Slide rules in original plastic bags have not been cleaned or aligned. Some collectors, including myself, like having rules that have been sealed since they left the factory. However, 35-40 years of storage have effect even on slide rules in sealed plastic bags: The metal end brackets have dulled; the stators are usually out of alignment and some grit has deposited the celluloid surface. The rules can be returned to 1970 condition with some metal polish on the end brackets and a wipe-down with Windex.
Soviet KL-1 Pocket Watch Slide RuleClick on picture to enlarge. |
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![]() Front scales: B, C. Rear scales: D, sin-1(D), and tan-1(D). The tan-1(D) scale is a spiral which covers angles from 1o to 45o. The two buttons are differentiated by colored dots. The black button turns front scales (which are locked together); the red button turns synchronized hands on both faces which serve as the hairlines would on a conventional linear rule. Rule appears unused but hinge on presentation case is broken. Two-page Instruction Manual, prepared by Mike Konshak of the International Slide Rule Museum, is in English. (The original Russian instructions are also available on Mike's ISRM Web site.) |
Used Includes Slide Rule, Presentation Case, Instructions Price $60 |
Click on picture to enlarge.
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Single fixed disk with two cursors
on front and one on the back. Eleven scales on the
front (including drill and thread specifications and a
scale for adding /subtracting common fractions). Ten
trigonometric scales on back. Outer scales,
which are the ones used for multiplication and division correspond
to a linear slide rule about 12 inches long. Body of
rule is an enameled aluminum disk.![]() Rule is a little dirty and chrome-plated central pivot is slightly rusty. Torn cover of instruction booklet has been taped; interior pages are undamaged but brittle with age . Case is missing. This is one of three circular slide rule models manufactured by the Gilson Slide Rule Co. of Stuart, Florida. Gilson slide rules were distributed by every significant slide rule manufacturer /distributor in the United States but the Gilson name appears nowhere on the rules or in the instructions. (The distributor’s name was usually printed on the cover of the instructions.) Gilson was a small family business which moved from Michigan to Florida in the 1920s and set up on an undeveloped parcel of land accessible only by boat. We have corresponded with Clair Gilson’s daughter who remembers sewing slide rule cases on the family sewing machine. |
Used Includes slide rule, instructions. Price $15 |