Ten inch slide rule
Ten inch slide rule, faced with celluloid, with spare log-log slide as arranged by Lt Col H.G. Dunlop R.F.A. and C.S. Jackson M.A.
Ten inch slide rule, faced with celluloid, with spare log-log slide as arranged by Lt Col H.G. Dunlop R.F.A. and C.S. Jackson M.A. in case.
Ten inch slide rule, faced with celluloid, with spare log-log slide as arranged by Lt Col H.G. Dunlop R.F.A. and C.S. Jackson M.A.
Case for ten inch slide rule.