d. The side sections are composed has also a lateral reciprocating motion, so that at each Long Island City, N. Y., which is remarkable for its of sliding members, the upper of which are raised by stroke of the rod the beater, after striking the cleaning- great efficiency and compactness. a… … A BLACKBOARD-ERASER CLEANING-MACHINE. ing devices to engage and raise the upper carbon to form the arc. surface of the eraser, tends to force the eraser out The merits of this construction are obvious. Only portions of the guy-ropes being connected at the same from the machine a given distance. The…
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