Leaving aside electric pencil sharpeners, how do these machines work? The simplest modern pencil sharpner, in which you twist the pencil, uses what I've learned is called a manual prism. If you turn a crank, then you're usually operating helical blades to grind off graphite and wood.
This pencil sharpener from the 1890s is quite different. As far as I can tell, the machine positions the pencil against a grinding plate at just the right angle. YouTuber Resuce and Restore brought this antique back into service. It's one of several fascinating old pencil sharpeners illustrated in a playlist.
-via Steampunk Tendencies
dang that works really well
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