A Dictionary of Music and Musicians/Bombardon
BOMBARDON, BOMBARD, BASS-POMMER or BRUMMER, were originally names of the deeper varieties of the oboe or bassoon family; the bombardon, or largest instrument, reaching to contra F. From these the name was transferred to a bass reed-stop on the organ, with 16-foot tone. In the 'Traité de l'Orgue' by D. Bedos, it appears that the stop was sometimes carried down to 32-foot F. It was mainly employed in accompanying plain-chant.
The name has more recently been given to the lowest of the saxhorns. It is usually tuned in E flat, for the convenience of military players, but a larger instrument in B flat is occasionally employed. There are two forms of the instrument; the one like the euphonium in shape, but larger; the other circular, passing over the performer's shoulder, and with the bell directed forwards. The fundamental note of the first is the E flat of the 16-foot octave; that of the second the B flat in the 32-foot scale.[ W. H. S. ]