Jack was the pet and assistant of double leg amputee signalman James Wide, who worked for the Cape Town–Port Elizabeth Railway service. James "Jumper" Wide had been known for jumping between railcars until an accident where he fell and lost both of his legs. To assist in performing his duties, Wide purchased the baboon named Jack and trained him to push his wheelchair and to operate the railways signals under supervision.
After initial skepticism, the railway decided to officially employ Jack once his job competency was verified. The baboon was paid twenty cents a day, and a half-bottle of beer each week. It is widely reported that in his nine years of employment with the railroad, Jack never made a mistake.
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