Seven (7) circular slide rules, including Dietzgen 1798 Dempster RotaRule Model AA, Loga. 1st item: Dietzgen 1798 Dempster RotaRule Model AA 50-Inch Pocket slide rule, designed and manufactured by Jack Dempster, Berkeley, California, sold by Eugene Dietzgen Company, Distributors, Chicago, New York. Comprised of two-sided round white plastic, with a clear plastic cursor and 27 handwritten scales labeled in red. Serial number 1516 with maker's mark and model number, front, additional maker's mark, patent number and date "1933", back. Includes one (1) leather case with snap closure and two back straps. Slide Ruler: 5 1/4" dia., with cursor: 6" dia. Case: 6" H. Note: This model is depicted in the 1938 Dietzgen Catalog (see: https://www.sliderulemuseum.com/Circular/Rotarule_Dietzgen_Catalog.jpg). 2nd item: Loga 30 Tt Duplex Scholar slide rule. Comprised of double-sided white metal with plastic and metal cursors and black metal frame. Serial number 61251 with maker's mark and model number, front. Includes one (1) Loga brown leather case with zip top closure and gilt lettering. Slide rule: 5" dia., with cursor: 5 1/2" dia. Case: 6" dia. 3rd item: Loga Modell Topo 6400 slide rule. Comprised of multicolored plastic with a plastic and metal cursor and metal frame. Maker's mark and model number, front, serial number 171 to cursor, back. Includes one (1) brown leather case with zip top closure. Slide rule: 5" dia., with cursor: 5 3/8" dia. Case: 5 3/4" dia. 4th item: Loga 30sT slide rule. Comprised of white and light yellow metal with a celluloid cursor and black metal frame. Maker's mark and model number, front. Includes one (1) Loga brown leather case with zip top closure and blue lettering. Slide rule: 5" dia. Case: 6" dia. 5th item: Aristo-Calculator 622 slide rule. Comprised of white and yellow plastic with a clear celluloid cursor. Maker's mark and model number, front. Includes one (1) Continental brown leather case with open top and blind stamped lettering and one (1) instruction manual with German text. Slide rule: 4 3/4" dia. Case: 5 1/4" H. 6th item: Cal-Math slide rule. Comprised of gold and light green aluminum with a clear celluloid cursor. Maker's maker, front. Includes one (1) plastic case and one (1) instruction manual with English text. Slide rule: 3 5/8" dia. Case: 4" dia. 7th item: Loga Simplex 30sE slide rule. Comprised of white plastic with clear celluloid cursor and black metal frame. Maker's mark and model number, front, additional maker's marks, back. Includes a brown plastic case. Slide rule: 5" dia. Case: 5 1/4" H. 8th item: Dietzgen 1752P 20 inch Maniphase slide rule. Comprised of one-sided celluloid coated mahogany, glass cursor with partial metal frame, front, laminated paper label, back. Maker's marks, front and back, model number, right edge. Includes one (1) black leatherette Dietzgen case. Slide rule: 21 1/4" L. Case: 21 1/4" L. 9th item: Dietzgen 1762C 20 inch Multiplex slide rule. Comprised of one-sided celluloid coated mahogany, glass cursor with metal frame, front. Patent number, front. Includes one (1) partial original cardstock case and one (1) outer box. Slide rule: 21 1/4" L. Case: 18 1/8" L x 1 3/4" W x 7/8" D. Box: 21 7/8" L x 2 1/4" W x 1 1/8" D. 10th item: Dietzgen 1797B Gilson Binary circular slide rule, made by Gilson Slide Rule Company, Stuart, Florida. Comprised of a two-sided enamel-coated aluminum circular disc with alternating green and yellow stripes with three transparent yellow plastic arms, two to the front, one to the back, pivoted at the center with a metal nut and bolt with metal washers on both front and back. Maker's marks front and back, dated "1940", front. Includes one (1) light blue leatherette open top case, one (1) instruction manual, and one (1) outer box. Slide rule: 8 3/8" dia., with cursor: 9 1/3" dia. Case: 8 1/2" H. Box: 1" H x 8 3/4" square. 11th item: Dietzgen B-1725-L Vector Type Log Log slide rule, made in Japan. Comprised of two-sided celluloid coated bamboo, frameless plastic cursor with plastic edges held together with metal screws, and L-shaped metal end pieces. Maker's marks, front. Includes one (1) Dietzgen brown leather case and one (1) instruction manual, housed on the original outer box. Slide rule: 13 1/4" L. Case: 13 1/2" L. Box: 1 7/8" H x 14 1/2" W x 6 1/4" D. Provenance: Private West Tennessee Collection. Condition: All items in overall good condition with wear to be expected from age and manner of use. 2nd item: Ink inscription from previous owner to back of case. 9th item: Case and outer box with black and white tape repairs. Outer box with dampstaining. 11th item: Slide rule and case are new in box.