Dahl Mfg. Co. "Interlox" Master Slide Rule - vintage metal and wood - early 1900s
Antique Dahl Mfg. "Interlox" Master Slide Rule" telescoping carpenter's measure from c. 1911 to 1918. Wood and metal rule slides to expand rather than unfold. Made in New York City.
Historical details about this rule come from Walter Grutchfield. "American Carpenter and Builder, 1 Sep. 1911, pg. 104, noted that Dahl, with offices now at 1 East 42nd St., was manufacturing the folding ruler called the Dahl Master Slide Rule, "Carpenters, builders, glaziers, shademen, plumbers, in fact any one in the building trades that ever has use for a folding rule, should be interested in the Dahl Master Slide Rule, made by the Dahl Mfg. Co., 1 East 42nd St., New York. This rule is illustrated herewith, right side up, ready for inside measurement. The arrow indicates the exact inside dimensions. As can be seen this rule is particularly desirable for measuring the inside dimensions of doors, window trim, etc. When closed, the rule measures 8 inches."
SIZE 8" long when collapsed x .5" wide
CONDITION Used and antique. Ruler expands well until there are four segments left. It stuck and we respect this fine thing too much to attempt to force it with or extremely basic knowledge of such things. Best left to its new owner, says we.
This is a vintage item. It has been used and loved and it has a history. Please examine photos carefully and ask questions, as we are unable to accept returns or exchanges.