In an attempt to combat intonation issues without the need for triggers, Besson introduced their Enharmonic series.
These instruments featured two sets of tuning slides on the first and second valves, one of which is slightly longer than the other. When the third valve is pressed, air is redirected through a different path in the valves, such that the longer slides are used if the first or second valve is pressed.
The design didn't take off, as the extra weight (particularly in the lower brass instruments) wasn't popular.
This Enharmonic Trumpet has been fully restored. Serial number is 99xxx.
The engraving on the bell is quite extensive. The text reads:
"CLASS A Enharmonic Patented 50 MEDALS OF HONOUR BESSON & CO Prototype 198 Euston Road LONDON ENGLAND"
An additional engraving notes this instrument was imported to Australia by Paling
"W.H.PALING & CO N.S.WALES & QUEENSLAND"
Record suggest this instrument was manufactured around around 1912.