Sentence:  Two other machines exhibited by Whitworth… One was furnished with a reversing tool to plane both ways, and called, from its peculiar motion, a <WSD>"Jim Crow</WSD> machine". 
Meaning of the word marked with <WSD> tags:  A double-action planing tool invented by (Joseph Whitworth), in which the blade ‘jumps' to face the other way on the back-stroke.