Sonorophone. Nominal pitch: C / B?.

Technical description: Brass. Bell directed forwards and slightly upwards. The mouthpipe terminates in a ligature fitting which could either be for a tuning shank or for mouthpiece with a parallel shank. Long main tuning-slide, probably longer of alternatives for C and B?. Valve type: 3 rotary valves, with ratchet and pawl adjusters for clock springs.