Johannes Maelzel was known as the inventor of the Maelzel Metronome-or M.M., as it is still abbreviated in sheet music.
Beethoven's use of metronome markings helped to popularize Maelzel's musical gizmo.
Another Maelzel invention, which failed to catch on, was the Panharmonicon. "Wellington's Victory" was commissioned and composed for this instrument, although it is best known today in Beethoven's orchestral arrangement.
The Panharmonicon was sort of like a barrel organ, but much more complex. It was capable of imitating not only all the instruments of the orchestra, but also, apparently, heavy artillery.
Although posterity has not always been kind to "Wellington's Victory," Beethoven himself was fond of it. After all, its several published arrangements made "Wellington's Victory" one of his most financially successful works.