A significant two foot wooden slide rule.
This is a Hawthornes Rule. based upon Routledge type rules. For an excellent article on this rule -The Rule Book by Jane Rees page 157 has a detailed description. If you do a web based search on Hawthorones Rule you will find a large amount of information from some excellent prestigous sources. And of course Philip E Stanley in Source Book for Rule Collectors has excellent articles on this type of rule.
This example made by Sam Brooks 1828. The photos show many details of the rule. It has suffered some wear and has a repaired split in one arm along with various usage dings. Still a very uncommon rule with wonderful patina. And a must for the rule collector.
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