I just added the below image/caption to the Trombone History Timeline (19th century—1826-1850).
1849—Bologna, Italy: A watercolor depicts a trombonist from the Bologna Civic Guard Band (see below image; public domain) (Istituto per la storia del Risorgimento italiano, Rome).
Henry Howey
http://www.shsu.edu/academics/music/ponchielli/the-band/instrumentation.html