Gnomes are known for their intelligence. Any job that doesn't take advantage of their most-prized trait is looked down upon - janitorial positions, hand-hammerers and - worst of all - street-sweepers. Most street-sweepers were Trolls; immigrants who couldn't even begin to compete intellectually or magically against Gnomes in the job-market.
Street-sweeping, many thought, was a job that could be automated. But no matter their best efforts, the finest Geniuses in the land could not work out how to mechanise the process. Many had died trying.
It was the cause of a lot of mental anguish for a lot of inventors, who like to think that so many varied kinds of machines can be built that ultimately anyone and everyone will become redundant, but it somewhat a relief for the street-sweepers.
The main issue, one particular Gnome known as Tobius Tomni had concluded, after a few jackarandas and a night without sleep, was that streets weren't shaped in such a way that a broom rotating around a single point could effectively sweep the entire street. He had designed a street made entirely of semi-circles, and timed the mechanical brooms in such a way that the dirt would be passed from one to the next, until the end of the street, when all the piled up refuge was neatly swept into a deliberately-placed drain.
This was, by far, the most effective of the mechanical street-cleaning methods, although it still wasn't 100% efficient - dirt that a manual street-sweep would easily have caught remained behind. The main issue, however, was that it was a street made entirely of semi-circles, with sporadically-moving brooms that rotated along the ground and tripped you up if you weren't careful.
Eventually, the Tomni-model street was moved to a local attraction fair, and used as part of an obstacle course, where it was quite successful. Tobius went on to invent a machine that automatically placed hats upon your head, which ultimately found use as an execution machine.
Fantasy city by David Revoy, licensed under the
Creative Commons Attribution 3.0 Unported license.