Making the Tube before the Seamless Model
You cannot imagine the amount of work to create a horn before seamless tubing became available. The worker would use a piece of sheet metal gotten from a rolling mill or, before the eighteenth century, from a stamp battery mill where ingots were made from copper mixed with zinc and hammered into brass sheets. J. Samuel Halle, in Germany in the mid-1700s, requested sheets (called No.8) and they were six feet square and 1 1/2 inch thick.
The tubing was placed over mandrels and brazed with spelter, filed and polished. He would need the help of this wife and they would work late into the night. It would require much expertise using different hammers and anvils in order to make the metal do what was required. Narrow tapers such as those in the mouthpiece were made by shrinking the tube over a tapered mandrel and pushing it through graded holes in a fixed block and then smoothing it off in a lead die or press.
Tubing could be bent into u-bends after filling with molten lead that was oiled to prevent sticking or by filling it with a concoction of pitch and resin. Creases needed to be taken out before working the bend with countersunk holes in a steel plate before melting. Where the metal was joined, it had to be a lap joint or butt joint under a collar and soft solder was used to join them. And we haven’t even gotten into the sockets that the mouthpieces went into! For true mouth cups, animal horn would be sawn off at one end, and you could create a blowing cavity by burning it out with hot implements was one method.
For much of the seventeenth and eighteenth centuries, musicians worked on changing the length of the instrument's tubing in order to expand the instrument's range of sound. This included adding the crook, an adjustable piece of tubing that could change the tuning and range of the horn, and later creating a system of various sized crooks that had to be changed every time a director wanted the range of the horn to change.
In 1816, Heinrich Stölzel, a German horn player, and Friederich Blümel, professor of Musicology in Kiel University, were granted a Prussian patent on a valve and rotary system for the horn. This copyright allowed a system of crooks to be replaced by a set of valves attached to the instrument to change the horn's pitch giving it much more flexibility in tone.