James Edwin Wide was a railway signalman in South Africa in the 1880s. He was also a double amputee. He purchased a particularly intelligent baboon as a personal assistant and named him Jack. Jack learned to do all kinds of personal tasks, most importantly pushing Wide to work in a trolley. So he spent the workday with him, and learned even more skills.
But the signal box is where Jack truly shined. As trains approached the rail switches at the Uitenhage train station, they’d toot their whistle a specific number of times to alert the signalman which tracks to change. By watching his owner, Jack picked up the pattern and started tugging on the levers himself.
Soon, Wide was able to kick back and relax as his furry helper did all of the work switching the rails.
It was a nice setup, as Wide engaged in his hobbies while the baboon did his job. But eventually, a train passenger complained to the railroad company. Read what happened then at Mental Floss.