Artifact Details Title Log-Log Duplex Trig slide rule case Catalog Number XD50.76B Type Physical object Description Log-Log Duplex Trig slide rule case consists of a log rectangular case with flap and securing loop on one end. Logo "K+Σ" is embossed within a circle on closing flap. Handwritten text on the inside of the flap reads, "DICK CLAYTON | ΣAE". Manufacturer Keuffel & Esser Company Place Manufactured U.S. Identifying Numbers Other number 4080-5 Stamped on front of flap Dimensions 1/4 x 1 1/2 x 22 in. Category Office equiptment/Carrying case Credit Gift of Dick Clayton Lot Number XD50.76 Related Records XD50.76 Log-Log Duplex Trig Slide Rule