Circular Pocket Cornet by Metzler & Co.

By the late 19th century in England, circular cornets were often called "busker's bugles" but that was likely a slang term attached to them when they were out of fashion and not wanted by any but the peripatetic street musician.  During the 1850s and 1860s circular cornets enjoyed a certain popularity when the later form was not ubiquitous.   

This example has the added novelty of being very compactly wound and with an oval bell rim making it possible to transport it in a coat pocket or small satchel.  Judging by the somewhat rough and worn condition, it may very well have been the property of a street musician at one time.

Metzler was a music merchant in London from the early 1830s and likely didn't manufacture brass instruments there.  Other known instruments marked by Metzler include two other cornets like this one, a cornopean and keyed bugle but mostly flutes and clarinets.  This cornet was most likely imported from France in the 1860s.  It is 6 3/4" long with the shank removed, the bell rim measures 3 1/8" X 4 1/8" and the bore .449".  This cornet did not originally have a waterkey and the buttons, mouthpipe shank and mouthpiece are also replacements.

The lnext photo below shows a very similar cornet belonging to Mark Metzler (no known relationship). As similar as it is, it appears to have been made by a different European maker as if Metzler shopped this design around.

One last photo below is of another circular cornet from about the same time. This is the soprano of a family in this shape that was made by or for George Butler given the fanciful name “Butler’s Vibrating Horns”. The family included at least this, Bb cornets and Eb altos that I know of and presumably lower pitches. With more promotion, Henry Distin produced another family of circular brass instruments from Eb soprano to Eb contrabass with bells upright, which he called “Ventil Horns”.