I just added the below image and caption to the Trombone History Timeline (18th century).
c. 1720—Augsburg, Germany: Christoph Augengicht, Trombonist, a watercolored engraving that is part of a series of musical caricatures by J.A. Müller, shows a trombone with a slide that extends past the bell, but a back bow of tubing that does not quite reach behind the shoulder. The player uses an extension handle on the slide (see below image; public domain) (German National Museum, Nuremberg).
Seth
Interesting….what I find really curious is the ferret in the guys pocket…..perhaps to pick-pocket people he distracts while playing the trombone??
wkimball
Funny, I didn’t notice that. I think it may have registered as a handkerchief.