Tuba after American bandmaster John Philip Sousa, resembles a hélicon with the bell pointed up (in the original models as the J. W. Pepper prototype and Sousa's concert instruments) and then curved to point forward (as developed by Conn and others). Some ancestors of the tuba, such as the military "bombardon", had unusual valve and bore arrangements compared to modern tubas. During the American Civil War, most brass bands used a branch of the brass family known as "saxhorns", which, by today's standards, have a narrower bore taper than tuba—the same as true cornets and baritones, but distinct from trumpets, euphoniums,
Brass instrument valve by Heinrich Stölzel in 1815) was an early variety. The piston valve found in the majority of valved brass instruments was invented in 1838 and patented in 1839. They are sometimes called Périnet valves after their inventor, François Périnet. They work by diverting air obliquely through ports in the stock of the valve so that a loop of tubing is included in the air stream, lowering the pitch. The stock of the valve is cylindrical and moves up and down through a larger cylindrical casing. The rotary valve works using a short circular plug housed in a larger cylindrical casing.