Electrical engineering slide rule, Elecktro model 1/98 by A. W. Faber-Castell, Germany in cardboard case with instructions. Electrical engineering slide rule 1960-1965
Dubilier capacitance electrical engineer's slide rule, designed by Philip R. Coursey and manufactured by John Davis & Son (Derby) Ltd., 1928. Used from new by Mr A.E.Bennett chief engineer at Dubliers, electrical component manufacturers at Park Royal West London. Dubilier capacitance electrical engineer's slide rule 1928
Nelson-Jones circuit designer's (10-inch) slide rule, designed by Key Electonics Bownment and made by Blundell Harling Limited with plastic sleeve Nelson-Jones circuit designer's (10-inch) slide rule 1970-1975
Pickett slide rule, model N-16-ES, with electronics scales designed by Chan Street, Los Angeles, in leather carry case Pickett slide rule