US Patent: 1,393,970 
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| Geometrical Tool
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	        Patentee:
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 | James H. Roberts (exact or similar names) - Charleston, SC |  
 
 
 
 
 
| Manufacturer: |  
| Not known to have been produced |  
 
 
 
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        Patent Dates:
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| Applied: | 
Jan. 03, 1921 | 
 
| Granted: | 
Oct. 18, 1921 | 
 
 
 
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                        Ralph Brendler 
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        Description: |  
| This metal ruler features a built-in protractor arm, with a secondary arm which can be set at right angles to it. |  
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