Gottfried Wilhelm Leibnitz (1646-1716) constructed the "highest fountain in Europe" for the Elector Sophie and her husband. The line was stowed for this. The Ernst August Canal shortened a loop of the line and the difference in height was used to drive pumps for the fountain in the Herrenhausen Gardens (and also for their irrigation) via water wheels. Since the Leine was used as a shipping route at the time, a lock was built for the ships.
The current structure was built in 1863-1865 to replace the waterworks with "an iron machine work with raised pipe." The fountain should shoot even higher into the sky, after all, with the help of Leibnitz's genealogical research, the electors at the time had now become kings of England.
For those interested in mathematics and high school graduates: Leibnitz, who is also called the last universal genius, and Newton (that's the one with the apple and the tree) developed infinitesimal calculus at the same time - but probably independently of each other.