth 25 cm.  A somewhat unusual design since there appears to be 2 taps underneath the spirometer.  How they connect to the interior of the spirometer and how they were used is unclear.  The museum places it between 1900 and 1925 and it is likely from around 1910 since that is the time E. Zimmerman was known to be constructing spirometers.