The pochette, also known as the "kit" or dance-master's fiddle, is a slightly odd variation of the violin. Invented at the end of the 16th century, it's heyday was in the 17th and early 18th centuries. Thomas Jefferson also owned at least two.
The dancemasters were a semi-professional group of individuals that would travel to tavern or event in order to teach dance, call dance (kind of like modern square or contra-dancing), or select a set of dances appropriate to the event, and they were paid a small fee for their services. The small "pocket" fiddle they played was shrill and not particularly rich or resonant sounding, but could pierce through the background noise of the dance hall or gathering and still be heard. Since many were simply hollowed sticks rather than elaborately assembled pieces, they were pretty sturdy and could withstand rather rough treatment.