| US Patent: 715,582 
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| Test Indicator | 
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| Patentees: |  
 | Fredric B. Jacobs (exact or similar names) - Quincy, MA |  | Harold D. Waterhouse (exact or similar names) - Quincy, MA |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Oct. 09, 1902 |  
| Granted: | Dec. 09, 1902 |  USPTO (New site tip)
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                        Joel Havens
 
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| Description: |  | Henry W. Williams - patent attorney |  |