Kathleen Schlesinger

“ Ger. Tuben, Tenor-bass, Bombardon, Kontrabasstuba, Helikon; Ital. basstuba, bombardone) — are a family of valved instruments of powerful tone forming the tenor and bass of the brass wind. In the orchestra these instruments are called tubas; in military bands euphonium (tenor) , bombardon and helicon (bass) .
The modern tubas owe their existence to the invention of valves or pistons (Ger. Ventile) by two Prussians, Stölzel and Blümel, in 1815. The tubas are often confounded with the baritone and bass of the saxhorns, being like them the outcome of the application of valves to the bugle family. ”

“ The bore of the Wagner tenor and tenor-bass tubas, in B♭ and F, is slightly larger than in the horn, but much smaller than in the real tubas. The bell, funnel-shaped as in the German tubas, is held to the right of the performer, the valves being fingered by the left hand. There are four valves, lowering the pitch respectively 1 tone, 1⁄2 tone, 11⁄2 tone, 2 tones (or 21⁄2 tones) . The harmonic series is the same for both instruments, the notation being as for the horn in C.
By means of the valves the compass is extended downwards an octave for each instrument. ”

“ The tuba is represented, together with the buccina and cornu, on Trajan's column in the scenes described by Vegetius.
During the middle ages the tuba was as great a favourite as the busine (see Buccina and Trumpet) , from which it may readily be distinguished by its marked conical bore and absence of bell. ”