Vintage Manual Sonometer elm the smoke on this print

the smoke on this print "moves" by way of a spinning disc and die cut metal sheet behind the art

shears and other tools

these products were intended to be more substance over style and meant to be a sensible alternative to other brands of the time (please see attached advertisement scanned from page 30 of the January 1924 edition of Harper's Bazaar)

MM - C-6177 - 110723

Zone of Germany

Vintage Manual Sonometer elm the smoke on this printc. 1950s 1960s; W. M. Welch Scientific Co. Chicago Hand crank sonometer, a musical and scientific laboratory instrument used to measure musical instrument string tension and wave mechanics. It works as such (from NYU): The sonometer lays flat on a large surface. There is a meter stick attached for reference. Strum the strings freely or hold down the string in different positions like a capo, to achieve different notes. Strike the tuning fork and strum