d rock maple and are accurately graduated. BLACKBOARD PROTRACTOR SCALE. For other angles than those i)rovi<led in the triangli-, a protractor isnecessary to complete the line of instruments for blacklioard work. It isfurnished in the rectangular form of a protractor scale of heavy… … The above engraving is a facsimile of a cardboard protractor for primarygrades, wliich is used in many public schools with great satisfaction. This instrument is four inches in diameter and is made from cardboardprepared expressly for this purpose and graduated with a very accu-rately engraved die.…
Kindergarten -- Equipment and supplies · Schools -- Equipment and supplies · Color · Trade catalogs -- Schools -- Equipment and supplies
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