Artillery slide rule
Slide rule
1960-1970
Dutch slide rule
1960-1970
Dutch slide rules
1960-1970
Dutch slide rule
1960-1970
Dutch slide rule
1960-1970
Dutch slide rule
1960-1970
Dutch slide rule
1960-1970
Artillery slide rule with cursor for range-finding
Wooden slide rule for artillery rangefinding
1816-1827
Altitude slide rule for ballistics use by Dring & Fage
1916